Setup Serial Debugging Tool


  • [x] A Serial Debugging Tool. In this guide, we will use a USB to TTL Converter. Ensure that it supports the 1500000 baudrate.
  • [x] Edge needs the Edge-IO breakout-board to support serial debugging.


Follow these steps to make the correct connections:

1) Connect Edge-IO board to Edge via the FPC connector.

2) Connect all the GPIOs, and check that the Tx / Rx Pins are connected correctly:

  • Tool Pin GND: <---> Edge IO GND
  • Tool Pin TXD: <---> Edge IO RXD
  • Tool Pin RXD: <---> Edge IO TXD

The connections should look like this:

Image of SerialConnections

3) Insert the USB-end into your Host-PC.

Setup Kermit Protocol(C-Kermit)

Install c-kermit:

$ sudo apt-get install ckermit

Add Access Permission

$ sudo usermod -a -G dialout $(whoami)

Add the following contents into ~/.kermrc to finish the setup:

set line /dev/ttyUSB0
set speed 115200
set carrier-watch off
set handshake none
set flow-control none
set file type bin
set file name lit
set rec pack 1000
set send pack 1000
set window 5

Run the command kermit to launch C-Kermit

Ensure that you have made the right connections, and if everything went fine, terminal will print this out:

$ kermit
Connecting to /dev/ttyUSB0, speed 115200
Escape character: Ctrl-\ (ASCII 28, FS): enabled
Type the escape character followed by C to get back,
or followed by ? to see other options.
TE: 116640


Tips: If the print-out contains the following line, you might need to check the step Add Access Permission above.

/dev/ttyUSB0: Permission denied

Enable 1500000 baudrate

To enable 1500000 baudrate, you need to replace the kermit binary. See Khadas Kermit to download, and execute the following commands:

$ chmod +x kermit
$ sudo cp kermit /usr/bin/kermit

If you want to use the 1500000 baudrate, you need to modify the ~/.kermrc speed to 1500000.

See Also