Flashing sketch over serial port to a bare 328p.

Projects Programming
5

alas no luck.

I reburned the bootloader using SPI and then tried to use the uart to burn a sketch.

the Uno has an autoreset circuit and reset on the target board is pulled up with a 10k resistor. probably unnecessary given that the Uno itself is pulled up by 10kOhm.

for sure I am using an 8MHz bootloader.

after reburning the bootloader I still can't burn via uart. the wiring is simple:

  1. remove 328p chip from Uno
  2. reset -> reset
  3. 5v -> Vin
  4. GND->GND
  5. RX->RX
  6. TX->TX

there is one non 5v tolerant component on the board but it does not get powered up until told by the sketch. so not a problem at the moment (and burning that is the least of my concerns).

the verbose response from avrdude is unhelpful:

        Using Port                    : usb
         Using Programmer              : stk500v2
avrdude: usbdev_open(): did not find any USB device "usb" (0x03eb:0x2104)

avrdude done.  Thank you.

An error occurred while uploading the sketch

any suggestions please?

thanks again
justin