Howdy folks! I’m trying to get a 1284p to load sketches from an SD Card (AVR_BOOT) and am stuck. I would really appreciate any help you could offer.
1284p is wired on breadboard as shown in attachment 1284pAVRBOOT.jpg. It is very similar to the MIGHTY and MightyCore circuits.
The primary exception is the addition of the Adafruit Micro SD Breakout board, and LED’s on pins 1, 2, 20 (physical numbers). Bootloading is done through an Arduino Mega (on an Uno, device always came up with zeros - strange). Also used an OSEPP FTDI for serial and sketch uploading.
I can load MightyCore using the following settings: ATmega1284, External 16 MHz, BOD 2.7, LTO Disabled, Variant 1284P, Standard Pinout, UART0, Arduino as ISP.
Sketches uploaded via FTDI can blink the LED’s and read files from the SD Card.
Next, I burn the AVR_BOOT bootloader. Settings: ATmega1284/P 16MHz External, SD CS Pin 4, BOD 2.7, Pinout Standard, Processor ATmega1284P, Arduino as ISP.
Burn succeeds just fine. No errors.
Sketch on the SD Card is very basic. digitalWrite to the the three LED pins (0, 1, 14) with various delays. Have a few Serial.println’s. Converted it to FIRMWARE.BIN using:
avr-objcopy -I ihex -O binary sketch.hex FIRMWARE.BIN
When I power it up through the MEGA, almost nothing happens. SD activity light blinks once.
Disconnect the Mega completely and power it up through FTDI is slightly more dramatic:
LED’s on pins 0 & 1 blink 5 times times dimly. SD activity light blinks once.
Nothing sent via serial.
Any ideas about what is going on? SD Card reading works fine prior to AVR_BOOT install, so why isn’t it doing much when the power is connected? It’s dimly blinking some LED’s - what does that mean? Everything works perfectly fine when I use a 328p - figured an upgrade to a more awesome processor would be easy… I’ve switched breadboards several times - I’m pretty sure this is a good one.
Many thanks for your help!