There’s a HAM radio enthusiast living in Belarus (and previously Russia) who designed a telegraph keyer and named it after my grandfather, Lev Naumovich Pekler (Лев Наумович Пеклер), after meeting him briefly at the polar research base (Остров Голомянный) where he was stationed. Unfortunately this model is no longer in production, and has been superseded by newer designs, available from his website.
Played around with the Lichee Pi Zero and the Lichee Nano boards, which are nifty and powerful little things. Here are links for getting started with the Zero, as well as SD card images for booting it. And here the documentation for the Nano, and how to get embedded Linux working on it. I simply developed a few random scripts that drew patterns on the framebuffer (i.e. a TFT screen attached to it). Quick tip: to disable the blinking cursor when drawing to the framebuffer:
echo 0 > /sys/class/graphics/fbcon/cursor_blink