3 AXIS PIC STEP

[wtxrcdog]

Hello I have built Alexander's 3 axis pic step controller and current limiter. i am having a heck of a time trying to program the 12c508a pics. they always have some sort of an error. I do not know what to set the different fuses to before programming. I loaded the program into ME Labs and ran it on the simulator and I had to turn off the wdt to make it run. I am a newby to electronics and pic programming.
Thanks Bruce

[jans123]

Alexander's 3 axis pic step controller??? Never heard about it. Got a link?
/jan

[wtxrcdog]

Hello It is at www.pminmo.com
It is a cool little driver board but I can't get the pics programmed properly

[Ozheat]

The config bits are already set in hex code. Anyway here they are.
Oscillator - IntOsc
Watchdog Timer - Off
Code Protect - Off
Master Clear Enable - Internal

Calibration Memory value is left at whatever factory set. Do not change.

[wtxrcdog]

Hello No matter what I try I have not been able to program these pics with out an error. I am just about to give up on this project. I spent a lot of time building the hardware part of it to be held up on the programming. Since these pics are one time programming I think I will wait until I learn more about programming them and try to write my own program for them. [some day]
Bruce

[neilw20]

Microchip recommend PIC12F508 to replace PIC12C508a.
You will get bored with erasing this device before you can't use it any more.
OTP's are meant to be in the museum now.

[wtxrcdog]

I will try them thanks for the tip
Bruce

[Ozheat]

Just a wild guess.....as I just tried the code and it worked ok.
The error you are probally experiencing is that you are overwriting the factory calibration memory value.
The best thing to do is read the blank 12x508 and note the calibration value and then make sure that value is set when writing to the chip.
If the value is incorrect the internal oscillator will either be out of spec or not work at all.

I used MPLAB and ICD 2 programmer, I also programmed a 12c508 with pic16pro and a kit42 programmer. Both work OK.

[wtxrcdog]

Hello
I have just been using the hex file provided. I have not changed the code in any way. Actually I don't know how to change the code. I have used a JDM serial programmer and a QL- 200 programmer with several different software setups.
Bruce

[Ozheat]

The calibration value is not set in the hex file, it is preprogrammed in the 12c508's memory. As I said read the blank chip and note the calibration value, make sure the value is the same before writing. You can overwrite the value with 0x00 rendering otps useless, The last chip that I programmed had a value of 0xC24 for calibration.

If you read the programmed chip and compare the hex are they the same? What is the value of the calibration bits? When do you get the error?

[wtxrcdog]

Ok When I read the pic there is a oc74 at the end of the list. Is this the code that needs to be inserted into the hex? If so where do I insert it at?
Thanks Bruce

[Ozheat]

ok. 0x0C74 is the calibration value for THAT chip and was obiviously what was factory set.
So it rules out the cal val not being set, you failed to answer the last part of the question above. When do you get the error or does the chip fail to run?
You can also put leds on the 4 output pins so you know when each output is High or Low state, easier to see what is happening to the PIC.