Sensors

you deserve it

Good job done, Amit, congrats to you and your classmates.
These hard work will payoff in your future. Good luck.
:bye

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 failure and "ppl wont buy it" because we dont have a facility for the user to enter the threshold levels into the uC and they are pre-set. Thus it is not a flexible system.
It sounds absurd cos, firstly, we are not designing a "product", its just a prototype of a concept! Also, the Embedded system prof who asked this had this concept fixed in his mind that thresholds must be in registers only and not in code ROM.
I tried explaining that if we use the RAM the user wil have to enter the 10 - 12 threshold levels everytime the system is reset or turned off. to which he said, store it in the rom and then put it in registers!!!! how absurd can one get!!!

Tomoro i have my demo and presentation for 70marks. pls tel me if there is an answer to this question! i am perplexed...

Looking for some expert advice on handling this kinda wierd questions!
:-|

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! that is a valid point... dunno wat to do bout that

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 that there are some limitations as far as a student knowledge is concerned. So don't worry. The extent of work u have independently acheived is far from ordinary and definetely not substandard and i can assure u only a few students can even think of attempting such a project independently.

As for the threshold levels jus tell them that u can store it in the eeprom if it is connected externally via I2C interface (a 24c02 would be sufficient in ur case to store 10-12 parameters).as far as flexibility si concerned, u can just convince them that adding a few keys to the uC and addition of some code can make the user input the 10-12 parameters . The procedure to write code is lengthy ad may take a lot of time so better try it if u are interested after ur submission. As for the ROM is concerned it is easy to store and fetch data from the ROM (using the movc instruction). but it is very difficult to change that data from program memory( it is possible in a rare few derivatives of 8051 and is called in circuit programming ICP).i hope that is explanation enough for ur queries.

and yes, i forgot to comment that ur project (the image ) is praiseworthy and extremely neat (almost professional) ) I wouldn't be surprised if ur inspectors would give ur team some brownie points on that one . good luck.

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 of concept like...
u shud accept any suggestions offered with open heart..

but i do beleive he must have been impressed by ur work... though he didnt say it aloud!

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 moisture sensor.. cn u pls suggest me ny circuit.. !!!! or is thr ny sensor available whc cn be used directly...??

thanks...

Hi priya
Wow 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 who reads it will get all the answers!
Regarding the humidity sensor, that is only one i could find in the market (well that is quite difficult to get too). Where are you located? I could give you teh address if ur in bangalore. I think some one had suggested alternate sensors in this thread during the initial days, pls do check if you can find it.

Coming the soil moisture sensor, the o/p voltage need'nt be fixed, you can modify the threshold values depending on the o/ps you are getting.
The o/p depends on a number of factors, like the type/ thickness and length of the probes, distance between them, the type of soil, depth at which they are placed etc. So choose the most optimum combination. Also let me warn you that the soil mositure sensor is the most dicey-est sensor in the entire setup. But it does work and I had got the circuit from a site by a person by the name Rob Faludi. He is using thi scircuit for a commercial product (so he claims)

Good luck hope this helped you and do ping me in case you need any more help.

ps: is the code working?

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 r silly then mine wud be sillier than u..

i live in indore (m.p)... honeywell is nt availble hr.. another sensor is available.. bt its nt tht sesnsitive... right nw m concentrating on the 3 sensors (temp, moisture n light intensity).. regarding soil moisture.. yeh u told me abt the factors on whc the o/p depends.. (guess u remeber it ) ...hv u used the same ckt whc is in ur report??

abt the code... hv nt used it still..

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 circuit. That is the one we have used, (unless I am forgetting, i shall check up with my project batchmates and let you know) also try varying the pot to get a good value of gain. Do one thing, just bring both probes in contact and see what is the o/p voltage, that should tell you if it is working. Try searching Rob Faludi's blog, you'l get the exact circuit.

Also, you could try adding something else to the set up,another sensor perhaps. Which uC are you using? If you have more ports you could really improve upon this. We were planning for making it a multi controller set up and sms based notification! Huge dreams but less time.

Also regarding the HIH4000, you could ask your college "(if they are supportive) to contact the components dealer of your college if he can source it for you. It is very much possible and you can also get free samples.

Good luck.