Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: mohamed on January 29, 2008, 04:07:21 AM

Title: $50 robot, wiring problem?
Post by: mohamed on January 29, 2008, 04:07:21 AM
now i finished my connection..and i connect the battery but the LED didnt light up and when i connect the battery directly to the LED it light up ...does that means that there is something wrong to my connection although i checked with the multimeter every wire when the multimeter make sound that means the wire is connected
Ps: when the battery is connected the regulator heat up but not to high is this normal.

thanks


admin edit: changed the subject from "Can someone help plz!!" to something informative . . .
Title: Re: Can someone help plz!!
Post by: SmAsH on January 29, 2008, 04:11:06 AM
i seriously think a connection is broken :D i think the regulator is fine.
Title: Re: Can someone help plz!!
Post by: mohamed on January 29, 2008, 04:32:58 AM
So the LED has to light when the battery is added?
Title: Re: Can someone help plz!!
Post by: javafiend on January 29, 2008, 07:21:47 AM
I had the same problem in this post (http://www.societyofrobots.com/robotforum/index.php?topic=2966.0) and this is what was finally brought to light:

if i remember the schematic the led only lights up when the mcu pin it is attatched to pulls low. So it shouldnt light up reliably before its programmed
yep yep yep!
the LED is connected to the +5V regulator's output pin and PIND4. the user controls the LED. using LED_on() or LED_off(). if the robot is programmed correctly (using Admin's default code), the LED should be ON.
Title: Re: Can someone help plz!!
Post by: Trumpkin on January 29, 2008, 09:33:11 AM
I'm having the same problem, I programmed it correctly and it still won't light. the servos work tho. ???
Title: Re: Can someone help plz!!
Post by: airman00 on January 29, 2008, 06:22:27 PM
I'm having the same problem, I programmed it correctly and it still won't light. the servos work tho. ???

did you put the LED in correctly?
Title: Re: Can someone help plz!!
Post by: HDL_CinC_Dragon on January 29, 2008, 06:25:26 PM
I have everything set up correctly also and am running the stock code but still no dice. I never figured it out... so I put it in a different LED setup that didnt require the use of the MCU. Just a resistor from the main battery terminal
Title: Re: Can someone help plz!!
Post by: paulstreats on January 29, 2008, 06:31:01 PM
Quote
I'm having the same problem, I programmed it correctly and it still won't light. the servos work tho.

So you really dont have a problem other than the way the led is set up or it is an unusual defective one


Quote
I have everything set up correctly also and am running the stock code but still no dice. I never figured it out... so I put it in a different LED setup that didnt require the use of the MCU. Just a resistor from the main battery terminal

I think this is a good idea and maybe an improvement to the design. It lets people know if the circuit is working before they plug the mcu in (if they dont have a multimeter)

(also if i remember from when you posted this problem hdl, you had the led polarised wrongly :))
Title: Re: Can someone help plz!!
Post by: HDL_CinC_Dragon on January 29, 2008, 06:55:55 PM
(also if i remember from when you posted this problem hdl, you had the led polarised wrongly :))
*Breaks out DMM and tests LEDs polarity*
*Checks and Rechecks schematic*
*Checks LED again*
*Checks schematic again*
*Deletes entire Sharp IR Robot folder from AVR studio*
*Re-downloads the Sharp IR Robot code from the site*
*Remakes the Sharp IR Robot project*
*Unzips all the zipped stuff into the recreated Sharp IR Robot folder*
*Closes project in AVR Studio and reopens it via the Project Wizard*
*Re-enters the make file into the make file option thingy*
*Unplugs all peripherals from robot board*
*Builds .c file*
*Programs the MCU*
^LED doesnt turn on^
*Grabs another tiny LED that I have in my stash*
*Reverses the polarity compared to the soldered LED*
*Curses to self incessantly as the reversed polarity LED lights up*

DARN YOU PAUL!


Time to rework that part of my circuit >_<
Thanks paul :)
Title: Re: Can someone help plz!!
Post by: paulstreats on January 29, 2008, 08:33:04 PM
you could have probably done it in code if the led is connected up the wrong way around just by changing the 0 to a 1 (or using led_off function)
 ;D
Title: Re: $50 robot, wiring problem?
Post by: Admin on January 31, 2008, 09:45:44 PM
I'm convinced the LED for the $50 robot is low quality and just breaks . . . I put on two, and within days both fried . . . there is an old post from a year ago when I tried to debug it . . . try a different LED and see what happens.

Quote
when the battery is connected the regulator heat up but not to high is this normal.
check for something shorting . . . it shouldn't even be slightly warm . . .
Title: Re: $50 robot, wiring problem?
Post by: Trumpkin on February 01, 2008, 09:27:21 AM
The led lights up when I give power to it directly tho. I did take out the Atmega 8 before I tried this.