We just made another update of the white paper for the infrared subsystem:

http://neo900.org/stuff/papers/ir.pdf

The main changes:

- defined the (pretty tricky) control logic for the IR transmitter,
- simplified the LED driver and at the same time made its design more robust, and
- since the control logic is too complex for an efficient discrete design, we will use a mixed-signal array for it (like for power selection of the SIM switch). This also allows us to remove the two ICs of the receiver circuit, killing two birds with one stone.

With this update, all major aspects of the IR subsystem are now defined, closing one of our oldest "construction sites".

This specific version is at
http://neo900.org/stuff/papers/ir-20160701.pdf

The source can be found at
http://neo900.org/git/?p=misc;a=tree;f=ir

- Werner