On-Off Devices controlled via RF

My home automation network has grown to 44 devices comprising both manual and timed transmissions which may be single-character or multi-byte messages. All contain micro-controllers.

They form a mesh with various interoperability regimes. Transmissions are asynchronous at 2400 baud and last less than 100 milliseconds. The protocol used totally prevents false activation, but there are missed messages, They all use the same $5 Radiotronics transmit and receive modules.The RF components use AMK (ON-OFF) keying in the 433.92 MHZ ISM band, which may have a range up to 1 Km.The main problem to be solved is the frequent bursts from other sources, and the continual noise pulses from the receiver.

The transmitters provide short bursts with a format which may be used for any of the receivers. Unlike the RF Control messages, these messages have a two-character checksum at the end. 

The action taken by a receiver then depends on the data in the message and its design. It may be displayed or logged, or both, or used to control something.

Many of the RF devices which transmit or receive multi-byte messages have displays and are therefore described in other appropriate groups. 

This section is for the rest.