ideas for programming multiple pics

nmeyer · Joined: 09 Jul 2004 Posts: 70

Hello,
I have a ciruit board that has four identical circuits on it, each containing a PIC16F72 (all contain identical code) part. I am looking for ideas on how I can program all 4 parts through one connector (ie db9) so that users of this product can update the firmware in the feild. I need some thing that is simple to do so anyone with limited technical ability can do it. All ideas would be appreciated.

MGP · Joined: 11 Sep 2003 Posts: 57

16F72's can't write their own memory (Flash) can they? That would rule out some type of bootloader.

If not, your only choice will be some sort of ICSP connection. That would probably require common signals for VPP/MCLR, VDD, VSS, PGC, PGD and a select signal for each PIC in your circuit. That would take 9 connections. You'd also need some logic on your board to hold each of the non-programming PICs in a RESET state while the other is programmed.

To make it easy for the end user you are most likely going to have to come up with your own programming hardware and software to make it a "one click" operation. You might be able to get the source code to an existing programmer and modify it to select each PIC individually and program/verify them one at a time. Not impossible, but not trivial either...