Sending Messages with upsidedown.py

The Python script bin/upsidedown.py sends serial messages from the command-line.

Any string received by the UART interface of the AVR is displayed. (Assuming, you know, everything is working.) You can use whatever serial terminal you prefer to send messages — the Linux command screen and Python’s pySerial miniterm console are two options.

Determine your serial port

Although upsidedown.py tries to determine your serial port (COM port), if you have a lot of serial devices attached to your computer it may be wrong. To list the available serial devices on your computer use the -l flag.

$ ./upsidedown.py -l
Device                                  Description
----------------------------------------------------------------------
/dev/ttyUSB0                            FT232R USB UART

On Linux, my serial device is /dev/ttyUSB0. If the default serial port isn’t working, use the -d flag to provide an alternative, e.g., -d /dev/ttyUSB0.

Send a random message

Without any other command-line arguments, upsidedown.py will send a random message like "run."

$ ./upsidedown.py

Send a custom message

To display your own message, just add it to the command-line.

$ ./upsidedown.py stranger lights

Flash the LEDs

The special message "~" flashes the LEDs to warn you that the Demogorgon is nearby.

$ ./upsidedown.py ~