Audio Keyer, KEYER4, - don't store a blank CW message
A word of warning, something I only discovered by accident
DO NOT store a blank message in the CW memory. In other words, when in programming mode, the result you would get by pressing [rtn] directly after the 'E' command.
If a blank message is stored in there it may lockup if you subsequently ask it to play that (blank) stored message. In that event, normal operation is restored only by resetting/removing power.
Of course, it's not normally something you'd want to do, but ...
So far about 54 keyer modules have been supplied - roughly 80% - 90% of the number the initial expressions-of-interest suggested. Which is pretty good.
On previous experience with various synthesizer boards in the past, that ratio was lower, more like 50 - 70%.
There are still 54 boards left. They're usable for a lot of other projects that call-up an 8 pin PIC and PWM output, so if you've got other ideas and want just a PCB on it's own, just ask.