do these things come set from the factory requiring an external crystal or something?
Quotedo these things come set from the factory requiring an external crystal or something?The normal "burn bootloader" process first programs the fuses and lock bits, then loads the bootloader, and then changes the lock bits again; a three step process. For most types of Arduino, the initial programming of the fuse bits will set the chip configuration to REQUIRE an external crystal; if you don't have a crystal, the subsequent steps will fail. To program a chip using the internal clock without an external crystal, you'll need a special BOARDS.TXT entry that has different fuse byte values!
So first question, do these things come set from the factory requiring an external crystal or something?
Quote from: steven6282 on Jul 28, 2012, 05:19 amSo first question, do these things come set from the factory requiring an external crystal or something?No. Fresh from the factory they use the internal 8 MHz oscillator and the /8 prescale so they run at 1 MHz. Many people sell 386P chip pre-loaded with the Arduino UNO bootloader. Those chips need a 16 MHz oscillator.The good news is that you can force an external oscillator into the crystal pin to allow programming. Luckily for you, Adafruit Industries has made a modified version of ArduinoISP that outputs a 8 MHz clock on Pin 9 that you can feed into your 386P: https://github.com/adafruit/ArduinoISP
I've tried that arduinoisp sketch that you linked as well now (which doesn't have very good instructions by the way, says it has 8mhz output on pin 9 but no instructions on how to use it. Does it plug into one of the external crystal oscillator pins on the 328 or somewhere else?).
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