Well I am learning that hardware-wise, my open source smart watch AFE might require an interrupt pin (apparently the RTC fallback that Maxim says is why a big crystal is required just doesn’t do anything and no docs on how to set up that or polling mode) to work with the algorithm chip. That brings the cost from 20€ for 5 PCBs to 350€.
So I might need to write a new zephyr driver for the AFE chip directly and then spend months more work making an open source PPG algorithm and adjustable LED gain algorithm to keep the project going.
Well I am learning that hardware-wise, my open source smart watch AFE might require an interrupt pin (apparently the RTC fallback that Maxim says is why a big crystal is required just doesn’t do anything and no docs on how to set up that or polling mode) to work with the algorithm chip. That brings the cost from 20€ for 5 PCBs to 350€.
So I might need to write a new zephyr driver for the AFE chip directly and then spend months more work making an open source PPG algorithm and adjustable LED gain algorithm to keep the project going.