Hi I am unable to upload sketch to Atmel mega1284p using a mcp2221 usb to uart converter IC.
I have a simple code prints “message received” It works to program the Mega1284p using arduino nano as ISP. But not using the MCP2221 over usb. I took a long time and eventually errors out. I tried pressing reset button on ATMega while uploading, I tried swapping TX and RX. I double checked COM port. Please help.
See pics for setup and connections. My setup is similar to the attached Schematic.