A radar motion detector

The RadarTx uses a microwave doppler radar sensor.
Upon detection these outputs are created: A LED flashes, red if battery voltage is low, else green.
The relay terminal block contacts are closed if switch #4 is ON, Rating 5A 250V ~.
At the beginning and end of detection a command is transmitted if switch #2 is ON. The key code is determined by start or end of detection, and switch #3.
An information message is transmitted at detection end with detection duration and battery voltage if switch #1 is ON.
It is powered by 4 AA NiMh cells. The charge voltage can be 9 to 14 V, 300 MA. When charged, the small red LED goes out.

These are assembly photographs.
These are the circuit diagrams of the Radar Transmitter
This is the Radar Transmitter processor program