Pic to Pic Firmware upgrade

[rjones2102]

Hi all,

Has anyone know if it is possible to write a program in PBP that will read firmware from a serial interface and then program another Pic with the firmware?

Ultimately I want to upgrade firmware wirelessly (RF and GPRS modem) so Pic to Pic will get me moving in the right direction.

If it looks too hard, how do people who use Pics do downloadable firmware upgrades? It might give me a starting point to think laterally for a solution.

Thanks

Rich

[mister_e]

Bootloader should work. But this may require a two-way communication.

[BobP]

Hi,

Have used several telecommunication products that upgraded it's firmware by radio. It’s not as straightforward as it seems.

It should not be too difficult to transmit the firmware to the receiving GSM as internal error correction should keep errors to a minimum. But a RF link to the reciving PIC may give problems? The bigger the firmware the harder it will be. External memory will most likely be required. The biggest problem is getting an accurate copy of the firmware over to the receiving PIC. One company sends the firmware twice and compared it for errors. The firmware must be stored and checked before loading into the PIC's own memory. Remember any corruption of the transmitted firmware when loaded and run could ‘lock’ the receiving PIC. Necessitating a visit to do a hardwire re-programming.

One system I had to use solved all these problems but forgot to allow for the phone connection 'dropping' in mid transfer. The result was a trip on site and reseting and reloading software.

As has been said previously a modified version of a bootloader followed by a reset should do the job.

Bob

[rjones2102]

Thanks guys,

OK, I already figured some external memory might be necessary to fit the code into prior to the actual reprogramming of remote Pic.

The GPRS modem will have a TCP/IP stack so the file will be FTPed across air. So, that will deal with the data integrity of the firmware that reaches the actual hardwired network.

When sending to the ultimate destination transmitting it twice and doing a compare sounds a good idea. It might end up more than twice but as long as it doesn't loose integrity that will be fine.

Using a bootloader should eliminate the problem of failed firmware upgrade requiring a trip to 'shop' as the code will not be loaded unless it has been received error free providing the bootloader has the smarts.

I guess what I need is bootloader code for a Pic. I am not clever enough (yet!) to write it so has anyone got any starting points for me? I bet someone has written one even if not in the PBP world. Hummm, a wider google search needed I think. I will post anything I find as this thread could be interesting as it develops.

Thanks

Rich

[Ioannis]

Please note that if you are going to use a bootloader, your precious hex code will be free for anyone to copy it! There can not be bootloader AND code protection at the same time!

Ioannis

[Jumper]

It works great with a bootloader and codeprotection together. It is even possible to encrypt the hexfile into jibberish on your PC and later letting the bootloader de-jibberish it while flashing it. This way the code is safe all the way (depending on what encryption used) and if you use a PIC that is safer (i.e 18 series).

With codeprotection you can not read or write with an external programmer but the software inside the PIC (loader) can always erase and write in the codespace.

This can be done PIC to PIC or I2C or serial or what ever kind of way....

/me