PIC Development Board V2.1

andy257 · Post by **andy257** » Tue Oct 17, 2006 10:22 am

Hi All,

Beginner here having problems autodetecting my microcontroller. I am using the latest version of PPP and it detects the board fine. However when i try to detect the controller i am using i get an error saying it is not found.

I am using the PIC16F84, the strange thing is i have a PIC16F84A and it can be detected no problems.

Is this a duff chip or a common problem with the board?

Cheers

Andy

Post by **Benj** » Tue Oct 17, 2006 11:55 am

Hi Andy

Does the 16F84 still program and work if the type of controller is assigned manually in PPP. If it is not working then it would suggest a problem with the chip. Im afraid I only have 16F84A's here to test and you say they are being detected fine. Let me know how you get on.

Post by **Steve** » Wed Oct 18, 2006 8:18 am

The 16F84 does not have an inbuilt id number, so can't be identified. The 16F84a does, which is why that one is ok.

The chip should work fine. Just make sure that you specify the 16F84 in the configuration screen.

andy257 · Post by **andy257** » Wed Nov 01, 2006 11:23 am

Hi Steve,

Thanks for your help. The 16F84 does indeed program as long as it is named as the chip being used. I thought it was strange that it did not have any autodetect function. Now i know why.

I have another problem with my board. I seem to have to hold the reset button down constantly for my program to execute. If the reset is not held down the board will do nothing.

Any ideas what is wrong?

Cheers

Andy

Post by **Steve** » Wed Nov 01, 2006 2:56 pm

Hi Andy,

That seems an odd problem - has it always behaved like this, or is it a recent problem? Also, does it work ok if the parallel port cable is removed? And what about different chips (if you have access to any)?

We've not manufactured the v2 dev board for a few years now and I'm now more familiar with the improved v3 board, but I'll try to help.

What is the voltage on the MCLR pin of the 84 chip when the reset pin is pressed and when it is not pressed? And are the voltages the same when the parallel port cable is plugged in and when it is unplugged?

This might be a start to solving the problem.

andy257 · Post by **andy257** » Wed Nov 01, 2006 6:28 pm

Hi Steve,

The board works fine without the parallel cable plugged in. I dont know why i never tried this before but your analysis was correct. I do not have a multimeter at home to check the voltage levels.

I am running windows xp would that make any difference?

i am new to programming so this is my first time using the board. The only chips i have access to are the 16F84 and the 16F84A. Both work fine.

Cheers

Andy

Post by **Steve** » Thu Nov 02, 2006 9:15 am

Hi Andy,

What might be happening is that some process within Windows is taking over the LPT output once the programming of the chip has finished, and this is seting the LPT pins in such a way that prevents the PICmicro from running.

Changing the operating system may make a difference, but I wouldn't suggest it - it is a drastic move! If you can live with this problem, then I suggest you do - i.e. remove the LPT cable when you want to see the program running.

Note that the more recent USB programming board (dev board v3, or HP488-00-3) doesn't have this problem.