Find the device
Determine the device to which the display is connected.
On Linux, this can be achieved by disconnecting the display from the computer & reconnecting,
then inspecting the contents of
dmesg output for USB attachment messages:
[ 3.010816] usb 1-1.4: FTDI USB Serial Device converter now attached to ttyUSB0
The above output indicates that the display is reachable through
Display a message
Next, write & run a Python script
that connects to that device location
from metlinkpid import PID
with PID.for_device('/dev/ttyUSB0') as pid:
pid.send('12:34 FUNKYTOWN~5_Limited Express|_Stops all stations except East Richard')
The PID should display the specified message instantly,
but after approximately one minute the display will self-clear.
| character to separate pages of a message:
The message in the above
send() call has three pages:
Everything in a page up to and including the
^ affects the display of the page,
and is not included in the output.
The letter specifies the animation and can be
V for a vertical upwards scroll,
H for a horizontal scroll,
N for no animation.
The number specifies the delay (in roughly quarter-seconds)
after the animation finishes and before the next page (or first page again) is shown.
~ will be right-aligned on the current line,
and text after
_ will appear on the next line.
Each page in the above example therefore spans two lines.
Some ASCII characters are not available for display,
and some “extended” Unicode characters are available.
Full details are in the documentation for the