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- If you are using the 6MHz on-board clock, set C0 to CLK6
- If you are driving another board from USB power, increase power level appropriately (device should always be set as bus powered)
- Depending on USB chip version, you may also need to: disable USB remote wakeup, disable plug and play.
- If you wish, you may program the remaining CBUS pins as required for your applications (including C0, if you are using a crystal oscillator)
Before you start making changes, download the configuration from the USB chip. You will need to save your configuration before the software will allow you to flash the FTDI chip (it has a funky separate edit mode for making changes, and program mode for setting them).
Step 3: Program microcontroller
Use avrdude under GNU/Linux to program the microcontroller with your firmware. Be aware that you need to reprogram the fuses to make the chip compatible with your clocking scheme.
To use the 6MHz oscillator from the USB chip, CKSEL3..0 should be set to 0000. SUT may be conservatively set to 10. The system clock prescaler should be disabled. This gives the fuse settings of: 11100000. To set this from AVRDude, run:
avrdude -c dasa -p m48 -P /dev/ttyUSB0 -U lfuse:w:0xE0:m
NOTE: Be very careful programming the fuse bits. If you program the fuse bits incorrectly, your Mini will turn into a brick.
The next step is to upload the firmware.
Step 4: Test the Mini from a terminal program
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