AVR boot code how to
Due to a failure with the electrical system in the car last year, we had to replace the AVR, the new chip was missing a boot loader so this page is about what I did to program the AVR.
The main source of information about the boot loader is here : GenBoard/Firmware/BootLoader. The command line for the most recent avrdude is a bit different to the advice given there, but it's easy to figure out (don't use -c stk200, use -c bsd). Use my command line for the actual upload of the boot loader, see below.
- Download avrdude [here].
- Download the [Boot loader hex file].
- You'll need to request boot loader hex file from the shop for your serialnr (submit your serialnr and original orderID or at least name of customer who purchased assembled controller or board). Without the proper serialnr the software will not work properly.
First I followed the advice about the fuses and then went on to program the AVR boot code.
- In avrdude for windows (winAVR) you need to install giveIO in the c:/winavr/bin/install_giveio.bat
- Burning the fuses use this code:
Note that lock=3C is recommended (not lock=3F) to allow bootloader-upgrade later.
\n
D:\VEMS>avrdude -c bsd -p m128 -U flash:w:main.hex
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e9702
avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "main.hex"
avrdude: input file main.hex auto detected as Intel Hex
avrdude: writing flash (131072 bytes):
Writing | ################################################## | 100% 50.61s
avrdude: 131072 bytes of flash written
avrdude: verifying flash memory against main.hex:
avrdude: load data flash data from input file main.hex:
avrdude: input file main.hex auto detected as Intel Hex
avrdude: input file main.hex contains 131072 bytes
avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 48.36s
avrdude: verifying ...
avrdude: 131072 bytes of flash verified
avrdude: safemode: Fuses OK
avrdude done. Thank you.
This cable is to be used togheter with the "-C bsd" command in AVRDUDE
| AVR pin command | ISP header # | Parallel port pin | Notes |
| AVR /RESET | 5 | 7 | Yellow |
| AVR SCK (clock input) | 3 | 8 | Black |
| AVR PDI (RXD) (instruction in) | 4 | 9 | Red |
| AVR PDO (TXD) (data out) | 1 | 10 | Orange |
| Signal Ground | 6 | 18 | Brown |
Correct pins from the schematics AVR pin 2 = RXD/PDI -> ISP header Pin4, AVR Pin3 = TXD/PDO -> ISP header pin 1
This is what it looked like:
After the bootloader is uploaded
- upload firmware with VemsTune (Tools / Firmware upload)
- see File / firmware info
- check your serialnr and firmware version