Differences

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--- flash_the_atmega [2013/10/03 15:00] – created breaker27
+++ flash_the_atmega [2023/03/01 19:40] (current) – [Using flash scripts] breaker27
@@ Line 1: / Line 1: @@
-===== Get the firmware =====
+====== Get the firmware ======
-You can either take a pre-built firmware package from [[http://www.smarthomatic.org/builds/builds.html]] or build your own firmware. If you take the prebuilt package, extract it and continue with "Flashing the controller".
+You can either take a pre-built firmware package from [[http://www.smarthomatic.org/builds/builds.html]] or [[build your own firmware|build your own firmware]]. If you take the prebuilt package, extract it to a directory of your choice.
-===== Build your own firmware =====
+====== Three different storage areas ======
-Get a copy of the project, if you haven't already. When you're running Debian (or another Linux) this will do the job: <code>git clone git://github.com/breaker27/smarthomatic</code>
+Every microcontroller has three parts that can be flashed (written):
-Go into the base station firmware directory, build the firmware
-<code>pi@ninjablock ~/test $ cd smarthomatic/firmware/shc_basestation/
+  * Three **fuse bytes** contains microcontroller specific configuration bits. These should only be set once.
-pi@ninjablock ~/test/smarthomatic/firmware/shc_basestation $ make
+  * The **flash memory** contains the firmware. It can be overwritten about 10.000 times.
-avr-gcc -c -gdwarf-2 -DF_CPU=20000000UL -DUART_BAUD_RATE=19200UL -DUART_RX=1UL -Os -mmcu=atmega328 -I.  -fdata-sections -ffunction-sections -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -Wundef -std=c99  -Wa,-adhlns=build/
+  * 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/shc_basestation.elf > build/shc_basestation.lss
-avr-nm -n build/shc_basestation.elf > build/shc_basestation.sym
-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     bss     dec     hex filename
-      33     739   18036    4674 build/shc_basestation.elf
+===== Using a make rule =====
-pi@ninjablock ~/test/smarthomatic/firmware/shc_basestation $
+If you build your binaries by yourself with "make", your fuse settings should be available as files **lfuse.bin**, **hfuse.bin** and **efuse.bin** in the bin subdirectory **of the device you want to flash**. You can write these fuses with:
+<code>
+make program_fuses
 </code>
-===== 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:
+<code>
+avrdude -p ATMEGA328P -U lfuse:w:0x??:m
+</code>
+(replace ?? by the hex value for the needed fuse settings and use "lfuse", "hfuse" or "efuse" accordingly).
+===== 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:
+<code>
+avrdude: verification error, first mismatch at byte 0x0000
+xfc != 0x04
+avrdude: verification error; content mismatch
+</code>
+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
+===== 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:
+<code>
+make program
+</code>
+===== Calling avrdude directly =====
+If you want to call avrdude by hand you can flash everything with:
 <code>
-pi@ninjablock ~/test/smarthomatic/firmware/shc_basestation $ avrdude -P /dev/ttyACM0 -c STK500 -p m328p -U flash:w:bin/ohc_basestation.hex -U lfuse:w:0xf7:m -U hfuse:w:0xd1:m -U efuse:w:0x07:m
+avrdude -p m328p -U flash:w:shc_basestation.hex -U eeprom:w:shc_basestation.e2p:r -U lfuse:w:lfuse.bin:r -U hfuse:w:hfuse.bin:r -U efuse:w:efuse.bin:r
 </code>
+(leave one part "-U ..." out to flash only a part).