I need some insight on troubleshooting what might be wrong with my project.
With the set up that I have there is 2 GM7 motors that the micro is driving controlled by a BS2 @ 9v and pololu micro @ 9v. Things were working fine for a few days…until…I put my coverings on my robot and one channel of the micro just stopped working.
I have the motors set for 2 and 3. 2 works fine however 3 just stopped functioning out of the clear blue sky. No voltage is supplied on pins 8 and 9 and there should be.
I verified all of my code and connections and everything on that end is fine. Any additional help would be great.
If things were working for a few days and then the problem occurred, something probably broke. Since the malfunction happened when you applied the covering to your robot, it’s possible that something got shorted or disconnected at that time.
Also, what is your logic supply? If you’re using the 5V from the Stamp, you might get some trouble there as you add additional components (and load) to that line.
I just realized that pins 8 and 9 are motor 2, which you said works. Are you sure you’re sending the right command and checking the corresponding pins?
Pins 8 and 9 are where I am expecting voltage to run my second motor and there is none. I think that your right about the shorting out thing. It ran flawlessly on the breadboard.I am bypassing the bs2 voltage regulator and using my own to supply both the stamp through vcc and the micro. Do you think that is not enough? should I add seperate supplies? One of the quirks that I noticed before was the micro kept resetting. The stamp would still be supplying serial data, however, the reset line to the micro would drop below 5v until the stamp was reset. This would happen when the motors speed would increase. Incidentally, the micro is as cool as a cucumber… not that much heat is being generated.
After a while, I checked my grounds and that seemed to help. Then this happens !!! What do you think?
I was just noting the inconsistency of your post. Pins 8 and 9 will correspond to even-numbered motor numbers, so they won’t do anything if you send commands for motor 3. It sounds like motor 2 (not 3) is the one that is no longer working.
As for the reset problems, they are indicative of noise in your system. Make sure you have capacitors across the motor leads, and make sure your power supply is clean. Do you have access to an oscilloscope to look at your power lines?
OK, I see. Sorry for the inconsistency.
I have the controller programmed to send serial commands to motor numbers 2 and 3. What you are saying is that pins 8 and 9 are the output for motor motor 3 and it sounded like I was talking about motor 2. OK, I get it. Sorry about that. Thank you for your patience. As for the scope, I don’t have access to one as of yet, however, I will be getting one soon.
One question that I do have is…
In your oppinion, could anything in my setup from what I have posted cause the micro to be permanently damaged on pins 8 and 9? Thats what I am realy concerned about. I have been very careful about ESD aswell. Origionally everything worked fine on the breadboard with a clean 5v supply from my board of education from parallax.
After creating a perfboard circuit and having this problem surface, I went back to the breadboard to recreate my origional proto-setup. The problem is still there! Do you think I should just go ahead and get another one?
Maybe try another perfboard from scratch? With my circuit design I used the schematic from the Parallax BOE for my logic supply. Any help would be greatly appreciated. Your posts thus far have been very helpful.
The worst things you can do are apply power backwards, short the outputs, or apply too much voltage. An ESD zap could also damage either one of the chips. From your descriptions, I suspect that your motor controller is damaged. You can return your unit to get a repair or replacement at a reduced price; please contact us directly (by phone or email) for details.
Thanks for your help. That did the trick. A new one was all that I needed.
You folks are so quick with your help and delivery !!