Trouble getting Picstep to run...HELP Please

[barmybovine]

Hey all

OK I have built 4 picstep boards and a 4 axis interface. I am trying to verify that the pic steps work on their own before hooking up the interface. I cannot get it to work

I currently have a a cable setup to test them as shown in this link

http://pminmo.com/troubleshoot.htm

I have it wired as a bipolar. With the enable and dir pins both going permanently to ground and a N.O. switch on the step pin. I have an external +5v supply to the pics and about 30V top the motors. I have tried several of the boards and have the same symptoms on each board. I am using Pic 16f628A i/p chips which I believe should work ....correct?

The symptoms are as follows when programmed with the 20 Mhz codes using the default settings when programming the chips ie. HS oscillator WDT,PWRT and BODEN enabled and everything else disabled
it programs and verifies fine.

When I fire up my power supplies I get a quick vibration from the motors then nothing switch the step seems to do nothing also the motors are not locked in position as I can easily rotate the shaft. As I turn off the 5volt supply I get the same motor vibration. I have also tried pulling the Xtal and caps and programming the 4Mhz codes both have the same symptoms. Just for a laugh I tried programming the pic using ExtClk as the oscillator and this makes the motors go crazy ....randomly vibrating and spinning with the step pin seemingly having no effect on the motors conditions.

Like I say I get the same symptoms on multiple boards so dont think its a problem with the PCB's themselves. Any input would be GREAT....I have been building my machine for 6 months and was REALLY hoping to get it moving under NC control this weekend.

Thanks guys

Scott

[pminmo]

which version of the picstep? did you select current limiting resistors to match your motor requirements?

[barmybovine]

Thanks for the reply

Version 4.0. I am going to try interface to your 4 axis bard once I get the pisteps working

I have 2 X 7.15K resistors installed in each board to run my 2.8A motors

Thanks
Scott

[pminmo]

Did you realize the orientation of the 10 pin connector on the V4 is 180 degrees different than my boards?

[barmybovine]

yes i made sure to match up the pins between boards. I am not using an IDC cable. I am using a 5 pin connector to wire in enable\dir\step\GNd and +5V

At the moment I am trying to get the pics running without the interface and just using the same 5 pin cable with an IDC header plugged in one end so I could short enable and dir to GND whilst having a N.O. switch wired between the step pin and GND


Thanks

[pminmo]

What is your power supplies current capability?
It sounds like you don't have the motors enabled, since your motor can freely turn with power on. Any pictures ? maybe there is a clue that would be visable.

[barmybovine]

I am using a bench supply that can do about 8 amps @30V I dont have pics.
My camera is at work but I could run and grab it if needed. I should take enable LO ...correct?

Thanks

[southernexplore]

He may need to enable the pic. That was my problem when I first started.
Tommy C.

[pminmo]

Tommy, not sure what you mean? The Brake/Enable on pin 1? Does you have to set a 628A's clock source when you program it? I'm not a PIC kind of guy........Not yet anyway.

[barmybovine]

same here o the pics. I checked into that and by default as you load the HEX code into ICPROG it selects HS as the oscillator. I believe that to be an external clock above 4Mhz . I have tried running at 4mhz with the 4mhz code and the Xtals removed but still the same. I get the motors to vibrate and turn but in a random fashion when I select ExtClk as my oscillator during pic programming. When programmed this way , if I pull the enable pin from my connector the motor stops all together and can be rotated once I reconnect the enable line the motor starts to freak out again so I believe I have enabled the motor by taking the enable line LO

I feel like it is something simple stopping them I just cant figure it out.

Thanks guys

[pminmo]

Right off the top of my head, I don't have any suggestions. Maybe somebody that uses a PICstep.

[southernexplore]

When I started I did not know anything about any of this either. Through trial and error I was able to get mine going and they run great now. I did let some smoke out a few times but when I learn the hard way I usually do not forget.

My boards would not run until I ran a jumper on the 4 axis BOB to pin 1 on the 10 pin connector. I believe it has to be pulled low to run, if my memory serves me correctly. Also be sure and use the std firmware because the hi torque version did not work for me.

Tommy C.