I have an Arduino Pro Mini that I use with a USBASP to program. These are actually a clone Pro Mini and a clone USBASP I'm using.

With this configuration, is it possible for me to access the serial port on the Arduino, through the USBASP, using the IDE serial terminal? If so, this would alleviate another connection to the computer for debugging. How to do this?

2 Answers 2


From the USBASP documentation:

  • Planned: serial interface to target (e.g. for debugging).

..and further on..

Firmware: The firmware dosn't support USB Suspend Mode. A bidirectional serial interface to slave exists in hardware but the firmware doesn't support it yet.

Keep in mind, that's from 2011, so it's possible someone has built an updated version of the firmware with that functionality. You'd have to do some searching (I'm not familiar with any such firmware).

For now, your best bet is just getting a TTL serial-USB converter (they're cheap) and connecting it directly to the Pro Mini.


I've searched in google and found a project in Atmel Community that supports serial with USBasp here. They called it USBASP-tty. I've not tested it yet but i think it will work. There are basically three requirements for it :

  1. On the PC side, it uses a different software to capture the serial data from the usbasp.
  2. It needs the conventionally bought usbasp programmers to have the two serial connections (image: PDO and PD1 connected with the ISCP header) to work. If those aren't already made, you have to rewire the pins. Normally these connections aren't made and the ICSP pins are connected to ground.
  3. The firmware of your usbasp programmer must be updated to the provided firmware using another programmer.

enter image description here

  • Note that the LC Tech USBasp follows the schematic exactly and has the pins connected, but the Baite EvUSBasp does not. Aug 22, 2016 at 18:02

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