I need to do something similar, sending a byte of data taken from I/O pins configured as inputs and duplicating them on another wixel, like the I/O repeater but as fast as possible. So I'm also hopeful the test_radio_signal_tx AND rx will serve as a good starting point, and yes I see where there are timing loops I could alter or remove. However, as the transmit side will be battery driven, and will not need to continuously send data, I'd like to be able to lower supply current when there is no change. So most likely I'll want to sample my input pins rapidly and defer transmitting unless I see that there has actually been a state change, or if the input pins can be configured as edge triggered interrupt lines than I won't have to sample constantly.
But either way, would regulating the transmit periods save any significant battery drain? And, if there is a delay associated with going from a standby (or receive I guess) mode into transmit mode, would that cause me to be right back to the slower response of the I/O repeater?
Finally, if there is no such delay but the standby current is still higher than I'd like, the next step in low battery drain would be to put the wixel MCU into low power sleep mode, perhaps when there have been no state changes in 1/2 hour or so. Of course I'd need a low power external circuit to sense ANY state change and generate a wake-up pulse for the wixel. I do understand that in a scheme like that the initial state change that caused the wake up might be lost, and I suspect that the wake up process would add some delay before a transmission could occur anyway, right? Even so, it could serve as a convenient 'auto off" feature, since I'm already sure I'll forget to turn off power when I'm not using this project.