flash_the_atmega
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flash_the_atmega [2013/10/03 15:00] – created breaker27 | flash_the_atmega [2013/11/17 14:06] – [Strange avrdude error messages] breaker27 | ||
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- | ===== Get the firmware ===== | + | ====== Get the firmware |
- | You can either take a pre-built firmware package from [[http:// | + | You can either take a pre-built firmware package from [[http:// |
- | ===== Build your own firmware | + | ====== Three different storage areas ====== |
- | Get a copy of the project, if you haven' | + | Every microcontroller has three parts that can be flashed |
- | Go into the base station firmware directory, build the firmware | + | |
- | < | + | * Three **fuse bytes** contains microcontroller specific configuration bits. These should only be set once. |
- | pi@ninjablock ~/ | + | * The **flash memory** contains the firmware. |
- | avr-gcc -c -gdwarf-2 -DF_CPU=20000000UL -DUART_BAUD_RATE=19200UL -DUART_RX=1UL -Os -mmcu=atmega328 -I. | + | * The **EEPROM memory** contains (firmware) configuration data. It is also written to by the device in normal operation. It can we overwritten about 100.000 times. |
- | [...] | + | |
- | avr-objdump -h -S build/ | + | |
- | avr-nm -n build/ | + | |
- | Fuses: | + | {{danger.gif}} **In general, it's a good idea to only flash what you need to, because of the limited amount of possible write cycles.** |
- | LFUSE = 0xF7 | + | |
- | HFUSE = 0xD1 | + | |
- | EFUSE = 0x07 | + | |
- | Image size: | + | ====== Programming fuses ====== |
- | text data | + | |
- | | + | ===== Using a make rule ===== |
- | pi@ninjablock ~/ | + | |
+ | If you build your binaries by yourself with " | ||
+ | |||
+ | < | ||
+ | make program_fuses | ||
</ | </ | ||
- | ===== Flashing the controller | + | Be sure about the fuse settings you want to write in your microcontroller. With wrong fuse settings, your microcontroller might not be accessible anymore! |
+ | |||
+ | ===== Calling avrdude directly ===== | ||
+ | |||
+ | If you are creating a new or modified SHC device, you may want to write other than the default fuses. You can do so with: | ||
+ | |||
+ | < | ||
+ | avrdude -p ATMEGA328P -U lfuse: | ||
+ | </ | ||
+ | |||
+ | (replace ?? by the hex value for the needed fuse settings and use " | ||
+ | |||
+ | ===== Strange avrdude error messages ===== | ||
+ | |||
+ | Some fuses only use a part of their bits. If you set such a fuse, avrdude may complain at verification that it read out another value than it wrote. | ||
+ | |||
+ | Writing the EFuse of the ATMega168 or 328 returns a value of only the last 3 bits (upper 5 unused), so a value of xxxxxyyy is read out as 00000yyy. Example: | ||
+ | |||
+ | < | ||
+ | avrdude: verification error, first mismatch at byte 0x0000 | ||
+ | 0xfc != 0x04 | ||
+ | avrdude: verification error; content mismatch | ||
+ | </ | ||
+ | |||
+ | Don't worry. The warning is only returned because avrdude does not know that the upper 5 bits are always 1 (as per spec). | ||
+ | |||
+ | ====== Flashing the firmware / eeprom ====== | ||
+ | |||
+ | ===== Using flash scripts ===== | ||
+ | |||
+ | After setting up avrdude, you can flash the firmware by calling the flash scripts | ||
+ | |||
+ | * **flash.cmd** / **flash.sh** for flashing firmware, eeprom and fuses | ||
+ | * **flash_firmware.cmd** / **flash_firmware.sh** for flashing only the firmware | ||
+ | * FIXME: The Linux scripts do not exist yet. | ||
+ | |||
+ | ===== Using a make rule ===== | ||
+ | |||
+ | If you have the source code on your machine, you can flash the firmware with the following command from the firmware subdirectory: | ||
+ | |||
+ | < | ||
+ | make program | ||
+ | </ | ||
+ | |||
+ | ===== Calling avrdude directly | ||
+ | |||
+ | If you want to call avrdude by hand you can flash everything with: | ||
< | < | ||
- | pi@ninjablock ~/ | + | avrdude -p m328p -U flash:w:shc_basestation.hex -U eeprom: |
</ | </ | ||
+ | (leave one part "-U ..." out to flash only a part). |
flash_the_atmega.txt · Last modified: 2023/03/01 19:40 by breaker27