Looking for a good USB Bootloader

Tom-H-PIC · Joined: 08 Sep 2003 Posts: 105 Location: New Castle, DE

I'm looking for a USB bootloader for the 18F25xx and 18F45xx, that use the CDC profile and no hardware grounding pins.
Would also like a PC interface.
I searched the board but if you put in "bootloader" it returns thousands of hits.
I also looked in the code library and did not find a USB bootloader full code.
Has any ported the Microchip bootloader?

Tom

dbotkin · Joined: 08 Sep 2003 Posts: 197 Location: Omaha NE USA

Did you miss ex_usb_bootloader? I'm using it... my only complaint, and a fairly minor one, is that it seems to crash occasionally. Doesn't cause any problems, you just need to do it a second time.

Pros: Simple, requires no host application -- meaning you can use a Windows PC, Linux, Mac, whatever. And it's free.

Cons: No error checking, retry or corrupted data recovery.

In its native form it does need a pushbutton or some other indication that the user wants to do an application load. You could get around that by waiting some predetermined time and sending a prompt, but of course that means your application has to wait while the bootloader decides whether it's finished waiting on the user.

If by "PC interface" you mean you want a loader app that runs on the PC, then this one isn't for you. I'm half tempted to rewrite it with Xmodem or some similar protocol, which would still allow the use of many ordinary comm programs but would provide error retry. I really don't want to have to write or maintain PC-side applications for Linux, Mac and every new flavor of Windows that wanders down the road.