Discussion in "Project Help" started by    kks    Mar 1, 2018.
Sat Mar 10 2018, 10:00 AM
#21


>I said it before, i have changed the project to secure car access system
Actually you said you were "thinking" of changing to a secure car access system.

>Goodness so now i need a limit switch too
No, you will need two limit switches.

>now i am stick with led.
You could have two LEDs, one for motor forward, one for back.

You unlock the car with an RFID key.
How do you lock it ?


ExperimenterUK


Yeah well our professor told us to do the car one because its less common. I fo have two led's, green and red. Just a question, is it necessary to apply resistor to the microcontroller for led. Cause it requires 330ohm and i have a 10k one. If i will apply that then the light will probably be very dim.


[ Edited Sun Mar 11 2018, 03:35 PM ]
Sun Mar 11 2018, 01:49 AM
#22
>Cause it requires 33ohm and i have a 10k one.
>If i will apply that then the light will probably be very dim.
Yes it will be very dim.
The suggested value is probably 330 ohms.
Anything from 220 to 1K should do. ( 1/4 watt)
Resistors can often be salvaged from old equipment.

You did not say how the door is locked.
You could swipe to lock, and swipe again to unlock, but it needs more code.
Sun Mar 11 2018, 07:47 AM
#23


Resistors can often be salvaged from old equipment.

You did not say how the door is locked.
You could swipe to lock, and swipe again to unlock, but it needs more code.

ExperimenterUK


Yeah i do have an old circuit of some speaker lying around, but i think the resistor are of higher ohms than 1k. I don't even have a voltmeter to check them.
As for the door locking again, you just have to swipe one to unlock and it will be locked again after some delay. Isn't that usually how all smart doors works. You do get a appropriate amount of time to pass. Ofcourse i could have added an sensor to keep the door opened as long as you are near to door, so that the door doesn't close on you. But it's too late now.
UPDATE: I did the connections and joined the negative of the leds to the resistor that i pried out of some old circuit whose resistance i am not aware of. I suppose it's more than 1k so i joined both the negatives to the same resistor. The positive is connected to the microcontroller for input. I did the same in proteus and it works fine there. But only my green led is lightning up in real. The red led doesn't light up for some reason. The soldering part is proper so i can't think of a reason why its not working. Does red led require higher voltage?


[ Edited Sun Mar 11 2018, 03:39 PM ]
Sun Mar 11 2018, 07:53 PM
#24
>As for the door locking again, you just have to swipe one to unlock
> and it will be locked again after some delay.
>Isn't that usually how all smart doors works.

Is this "secure car access system" to lock/unlock a single car
or a car park ?

> I did the connections and joined the negative of the leds
>to the resistor that i pried out of some old
>circuit whose resistance i am not aware of.

You can't just guess, assume and hope with electronics, things get damaged.
I'm not surprised is does not work.
Proteus is much more forgiving than the real thing.

Resistors have codes on them. Usually coloured bands
that tell you the resistance.

Your professor may want you to do the car project,
but you can't complete this project without the right parts.


[ Edited Sun Mar 11 2018, 07:56 PM ]
Sun Mar 11 2018, 08:10 PM
#25
It's Society car access system, where only the cars belonging to the members of the society will have access to its parking area. That way no outsider can come in and park their car.
I didn't knew that the color bands indicate resistance. I broke quite a few resistors today trying to get it from the circuit.
The reason i went ahead with the connection is because i thought a high resistance unlike low can't do much damage to anything.
Actually in Proteus, the led does get dim when apply high resistance. My green led is glowing alright but the red one is really very dim, almost unnoticeable.
I just need a low resistor now. Have to complete this project by Tuesday.
Sun Mar 11 2018, 10:47 PM
#26
http://www.resistorguide.com/resistor-color-code/

>The soldering part is proper so i can't think of a reason why its not working.
>Does red led require higher voltage?

There is a slight difference, but not significant.
More likely the red LED is the wrong way round.
Try the red LED in place of the green and try it both ways round.
It should light up.
If not, it is faulty.
Let me know the result, meanwhile I will look at the code.
....
I have sent a PM.



[ Edited Sun Mar 11 2018, 11:38 PM ]
Mon Mar 12 2018, 01:11 AM
#27
It isn't faulty, but very dim. I tried it both way round, it does light up but you have to be in a dark room to actually see it. The green ones working fine either way, its not the brightest but it can be seen. BTW thanks for the code.
Mon Mar 12 2018, 05:07 AM
#28


It isn't faulty, but very dim. I tried it both way round, it does light up but you have to be in a dark room to actually see it.

kks


If it is much dimmer than the green one, it is probably faulty.
Mon Mar 12 2018, 06:54 PM
#29
As i said, it just needed it's own resistor. It's working perfectly now. Thanks a lot for all your help. It's really hard to find people like you who spend time to answer your doubts everyday. Seriously without you i wouldn't have been able to complete this project!
Wed Mar 14 2018, 10:46 PM
#30


Thanks a lot for all your help. It's really hard to find people like you who spend time to answer your doubts everyday. Seriously without you i wouldn't have been able to complete this project!

kks


Thanks for that.
I hope your project goes well.

Get Social

Information

Powered by e107 Forum System

Conversation

ExperimenterUK
Sat Oct 12 2019, 10:23 PM
Log in.. then post your code in the 8051 forum
Sat Oct 12 2019, 10:18 AM
Bhadra Sajikumar
i am doing a countdown timer with 8051 for my project, unfortunately our professor had to take a leave of absence before he could teach us most of it.. can someone explain the .asm code of it for me?
Mon Sep 23 2019, 07:37 AM
Nathaniel
I am doing a project for my schools wireless security system with cameras,sensors and spot lights using 8051 micro controller, could you help me out with the design and its source code.
Wed Sep 18 2019, 08:48 PM
Caryn Kover
Thank you for your time,
ExperimenterUK
Mon Aug 05 2019, 07:09 PM
@Ismail ..post in forum, give details
Mon Aug 05 2019, 04:33 PM
Ismail balghmi
Hello. Please I won't download
ExperimenterUK
Wed Jul 24 2019, 12:47 AM
@BUSTER123 Please post in the forum
Tue Jul 23 2019, 06:13 PM
BUSTER123
hello! newbie here. i am kind of a guy who hates using ready - made existing libraries, so this helped a lot as i was trying to control and write to a character lcd display. however, i can't figure out how to set the cursor position. for example, i want to set it to the 5th column in the first row, so position 5. so according to the table, i am sending 10000101 on the 8 data lines of the lcd (register select pulled low). the cursor does not move there however. and i cant move the cursor left or right too. is it something wrong that i am doing? thank you.
ExperimenterUK
Thu Jul 11 2019, 07:55 PM
@ramos https://www.theengineeringprojects.com/2017/09/l298-motor-driver-library-proteus.html
ExperimenterUK
Thu Jul 11 2019, 07:44 PM
@praveen123. Can you give a link to the project ?

Downloads

Comments

Casmir
Wed Nov 13 2019, 06:25 AM
DeepakBGattani
Mon Nov 11 2019, 01:31 PM
Jeanbusatta
Sun Nov 10 2019, 04:42 AM
mdayaz
Sat Nov 09 2019, 03:41 PM
baoyen123
Fri Nov 08 2019, 10:06 AM
xiwang
Fri Nov 08 2019, 07:28 AM
ilylily07
Tue Oct 15 2019, 04:32 PM
hientran123
Tue Oct 15 2019, 02:27 AM

Online

Guests: 50, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 38103
Newest member: Casmir
Forum Activity
Jeanbusatta Avatar
Posted By Jeanbusatta
Sun Nov 10 2019, 04:43 AM
ty, really needed it
ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Oct 22 2019, 05:18 AM
wimac Avatar
Posted By wimac
Mon Oct 21 2019, 09:18 AM
I’ve been following this thread and looking at the...
s_dinesh40@yahoo.com Avatar
Posted By [email protected]
Sun Oct 20 2019, 03:09 PM
s_dinesh40@yahoo.com Avatar
Posted By [email protected]
Sun Oct 20 2019, 03:02 PM
sir, when i on display ,sometime 3rd display is no...
s_dinesh40@yahoo.com Avatar
Posted By [email protected]
Sun Oct 20 2019, 02:53 PM
sir, when i on display ,sometime 3rd display is no...
ExperimenterUK Avatar
Posted By ExperimenterUK
Sun Oct 20 2019, 12:21 AM
Your code seems okay on my simulationTry my code o...
s_dinesh40@yahoo.com Avatar
Posted By [email protected]
Sat Oct 19 2019, 07:13 PM
please find video attachment. 3rd & 4th displa...
s_dinesh40@yahoo.com Avatar
Posted By [email protected]
Sat Oct 19 2019, 07:05 PM
sir, 3rd and 4th dot matrix display flickering, ...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Oct 18 2019, 09:18 PM
Hopefully you understand some of the program.Which...