To investigate the functionality of the AP102, I connected an ATtiny85 to the clock and data input lines and used a logic analyzer to probe both the input and output lines. The microcontroller was programmed to output various bit patterns as described below.
I focused my investigation on four areas:
- Behavior of the “Start Frame”
- Function of the “111” bits in the “LED Frame”
- How data is forwarded to the next device
- Impact of the “End Frame”
Details can be found on Tim’s blog.