[megeshg]

Hi All...

I am currently trying to replicate the POSIX design linistepper. I am using the transistor aligned design posted on the lini website and i am having no joy.

I first built the circuit and found that the one transistor would remain on constantly and begin to smoke. I though that the pic maybe stuck and thus replaced the sense resistors and all the transistors. Programmed a new pic with v2 asm file and powered up again.

This time i get nothing, no smoke, nothing, the motor is not even energized, i can turn the motor with my fingers. there is voltage at the transistor but it doesnt seem to move onto the motor coils. I have also now changed the BC337's and still nothing.

What would be the route to troubleshoot this design? How would i test to ensure that the pic is behaving has needed? Any help would be greatly appreciated.

[megeshg]

Any help on the matter would be greatly appreciated!

[James Newton]

Measure the voltages on the output of the PIC pins. See if they are correct as you step the input. You should see the voltages change in a stepping pattern. If not, the PIC isn't running. If you do, then the problem is in the transistors.

[megeshg]

Thanks so much James!!! you pointed me in the right direction and i cant believe what a face palm of note i deserve!

After all the testing i found that everything was working fine! turns out that the electronics store supplied me with 1K sense resistors instead of 1 ohm!!! man was i pissed, but i am partly to blame should have measured when i saw the writing was not clear on the package!

New sense resisitors in and working like a charm! now to mount heat sink and clean up wiring then i have a working motor driver!!!

Big thanks to Roman for the open source design, yourself for the help and answering of questions and POSIX for his interpretation of the one sided PCB!

[James Newton]

LOL. So glad you got it working.

[megeshg]

Yeah also quite happy, thanks again for all ur help