Working bootloader hex on 18f2550

[bcd]

Cool, thanks Bruce.

Downloading it now. I have an older version that I got when installing the PICDEM FS Usb board.

Interesting its the HID bootloader, but your version appears as a custom USB device that I can program with the PICDEM FS Demo application, rather than an HID device. Maybe this newer version is a built different.


bill.

[bcd]

Hi Bruce,

Having some issues - Sent you a Message - you might need to log into your User Panel to see it - can't see the Private Message option on the forum anymore..

Might be MPLAB crosseye-ness though !

bill

[bcd]

I am a very happy chappie !

I managed to recompile the bootloader to use alternative LED pins. One thing to be aware of is that there are now two bootloader codebases that Microchip provide. One is the HID bootloader, the other is one that will work with the MPUSB application.

I tried the HID bootloader, but got some weird results, so instead modified the MPUSB bootloader which uses the custom Microchip driver. This allows me to continue to use the PICDEM FS Demo Board application to bootload my code.

All good ! Also learned more about MPLAB and C coding than I think I ever wanted to know...

bill.

[mister_e]

Grrrrrrrrreat! It's always good to have another tool in the toolbox huh?

Out of curiosity... what kind of problem you got with HIDBootloader?

[bcd]

Hi Steve,

I think it was more the PC application would have some issues resetting the PIC after uploading.

I'll have a try again when I get home as I also locked up the USB ports on my laptop by accidentally connecting the PicKit2 backwards on the ICSP header....

Luckily they came good after a reboot and I then reflashed the board with the MCPUSB bootloader and we were away !

I'd actually prefer to use the HID bootloader, so I will see if I can get it to work and let you all know.

Man, the more I play with this USB stuff the more I love it !!!

bill.

[bcd]

Just doing a bit of digging in MPLAB at luchtime and I think I know why it was not working.

It seems the HID bootloader is a lot bigger than the MCHPUSB one. In MPLAB it uses 2040 bytes of program memory, compared with the 980 used by the MSCHUSB one.

In my PBP code I had this :

DEFINE RESET_ORG 800h

statement to jump over the end of the bootloader, but for the HID version I would need to make that RESET_ORG 1000h.

Like I said, I will try it when I get home as suddenly things make a lot more sense - I remember I was having issues with the program not working after I had bootloaded it, and then the bootloader failing - which I put down to me locking up the USB ports (which I also did).

Like I said, I love it, but it needs a lot of brain time !!

bill.

[bcd]

Updating the PBP code with

DEFINE RESET_ORG 1000h ' For Microchip USB Bootloader
DEFINE INTERRUPT_ORG 1008h ' For Microchip USB Bootloader

Fixed the issue so I can now use the HID bootloader, which has the source for the Bootloader PC app.

With the second DEFINE I am not sure if I require it, but I have seen it mentioned in some posts and the Microchip docs actually mention that the Interrupt vectors are moved. It also says that the High and Low priority are on two separate locations, but my code seems to work and its late.

Tomorrow I will investigate further..

Till then Happy Pic'n !

bill

[Bruce]

All you need to make the new HID loader work with PBP is DEFINE RESET_ORG 1000h.

If you're using both high-pri & low-pri interrupts, then just use the interrupt DEFINEs.

Example:

DEFINE INTHAND High-Pri
DEFINE INTLHAND Low-Pri

PBP will automatically take care of it for you with ORG RESET_ORG + 8 for the high priority
jump, and ORG RESET_ORG + 18h for the low priority jump.

At 0x1008 PBP inserts GOTO High-Pri, and at 0x1018 GOTO Low-Pri.

If you're not using interrupts all you need is the DEFINE RESET_ORG 1000h.

[bcd]

Bruce,

I have DT_Int running, so will these commands still be needed ? Not sure if it adds these automagically.

bill.