http://www.8051projects.net/ Learn to make simple microcontroller projects, pic, 8051, avr and arm projects. download 8051 projects, tutorials, libraries, sample codes. join the microcontroller discussion forum and ask doubts regarding electronics. the best source for 8051 over internet. Thu, 20 Nov 2008 20:15:28 -0800 http://backend.userland.com/rss092 hI,How can i make a sensor for checking moisture in soil and air humidity? ckts on the net not working! I am working on a control system which needs t <noauthor@nospam.com> http://www.8051projects.net/forum-t5757.html kts on the net not working! I am workingyou might be missing something... people in our field seldom upload their work unless tested.. give us the r shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Shyam,Finally my soil moisture sensor is working. I have not tested it fully. Will upload the ckt and resposnse voltage ranges for it. I need to ma Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html LDR is good for light sensing. or a photo transistor for a better voltage o/p Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html look here for humidity sesnsor: http://www.sumeetinstruments.com/sensors.htm sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Shashi thanks for the link. I tried mailing them as no details are given on the site but the mail couldnt be sent, probably the company has shut down! Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Maybe I can help you with the humidity sensor, Amit, it is HIH3605 from Honeywell. Linear O/P 0.8-3.9V at 5V supply. Details at Honeywell site. Produc Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html LDR is actually a variable resistor who's value changes according to intensity of light falls on it. Resistance of LDR is inversely proportional to li Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Hi ajay i know about the LDR but the problem is that the voltage across it switces instantly in a dark/light condition. so it effectively gives only 2 Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html hmmm il try that out... need to get to the lab for that. as of now the quad opamp gives me 3 leves. the reason i dint use the LDR as u mentioned is be Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html do not use opamp... try connecting LDR between ADC and VCC directly... something like this..         &nbs Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Ajay,I tried doing the light sensor the way u mentioned but i am not getting a varying voltage response! why is that? the voltage just switches fro Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html The LDR's resistance can reach 1M in dark conditions and 100 ohms or so in full brightness.So it naturally follows that you'll get an instantaneous sw sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html thanks sashijoseph for this info i did not know this thing about LDR. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Hi shasi,Thanks for the update! Il surely check it out today and let u know about the results Thanks for the link too. Il try getting the IC. Need Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html To add some finer points for Amit with LDR and LM35 Most of the ADC chips works with 5V, so its better to power the LDR from 5V too. As for the circ Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Yes Amit, contact Mr. Paresh 09967022244 02223869472 of Precious Electronics Corporation, he placed at Mumbai, tall him you got this information fr Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Shashi the ckt wrked like a charm! thanks a million. My board size has become 1/4th of wat i made!!!I am using it with 5V supply only.Chiru, thanks fo Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hey,It seems the 3605 and 3610 are outdated and now only the 4000 series are available @ Rs. 750+VAT!!! Also i am unable to find a circuit for it onli Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Dear Amit, the HIH4000 is smiler to 3605, find the same in the pdf, download it with search for HIH4000 pdf . As for temp compensation, i don't thin Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Chiru,Thanks for the info.I did go thro the datasheets earlier but...they dint make much sense to me I am able to get the HIH4000 locally @ Rs Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Chiru,No issues with the late reply. My work's on hold anyway! I think i have developed RSI. Bad pain at the left back of my head, neck and shoulde Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi...with 3605 measuring humidity is a cinch.You don't need that exotic dallas chip.You can easily use LM35 for temperature compensation.Just measure sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey shashijosephThanks for the post. Well the formulae for using with the 3605 is given in the document i had uploaded. But i am not getting the 3605 Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi, sorry for being late to reply . Sashi has already clarified something. But i think you can go straight and use HIH4000. No LM35. Just feed the p Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit get wel soon . ASCX and ASDX series pressure sensors are from honeywell (formally Sensym). ASCX is temp compemsated but costly. Both ASCX an Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Chiru,Thanks a ton for the good wishes and ur prompt replies really boosts my morale!!! il surely try and add the sensor for the water level ind Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, I think you are familiar with ADC conversion. If not, first try with 0804, try the "free running connection" in the Harris Semiconductor data Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi chiru, il look into the datasheet of 0804 as u mentioned. I used the NS 0808 with i/ps in the range 0 to 5V either from my sensors or variable sup Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit,The LSB of the digital o/p may drift a bit even with a stable analog i/p A steady clock is required at the CLK i/p for the functioning of th Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi chiru,Thanks for the info.Yes I did meant START (Pin6) by SOC. I had shorted it to EOC basically to use it free running mode (for continuous conver Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi amit, you can take some info from tutorial section if you want.. and keep working for learning you are doing a good job. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Ajay il surely look into the tutorials. i hav exceeded my bandwidth for this month so wil do it on 1st march only. u guys are really help Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html You don't need those Schottky diodes.They are used for supplying voltage from the 1-wire interface.You wouldn't be using that Dallas chip(in the attac sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Ajay and Chiru,Pls read the 1st post on this pg.Tried with the 0808 today as u mentioned, but i used it in free running mode and not with uC. so i Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, ADC0808 has max error of +/- 1/2% against 1% of 0809, it is a superior converter BAT54S is dual Schottky SMD diode, you may use two BAT42 o Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Chiru and Shashi,I dunno wats wrong, the ADC doesnt seem to be consistant at all! Behaves wierd!!! Today i tried it agin. Started with 1.5V (in Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Maybe a noise issue for the ADC.......have you used long wires at the i\p?Have you used a regulated power supply and proper bypass caps at the AD sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, i don't know if the 0808 is bad , but in case you plan to buy a new one, shift to serial ADC (saves space) and buy MCP3208 . It is 8 ch s Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Chiru....how much does it cost buddy? sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html What cost, Sashi Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html OMG!!! Well the cost of my proj is going up!!! Well, today i tried again with the 0809 and guess wat at IN7 i got precise digital o/p!!! exactly the s Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi shashi n chiru,Well i am using a IC trainer kit in my college lab and using the power supply n gnd from that only. i have not added any bypass capa Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Yes Amit, all serial ADC's are dear. A 2ch will be around 120/- and 8ch as high as 400/- in Kolkata . Give me some time, i shall get back to you wit Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Well Amit, since one of the i/p is working, the ADC is not bad . You say the address is ok, still once more check it as, for ch7 it should be #7 (al Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hmmm, i did give it enough time for the conversion and yes, i did follow the addresses correctly. will try it out again els i have got a new 0809, wil Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Take it cool, start it afresh Checked flickr, excellent, thanks and regards to your friend. Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Tried afresh with the new adc but the same prob :'( But found something interesting... the IN7 works even in the new IC. also the junk o/p is the same Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Take the plunge buddy.For now stick to the 8051 since you learnt 8051 programming.Try out a few projects with ADCs,I2C,SPI,LCD etc etc and then you ca sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, follow Sashi's suggestion In case you need to change, shift to PIC, start with 12F675 There are lots of circuits and projects available Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html that opamp is for calibrating the LM35 to obtain precise results.If one ortwo degree error will do for your application,then you don't need it. sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Shashi and Chiru,Il keep that in mind. I did start reading on the PIC 16F74. But there are no good books on them infact few ppl i asked said th Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html yes opmp is needed to fulfill the "signal conditioning"you can also use a divider network for this.but as sashi said , you can connect lm35 directly w abbas1707<abbas@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks a lot. il keep that in mind. wil be caliberating my sensors tomorrow for use wit the adc. and the next step is the programming.I wanted to know Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, to start with PIC, download the book "PIC in Practice A Project based Approach 2nd Ed." Its available for download in this site itself (in fa Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Yup Chiru is right......with a uc there's no point doing it manually and moreover in free running mode how will you decide exactly when to read in the sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hmmm oki. Il keep that in mind. the basic reason i thought of not giving al signals to the uC was to save the i/o pins as il be needing quite a few. I Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html You can follow Mazidi for programming the ADC.And for starters you may follow these steps......while(1){get_adc(temp) x 10 => T //get 10 samples sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hi shashi thanks for the idea. this was basically wat i had in my mind. but i had not thought of having the avg of 10 values. as i thought il keep dis Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html and another prob! i have not got a hold on programming the uC in C so i am stil stuck to assembly level programming only You call it a problem?Many wo sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html well thats the reason my preference for newbies is to use assembly first rather to go for C. C makes you lazy and you find things very very hard if Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Wel my skills in assembly are nothing great either... but farely decent. Regarding the clock, using timer is a very good idea as there wil be no synch Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Don't worry ...... we all make mistakes.I remember wiring a 78L05 like a 7805 without caring to read the datasheet and then ending up with a lighter p sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hmmm il surely keep that in mind. Its been a real learning though slow experience for me. hope i can get this power supply sorted out tomorrow. I have Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html sure start a new one.. coz it will be easy to have a follow-up then Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Okay! Now I am thoroughly confused!!!I tried making a look up table for the LM35. But i realised I need to have 2 separate LUTs, one for the ten's pla Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hey. Hows everyone? looks like its been a busy monday for all Mine too. I finally hav my power supply up and i am getting +5 & -5V!! Hurrah!!!An Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, couldn't keep in touch, was busy at Mumbai Give the blue print of your project, we shall try to help u with the code Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html nice to see more helping people around good work Chiru and Shashi... Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Hey am so sorry for not posting for over a week. My connection was down. Thanks to BSNL!!!! Wel it was finally set right today. Besides that i was stu Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Reply pls am waiting.. Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Step12 "initialise LCD' should be before step2.Polling the EOC would be better and simpler since you have to wait for the adc data before moving forwa sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Soory about Step12!! that was foolish of me!Could u pls tel me the link or the thread where that algorithm is by shyam?Thanks a ton Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html This is the thread.....http://www.8051projects.net/plugins/forum/forum_viewtopic.php?5070.40#post_7316 sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Shashijoseph,I am unable to follow that algorithm. N my C skills for 8051 are pathetic so understanding that code is impossible for me! Pls could Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html There is nothing difficult in it..its same like taking average of 10 values..you add all 10 values and divide it by 10, so you get average.Now when ne Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html oh oki got it now! i am such a dumb*** I thought it was wat u mentioned but was not sure. I am presently coding for the system using 1 sensor only. On Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html if you feel any problem using LCD, you take a look at LCD tutorial..why would i need the code? Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Wel i did go through it. So quite a few of my doubts have been cleared am not sure on how to make those custom characters. I need to display % symbo Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html '%' symbol is there in LCD isn't it? try..CODE: unsigned char string1[] = "this stored in ram";
unsigned char code string2[] = "t Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Ajay i really dont follow the c codes! pls help me in assembly (if its not too much of a trouble)... Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html well its same as you do in C..lets say adc_read is your routine for ADC thenCODE:
;for first time
acall adc_read
mov adc1, A
acall Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html hi amit...forget abt the barrel shifter code a the moment...there are several other DSP algorithms that can be used...today i m gonna start a new thre shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html Hi ajay, sorry i went offline suddenly! Had a power cut due t heavy rain I suppose!Hey Shyam thanks a million! il have a look at that thread... hope i Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html regarding LCD ..yes Amit u r right +led =>vcc -led =>gnd and they r for backlight... shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html The o/p of the ADC is definitely binary(hex).For eg. if the input to the ADC(configured with 0-5v full scale) is 2.5v,the output of the ADC will be 12 sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks a lot!!! That gives me some work to do for tomorrow! mu uC board was on hold cos of that +/- LED doubt of mine. My code (for 1 sensor) is a Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Well, i forgot to ask. is there any way i can improve the sensitiviy of the temp sensor? I mean in the present set up i cannot show decimal values, ri Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html which temperature sensor you are using?when taking average values.. you can get decimal values too.. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Shashijoseph and Chiru, thanks a ton for the repeated support and prompt solutions I checked the o/p of my bridge rectifier, was getting nearly 7. Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html remember that the transformer current rating is the maximum capacity which it can sorce and not the actual current it is sourcing pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Ajay, I am using an LM35. But not connecting it directly op the ADC, I am using an opamp as Shashi (or Chiru. dont remember) told me it wil help to Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html The LM7805 needs atleast 2V for dropout,ie ~7V at it's input.A 9v xformer would be better. sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks a lot. Yup no problem take ur time... ur doing us noobs a big favor by helping out on the forum i admit. Regarding the supply, I was told t Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html A 6V AC will give over 8V DC if not heavily loaded and should work fine with 7805, still its better to use a 9V one as Sashi suggested. Moreover there Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks...Anyway, I find this model, dunno can be used or not. It is from nemoto japan, http://www.nemoto.co.jp/en/products/sensor/manual/nhs-20.html o rbk23<dmxreebok23@nospam.com> http://www.8051projects.net/forum-t5757.html 3A for an embedded system is OVERKILL big time.With a cap(~1000uF) on the bridge,a 6v trans. should supply ~8.4v,but if it goes below 7v under load th sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Amit, employ a proper adc loop rather than reset Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi shashijoseph,Thanks a ton Il include those 4.7k resistors b/w the port and Vcc.I had got thoroughly confused with the switch! thanks for clearing Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Just saw this in a thread "ABOUT MICROCONTROLLERS" by TPS:-۞ TPS ۞ wrote ... ABOUT THE Microcontrollers A: Port 0 has open drain outputs. Ports Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Nope......between Port and Vcc (pullup). sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Also one more doubt, to trigger INT0, i am using a push to on switch similar to the one which is used for the reset switch of the uC. now, one end is sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey i got a solution to the problem. Just tell me if my logic is not faulty!!!In the ISR, After displaying the actuator status, there is a 5sec delay Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Had a brief look at your code.Like Ajay said you should initialise the LCD only once whereas you've done it 3 times.This is how it should be:1- initia sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html why are you initializing lcd again and again? I mean just use lcd clear command to clear lcd instead of re-initializing. Init part should be just once Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html have read all the details of your project. Am confused about your power supply part. I havealready used all the components you are using and in fact h pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html ajay is right . Why reset the whole uC when you can just refresh the data?? pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Ok i am terribly confused now :'( i dunno wat to do. I hope u understod my concern regarding the display. Il upload my code pls do go thro it and sugg Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hmmm thanks alot, il incorporate all the changes into the code and the hardware. Am facing a peculiar problem regarding the power supply. I am unable Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html it doesnot matter if u use a higher current txformer as long as ur curcuit does not sink more than 1amp current, go ahead and use it pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html where is the code? pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html oh i attached it... il do it again... Yup i know that about that transformer maincode1.zip Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html you can use 10K of resistance for pullups..use a resistor pack which is far easy to solder on board. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html hey thanks a ton! you simplified so many things in my code!!!This is a very good idea. But i had a doubt. Now when the user presses the button for vie Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html seeing your code. one common mistake is that u have not pushed the registers r0,r7 and accumulator before executing the ISR. this may corrupt their va pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html oh oki il do that! dint realise that it could create a problem.I was under the impression that the the uC takes care of pushing all reg values etc to Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html another problem is the 'conversion' routine. in the adc routine, u store theadc value(binary) in 'BUFFER'. now this when converted to BCD can be a two pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html i would suggest that u first write the LCD interface part, then add the ADC code and finally the actuator logic. Step by step debugging usually saves pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html push only the registers which are used mutually by both your main code and your ISR. and yes if you are using a different register bank in ISR, u need pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html check this code. i donot know from where i downloaded it . good reference. it gets value from ADC0808 and displays it on lcd. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html oops cannot upload asm files. will attach it in zip format adc0808.zip pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Now when the user presses the button for viewing the actuator status, wont there be a big time lag before the actuator status is displayed on the LCD? sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Oh oh... so many mistakes!!! dint expect this to happen!!! Regasrding the conversion routine:pdi33 wrote ...another problem is the 'conversion' rou Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Regarding the Port 0 quiery i hadIs this how i must use pull up resistors to all the pins of port 0? I have already soldered my LCD so will have to im Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html ur logic is fine amit, so go ahead . i was confused about the ASCII_RESULT part as it is only one byte long so it can take ASCII value of only one di pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Regarding prgramming the uC, i couldnt do it today! The programmer refused to be detected vy 3systems in my lab! So we assumed it was faulty but my gr Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html a Resistor pack is an array of resistors with one end of all resistors connected to a common point. See if you can find a 4.7k , 8+1 resistor SIP. the pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html note that the heat sinking fin of the 7905 is not internally connected to gnd like the 7805. check whether it is accidentally connected to ground. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks a lot for clearing those doubts. Regarding the power supply, I am using the center tap (ie 0-6)of a 6-0-6 transformer. I shall be changing Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html if u r using a centre-tapped txformer then the ciruit in supply.pdf wont wrk buddy. For that ckt u have to use two seperate windings.do this:connect o pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html o.k. u do not worry about the supply part buddy. just modify ur ckt according to this ckt attached. power_supply.pdf pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html sorry wrong attachment. check this file power_supply.pdf pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, don't get yourself confused follow the circuit given by pdi33. Take care with the pin config of 7905 it is not same as 7805. 7905 wont Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Amit, try and implement some part of the adc code supplied by pdi Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html cool down amit. take arest when things don't work out as expected. play some games in the arcade section. thee are some real cool games out ther pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Chiru and Pdi33,Thanks for being so supportive Frankly the whole thing is getting onto my nerves! Nothing seems to be working right and the submi Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html fig. (a) is good and only one 10E is required.regarding the power supply query, dear amit, only half of the voltage i.e. voltage from center tap to on pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks a lot got to learn so much from ur post! The only silver lining to my daily hurdles is that i am getting to learn something everyday... and Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html You can use the 6-0-6 for now.Later get a 9-0-9.You need only one bridge between the 6-6 points of the transformer.So the output of your bridge is +6v sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Yup its clear now Thanks a lot... God i am such a noob! BTW my groupmate came across LM833 opamp which only needs +5 n gnd, no -5 so if the supply c Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html If u are using the negative supply only to power the op-amp and not in any other resistive circuit, then u can generate -5V from +5V using a voltage c pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thats a good idea. incase ur clt doesnt work (which i am sure is very unlikely )then i can try this...or the LM833 also. Well i am only using - Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html if u want to use a cheap single supply op-amp lm358 and lm324 are good options. I have worked with both of them and they work very reliabally near gro pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html oh oki. 324 needs a -ve bias too right? like the uA741 Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html not necessarily. it can operate on only positive supply buddy. In fact 741 does not operate efficiently on single supply. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html And regarding the relay u mentioned that 12V would be needed right? but i thought 5V should suffice. I had done the same for a ckt i did in class 12. Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html If u still have doubts for 324, use 358 which is built for low power consumption, single supply operation (usually for battery operated circuits. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Oh that shows my stupidity in not reading datasheets. I have used the 324 and used +&-5V as bias to it just like the 741. Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Great, u have given me so many options now. I can try out either f thm! In fact i think i have a 324. il use it in place of the 741 and try eliminatin Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html if u plan to just turn on/off bulbs then use LEDs instead of bulbs as they consume higher currents. instead use bright white LEDs. they look more attr pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html As u have a single winding , why don't u check the digital part first by using only +5V?. After u have succesfully tested ur LCD, check the ADC by giv pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html I want to controll some AC devices thats why thinking of bulbs n fans n stuff. The demo will have a make or break impression on the examiner so need t Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html I am unable to get the upload file optionwwat do i do? Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Yeah i am not jumping to the relay part now. was just clearing the doubt in my mind before hand I need the opamp for the LM35 as i have only worked o Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html circuit looks good. test ur lcd part first and then go for the ADC. hope ur programmer works well.all the best pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hoping for the best... unless the programmer is set right i cant do anything on the code! Cya for now have a nice day Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html keyword for search is AtmelISP will take you to right place.. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Dear Amit, i understand your agony in case your programmer doesn't work, use a 89S52 it has ISP mode. Circuits are available free with Atmel and Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Well i finally am a bit happy today and it shows (so says my mom).Firstly, thanks to pdi33, my supply problem is sorted out! I am using a LM324 to a Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html i dont like OM Electronics they charge so high..anyways.. after reading your post first i thought which question to answer first whats the problem Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Well i prefer OM cause hes kind of reliable... n infact he is quite cheap too (atleast wrt PCBs. others were charging ~double he was!)Regarding the SM Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html forget about SMD LEDs. use the normal 3mm round ones. both consume approx. the same current and voltage.regarding the relay supply, if u are using a s pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html reference to how a sugar cube relay looks and its pin connections: search for this model on google:make: goodsky model: RW-SH-112D OR check this pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html pdi33 wrote ... If possible use sugar cube relays as they consume less current (approx. 30A per relay) and can operate from 10V to 16V.Oops..... sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html code looks good except for one smal error. The interrupt calls sensor_display which in turn calls the routines lcd delay and delay_5s. these routines pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html and sorry for the typing error (30A instead of 30mA). . thanks Shashi for t\rectifi\ying the mistake. I got amit real with that pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey pdi33,I used those SMD LEDs, they are cute lil things and the light they emit too good... and they consume musch lesser than the 2mm diodes!:D Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html That reply was for the 30A "less" current consuming relay which pdi mentioned.Of course it was a typo and he meant 30mA.And don't worry about the crys sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey shashi,Thanks Well that crystal was on the small dev board i got with the programmer. not checked the board i have made. will do it tommorow.Btw, Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html You can see the code here (Link provided by Ajay.. Thanks )http://www.paste2.org/p/18647 Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Amit Radha wrote ...Also,regarding the current drawn by it, i checked it and it was ~0.2mA which is just fine... but to be on the safer side incase of sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Shashi,Am facing a problem regarding the HIH 4000. I am getting varying voltages on different days (Dint try it with those soultions u mentioned) Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hey pdi33,Well i did get a bit worried when i saw 30A. But its oki Il incorporate the changes u mentioned, infact i think il change the register bank Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Had made another mistake, i just noticed, the order of popping from stack was wrong Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Amit Radha wrote ...Used this method because the formula for the humidity sensor was complicated, but then just realised today that the formula is fla sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks alot! The formula works perfectly now Did i read it wrong!!! i better check it out now! Thanks for the info regarding the fuse and resist Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html not sure as i do not use the common assembly compiler but i think u should try adding the directive DB at the start of each line and try compiling ite pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html And as far as the pushing and popping is concerned, u were NOT wrong buddy! that order is the exact way first in last out. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Oops... forgot that every new line under the same label must start with the DB directive! And teh comma also is not supposed to be there... just check Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Well yeah my instructions were right but the comments i put was wrong Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html you can find the ascii for degree in LCD datasheet. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Ajay, Found it there, but i am cinfused. There are 2 tables: Correspondence between Character Codes and Character Patterns (ROM Code: A00) Acco Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Ajay, Shashi, pdi33, Chiru and ShyamThanks to all of you!!! My code worked today (not flawlessly though!) I could display the temperature successf Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Btw, Ajay, i couldnt get the code for degree symbol. I used 0B0h from the table 2 of the datasheet. and it displayed hyphen '-' So pls tell me how to Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html in datasheet two tables are given one for 5x7 and other for 5x10 i think.according to font type you initialized your LCD look into that table. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html well gud to know that ur code works.... i am not that gud in asm... still i can guide u thru the steps...once u have finished with the other shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html Oki il try it again. I have brought al my stuff home so i can work over the week end and try finishing off as much as possible. Il look into the table Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Well thats not the end of my worries. Got stuck up again. My interrupt doesnt seem to be working. I have connected a button b/w INT0 and GND. During t Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html The LJMP you used in the ISR is a 3-byte instruction,whereas you've reserved only 2 bytes for it.Start your main from 06H and check again. sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hi shashi, Thanks it worked. I started from 07h Also made another change. CODE:LCD_INTR        BIT 00h Instead of EQU.now I am Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html This is my latest corrected code.Unable to display anything on line 2 of LCD even though i am using 0C0h command function.. Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html This is my latest corrected code.http://paste2.org/p/18990Unable to display anything on line 2 of LCD even though i am using 0C0h command function.. Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html use busy flag of LCD instead of using delay. second line will work Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Oh oki... well i really dint under that concept and i had read somewhere that using delay is safer and more reliable than using the busy flag oki il Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Try putting a 2ms delay between 'Enable' high and low.Also try increasing the other delay. sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html well busy flag is safer..just change the content of lcd_delay with busy flagso nothing will change.. just the code in lcd_delay subroutine. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html it is always recommended to check busy flag!!!...sometimes for th eease of programming we ignore it...if u want to ignore it then do as sashijoseph s shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html Oh oki. God knows where did i read that using delay is better than delay flag check!!! Or else i would have used the busy flag only. K il try that out Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html I made this change CODE:
lcddelay:
        SETB P0.7
        CLR RS
      & Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html I think you should have done tests on your LCD first.. or you can do it now.One more thing is there in my mind.. i think your LCD is not getting initi Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Ajay, How am i supposed to do that? I checked it for a simple message display and it work so i assumed it is fine.But i dint know i need to check f Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, use and amend this routine to check ur LCD. It is for 16X2 in 8 bit mode. ; LCD Example Program; Works with P1 as data port, R/W connected Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Chiru,Thanks so much for making this code. Helped me to understand some stuff... but i am unable to follow parts of it. Its so nice of you to take Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html hello bro! was not available for some time as net was down for a few days. well, glad to see that u have indeed made some progress. anyways, ur proble pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey pdi33!!!Back after a long time!!! And you solved my problem in a jiffy!!!! Thanks a million bro!!! So that means i can remove all those push and p Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html i don't think u will face any lag problems .as for the 7805, don't worry, it will heat up a bit as the power dissipated is high. as i mentioned earlie pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html try not to read all the sensors in one routine. try the following logic:ch-no: equ 31htemperature_data: equ 51h ; (uses locations 51 pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html hey pdi33,Well I am using a 500mA adapter so i dont think there is any danger of drawing excess current. Still, il check the entire setup in college a Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html u r right. i missed the mov ch-no,a part . anyways, the important part is that u got the idea. .well if u are using only four sensors then and the pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html hey pdi33,I tried using ur loginc to extend the code. Made a few changes to it and tried implementing it. Basically i thought, il read all the sensors Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html hey pdi33,I tried using ur loginc to extend the code. Made a few changes to it and tried implementing it. Basically i thought, il read all the sensors Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html make the following changes:1. change the follwing jump CJNE R1, #04h, adc_main ;Check for chanel no. not exceeding 7 to Cjne r1,#04h,adc_ret pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html hint:say u want to output the status of 3rd bit of register 'ch-no' tp port p2.1 use the following instructions:clr cmov acc,ch-nomov c,acc+3mov p2.1, pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hi PDI.......about the changes you suggested.The Ascii_Result has been commented out if you observe closely.The 1st change you suggested is a good one sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey pdi33!Thanks for correcting me. Now i know what i was doing wrong! My system was in an infinite loop of reading the ADC only and that is why it wa Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html oops thats the error message screen shot.codev0.3.zip is my code i used to get the o/p today and i cut short the LUT to have it working... Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html hmmm, i don't see any way to reduce ur code further except that u can remove the push and pops in interrupt service routine as they are unneccessary n pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Yup ASM51 is neat.Use Keil's IDE to create the source only. sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks il check them out... I tried Ride, it came on the disk i got with my programmer but that was really wierd! It gave me errors in the include Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Sorry i forgot to ask,Now since i can remove the push and pop instructions, the only thing left in the isr is CODE:SETB LCD_INTR So shall i put it a Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Yeah....that will save you a ljmp. sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks shashi, Pls have a look at my last post on page 22 also. Aso regarding ASM51. I have it but unable to asemble. when i enter the file path and n Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Amit Radha wrote ...Hey thanks il check them out... I tried Ride, it came on the disk i got with my programmer but that was really wierd! It gave me e sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html sashijoseph wrote ...With a 0.3V difference and a slope of 30mv/%RH you still have around 10 steps to use for your go-nogo logic.That should be enough Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html well, this is not the right time to suggest, but i feel seeing ur project, the ideal choice of microcontroller would have been the ATmega series AVRs. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Well even i was told the same. But dint want to get into learning the nitty grities of a new controller. With the 8051 i have some good knowledge so i Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html hey amit,u are a quick learner,i still remember your first topic on using keil.....nobody catches up so fast good going buddy shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Shyam!Well, i had a very good teacher who taught me 8085,86,8051 and VHDL. So i have always had interest in processors and controllers. I have Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Good luck Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Chiru,Tested with 3 sensors today. Working just fine... had a mnd boggling time trying to figure out why the pins for the actuators were always Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Well, demonstrating a humidity sensor, other than the chemical process, is difficult. Otherwise, what I could have done, put a commercial hygrometer b Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html what is the problem with the method suggested using different chemicals? . i have tried it before on a commercal humidity sensor (which gives a 0~1 pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Chiru,Thanks for the idea... but frankly its too expensive for my final yr project i think I am planning to use a metal tube spray with water s Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html and, about the current being used by 1M pot,well the max. current take by it ould still be in microamperes so do not wory about the current consumptio pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey pdi33,Well there is no problem regarding the solutions u mentioned. I ntried NaCl, it was taking time to increase, and it only reached 60%. But th Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html let me tell u why i insisted on the idea;actually, when we (our company first designed a RH indicator, we too faced the same problem but in a differen pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html about the moisture sensor, i am sorry but i have little idea about the principle of operation of such sensors. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Amit Radha wrote ...Regarding the soil moisture sensor, il try this new method. But where do i read the o/p voltage? across the 2 sensor probes and th sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey pdi, That was really informative thanks a lot Your idea was the best way we had but since we were told that the sensor could get damaged we thou Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi,Back after a long time. Sorry for not logging in, been busy with other college work!I have almost completed my entire system. Just interfacing it w Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html shortage of ram can cause a problem like this and there is hardly any solution to this problem. Try some of these...Change controller with better ram. Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html But if u check my code, i am hardly using my RAM! especally location 60h to 80h used for the actuator status is not touched at all, and some part of i Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hey sorted out that problem I had made a collosal blunder. Realised it when i tried debugging the code and used the logic analyser feature..I had put Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Just when things seemed to be going in the right direction, I am back to square one!!!My humidity sensor HIH4000 seems to be in a foul mood all of a s Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Keep the sensor in a charged silica gel jar over-night to remove moisture (contact chemistry lab technicion for the silica). Moisture trapped in the h Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Chiru, Back after long? How are u?Il try it out with the silica gel. Just dint strike that it moisture could be the problem even though i knew its Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Chiru,The Silica gel dint seem to work I bought 2 fresh sachets of silica gel and put them in a small air tight container over the weekend. Toda Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html hi amit,the output of your relay port pin being 2~3V is perfectly o.k.. Actually, the reason of this is that the ports of 89c51 (except P0 which is op pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Oh ok. yeah i can try using PNPs.well i have done all the wiring now... and it all seems to be working right and when i checked them individually they Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit.What value base resistors have you used for the relay drivers? sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Shashijoseph,I am using 10K resistors to the base of the transistors. But I sorted out that relay problem today. There was a small communication g Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, received your mail, sorry for the delay About your problem, remove the sensor and put a 10K pot and generate the same voltages, as would be Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Chiru,Pls dont apologise!!! Well my uC ckt n code is fine. All my sensors work fine and for the voltage o/p of the sensor (when checked with multim Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html try checking one thing,connect ony the supply to the sensor and check the output voltage with a multimeter with the sensor kept hanging in free air.. pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hey pdi,well i tried checking the sensor by separately connecting it to supply and on different days the o/p voltage was different (and close to the m Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html wel, it may seem odd, but i have seen humidity readings change (very drastically) of a humidity sensor if it is brought in contact with hot air especi pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html Hmm that is a possibility, but why should the humidity change by just bringing my hand close to the sensor? And i was using an AC cooling fan (.1A) to Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hi Amit, I went through all the findings you have stated about the humidity sensor, and strongly feel that the sensor is fine . Mind it, this partic Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html well you will get appreciation for your work as you have done everything yourself. You should not worry. Your hard work will show up Best of luck!E Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Chiru,Nice to hear from you after a long time.But tell me one thing, why do u feel the sensor is fine? I feel it has gone bad because the o/p immd Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Ajay, Thanks alot for ur support al this while. I will certainly upload the entire material once am done with the exam. Without this forum i reall Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Well this album link has some of the snapshots of the so far completed prject of mine. Pls do have a look when u get the time and post ur comments. Il Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Awesome Work!!!!!Must have this on forum so others can comment too Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Ajay Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html gr8 work ... keep it up! shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html I am Impressed by your neat and systematic work. Shailesh NAYAK<nayaktel@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks a lot A lot of credit for it reaching this stage goes to all of u at this forum and my lab foreman, Mr Ramesh Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Really well done..... If I were to do it,the actual hardware would get 'embedded' somewhere beneath a dense foliage of unmanageable wires. sashijoseph<sashijoseph@nospam.com> http://www.8051projects.net/forum-t5757.html you deserve it Ajay<contact@nospam.com> http://www.8051projects.net/forum-t5757.html Thanks Sashijoseph, Tried as much to keep it as neat as possible! After all the evaluators who come are more impressed by looks rather than the work! Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Good job done, Amit, congrats to you and your classmates. These hard work will payoff in your future. Good luck. Chiru<ckarmakar@nospam.com> http://www.8051projects.net/forum-t5757.html Hey thanks a lot Had my 1st demo today. ppl liked the idea and we were able to answer al qestions thrown at us, but we were told our "product" is a f Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Also, we were told we have no fault detection system so if any of our sensors go bad the system should have a detection and intimation system in place Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html o.k. o.k.. well, the inpectors were right to some extent, but what do they expect from u? A full fledged marketable product?. well,they should know th pdi33<islurpundalik@nospam.com> http://www.8051projects.net/forum-t5757.html welll... u shud not be disheartened...but what the inspector told u was an important aspect of your project..projects in BE shud not only be prove o shyam<shyam@nospam.com> http://www.8051projects.net/forum-t5757.html aprt from honeywell is there any gud "humidity sensor" available in the market??m working on greenbee pro.. m nt getting rquired o/p voltag in soil mo priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html Hi priyaWow nice to see this thread again after long. But I was hoping that I have asked the silliest of questions here at this thread that any one wh Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html thanks amit.... i went thru this thread... n it seems u hv really worked hard on this pro yaar...... it reflects in ur marks .. n if u say ur quests priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html Hey Priya,Firstly thanks a ton for the appreciation Now I remember you, you had posted your queries in the project page right? Do try out the circu Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html thanks fr ur suggestions amit.....m using the same AT89S52 uC... abt HIH4000...i'll ask my H.O.D if they cud provide me any help...... m tyring fr ano priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html n yes ... i checked rob faludi's soil moisture circuit.... the same ws used by u..i'll be trying it on monday... priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html i tested the temperature sensor ckt used in GREEN BEE project.. it had lm35 as temp sensor and lm324 to amplify the o/p.. the voltage dint rise if i priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html n one more thing... m nt getting ny gud ADC tutorial... can ny one send me the link fr tht?? priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html Read the mahesh wankhde turorial. I think he has explained why an amp is useful. You will be able to show better variations for starters. Also ease in Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html Could you tell me what th eissue is that you are facing with the circuit? Well, you can use the LM35 directly with the ADC just like its done in Mazid Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html hii amit..yes... thr is an error in lm324 pin connection.. the vcc and grnd wr swapped... i connected the ckt correctly... bt initially m getting .28 priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html n regarding ADC tutorial... thanks a lot fr suggesting..u used IC 4083 -a schmitt trigger nand gate for generating clock fr ADC.. nt getting this IC.. priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html moisture sensor is working perfectly ...getting the desired results... thanks fr ur valuable suggestions.. abt humidity.. hv dropped it.. nt using priya m<priya_manke@nospam.com> http://www.8051projects.net/forum-t5757.html Oh thats good and bad news! Are they happy with just 3 parameters then? Well in that case you could try modifying it and trying some more ad-ons to th Amit Radha<amit.radhakrishnan@nospam.com> http://www.8051projects.net/forum-t5757.html