Re: Keyer for a Ten Tec Rebel
You may wish to try the K1URC sketch. It has a keyer and much much more. https://github.com/roncarr880/TenTec_Rebel
I played around with a bunch of digital mode modems, some modes are transmit only, some receive only, some both:
CW, RTTY, PSK31, Hellschrieber, JT65, MFSK, WSPR.
It relies heavily upon using the Nokia display, but it also works headless or works with HRD using TenTec or Elecraft emulation. A small hardware mod is needed to get the most out of it. Details are in the program comments.
Another ham posted a demo on YouTube of the CW decoder. https://www.youtube.com/watch?v=GLMzMA_S24o