I went with the ProTrinket/Mayfly solution. My problem is no red light on the ProTrinket, only a green, I have pushed the reset button on the ProTrinket but still no red light. Is there a setting under tools that needs to be changed? If you look up bootloader for the ProTrinket, it says the ProTrinket must be connected to a computer via USB. In the above instructions, the Mayfly is connected to the computer via USB and the ProTrinket is connected to the Mayfly. Is that my problem?
I have loaded date/time and the blink sketch so I know the Mayfly is good.