Differences

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--- reprap:anet:anet_mainboard_overclocking [2018/01/04 15:41] – [Crystal selection and replacement] gmarsh23
+++ reprap:anet:anet_mainboard_overclocking [2018/01/09 04:05] – [Updating the bootloader] gmarsh23
@@ Line 100: / Line 100: @@
 === Downloading and compiling Optiboot ===
+**If you're using a 24MHz crystal, just copy this paste and save it as a .hex file:** https://pastebin.com/Tv1EHPmc
 You'll need to download and compile Optiboot first. More information can be found on the Optiboot github page: https://github.com/Optiboot/optiboot/wiki/CompilingOptiboot
@@ Line 105: / Line 107: @@
 Use the following options to compile it for the Anet V1.0 board. Change the "24000000" value to the frequency of the crystal you're using in Hz - don't forget the L on the end.
-  make AVR_FREQ=24000000L BAUD_RATE=57600 LED=A4 atmega1284p UART=0
+  make AVR_FREQ=24000000L BAUD_RATE=57600 LED=A4 UART=0 atmega1284p
 Save the .hex file for later.
@@ Line 117: / Line 119: @@
 === Flashing new firmware ===
-Use AVRDUDE:
+Use AVRDUDE to set the fuse/lockbit values on the processor, then program in the new bootloader:
+  avrdude -p atmega1284p -c <your programmer> -U hfuse:w:0xDE:m lfuse:w:0xf7:m efuse:w:0xfc:m lock:w:0x2f:m
+  avrdude -p atmega1284p -c <your programmer> -U flash:w:optiboot_atmega1284p.hex
-  avrdude -p atmega1284p -c <your programer> -U flash:w:optiboot_new.hex
+The fuse values given move the bootloader start address to 0xFE00/0x1FC00 (word/byte) which frees up 3K of application space from the bootloader section. The lock bits prevent the bootloader from overwriting itself and bricking the board, if you send in a code image which is big enough to expand into the bootloader space.
 Once the board is programmed, connect the board to your PC via its USB connection, and attempt to "ping" the new bootloader with the following avrdude command. Change "COM1" to the serial port corresponding to the printer on your computer.