Bootloaders

[AtomSoft]

I know you can use boot loaders to load/upgrade a new program into the pic from like USART/USB but can you load it off External EEPROM chip or SD card? Like would it be possible instead of it checking taking the new program in automatically i can hold a button down on starup and have it load the new data from a sd card and then program itself and afterward still use data off the SD to load info.

I was thinking of testing on a PIC18F452 or PIC18F4620

 

[Mike - K8LH]

A bootloader could be programmed to pull the hex data from almost anywhere you like...

Mike

 

[picbits]

As above - just have the bootloader software in your PIC which pulls the data from the SD card and copies it into its program memory.

 

[AtomSoft]

awsome. ok cool. I think using something like this would make upgrading a product easy and as simple as drag n drop hex on card and place card connected to PIC and done!

 

[Someone Electro]

Yes a bootloader can take the data from nearly anything from a COM port to a SD card to the internet.

I saw the propeller video demo board has a nice bootloder. It displays all the programs found on a SD card on a TV or monitor connected to the video port and you can select what program to run using the buttons.

 

[AtomSoft]

Cool! I was just woundering. I understand the concept somewhat of what needs to be done but. No one ever mentioned how to make the HEX to upload. Like once you setup the boot-loader how do you create the hex file to upload to it? Is it just a normal program like hex created by MPLAB just without the bootloader? Like if i made a bootloader and then have it on the pic.

Would i just make the program or main code next like normal with no bootloader code and just send it to it via bootloader?

 

[futz]

Cool! I was just woundering. I understand the concept somewhat of what needs to be done but. No one ever mentioned how to make the HEX to upload. Like once you setup the boot-loader how do you create the hex file to upload to it? Is it just a normal program like hex created by MPLAB just without the bootloader? Like if i made a bootloader and then have it on the pic.

Would i just make the program or main code next like normal with no bootloader code and just send it to it via bootloader?

It's just the normal hex file. It would be really dumb to require a special, different hex file just for bootloaders. It's just software.

Try a ready made bootloader for a while before writing your own. You'll understand better what you need then.

 

[AtomSoft]

ok so i load a ready made bootloader then i write my own normal code and upload the normal code to the pic via bootloader?

Can you recommend some bootloader i would prefer in C please. Whether its in CSS, C18 or any other C (not Mikro tho) im sure i can port over.

 

[futz]

ok so i load a ready made bootloader then i write my own normal code and upload the normal code to the pic via bootloader?

Can you recommend some bootloader i would prefer in C please. Whether its in CSS, C18 or any other C (not Mikro tho) im sure i can port over.

Doesn't Microchip have one? Thought I heard of one from them. I could be wrong. Anyway, Google for it.

 

[3v0]

The USB bitwacker uses one as does the PICkit2.

 

[AtomSoft]

I was afraid of the USB one because i might get lost in the code since its mixed with so many things to run the USB. So i wanted to start with a non-usb one. This way i can learn how it works better.

Futz. You are right "**broken link removed**" but its in ASM. And as you may think its like 3 pages long which would be a pain to convert to C; but since i seem to have no choice i guess i will.

 

[Nigel Goodwin]

Have a look here

Microchip PIC micros and C - source and sample code

I've not used the 18F one, but I've used the 16F version over the years, and found it excellent (and requires no extra pins to be used).

 

[AtomSoft]

thx i downloaded it and will play now! i have like 5-6 18F1320s on hand