Working bootloader hex on 18f2550

**f_lez** · - 29th January 2008, 13:40

Ok I was looking on the web for working bootloaders for the 18f2550, I found lots of hex and tried them all until I found one that seems to do the required business....

I put it here for anyone who wants etc
(http://www.yorktraders.org/working2550.hex)

I stuffed it in with winpic800 and a willem, mounted pic on a homemade PCB board with leds on all ports, connected it, and rb0 / rb1 leds flash.....

First they flash together for a few seconds, then change to alternate flashing

like its waiting for something, or maybe thats all it does?

I connected it to the PC with a usb cable, and windows saw an unknown device, downloading the microchip 'pic184550 family drivers' it now shows up in device manager when I plug it into windows.

Once connected the leds flash all the time....(together then alternate)

So, where do I go from here to getting an 'hello world' or night rider LED demo into it ?

Maybe this hex is not a boot loader after all but a flashing led demo!

Seems I have my hardware problems all sorted, just dont know the next step

skimask · - 29th January 2008, 18:22

Originally Posted by f_lez

Ok I was looking on the web for working bootloaders for the 18f2550, I found lots of hex and tried them all until I found one that seems to do the required business....
I stuffed it in with winpic800 and a willem, mounted pic on a homemade PCB board with leds on all ports, connected it, and rb0 / rb1 leds flash.....
First they flash together for a few seconds, then change to alternate flashing
like its waiting for something, or maybe thats all it does?
I connected it to the PC with a usb cable, and windows saw an unknown device, downloading the microchip 'pic184550 family drivers' it now shows up in device manager when I plug it into windows.
Once connected the leds flash all the time....(together then alternate)
So, where do I go from here to getting an 'hello world' or night rider LED demo into it ?
Maybe this hex is not a boot loader after all but a flashing led demo!
Seems I have my hardware problems all sorted, just dont know the next step

Nothing to work with here... No backlink to the source site for the hex and any hints/descriptions of what the hex might do, no pictures of the schematics, LEDs, etc.
From what I read, it sounds like what you've got is exactly what you said...some pretty flashing/blinking lights.

**f_lez** · - 30th January 2008, 00:23

well as it shows up in windows as a 'pic18f4550 family'' i'd presume its the original or compatible microchip bootloader.

schemetic is simple, leds on every port.....

Problem is most diagrams I find for it are for the 4550, so where do I connect a switch to bootload,do I need a switch to bootload?

Why is everything bootloader for the 4550?

seems anyone wanting to play with 2550's are getting the short end of the stick.....

how do I generate basic that compatible with a bootloader etc.

All this and other questions answered on the next episode of.........

**Bruce** · - 6th February 2008, 16:53

I modified the Microchip C18 firmware for the USB loader a while back to work with the 18F2550. I have attached it here with a simple PBP code example.

Comments are in the PBP code for LED & switch connections. I know it works. I'm using it. If you have problems check your connections.

I won't have time to offer tech support on using the USB loader, re-compile it for another clock speed, USB PIC, etc, etc, so enjoy, and hopefully you won't have any problems.

You might want to download the docs for Microchips USB demo board. This explains a lot about the loader & circuits required, and how the C18 USB loader firmware works.

If anyone wants the modified C18 USB loader files let me know. Note you will need the C18 "C" compiler if you want to make changes.