I'm working on a spare-time project where I have to decode a PWM coded signal. The bit protocol looks like this:
Frequency is 500Khz, each bit starts with a raising edge.
One bits have a high duty cycle of 75%. Zero bits have a high duty cycle of 25% (with a bit of margin of cause).
Now I want to read this stream into a microcontroller or DSP. I wonder what would be the simplest way to decode this signal and split it into a clock and data-stream (so I can read it in via SPI or so).
Are there any ready made converter chips that receive PWM coded single wire protocols like the one I've just described and output something more standard like SPI or so? A built-in FIFO would also come very handy.