PICAXE 4-channel RF remote switch

As described in the "Reliable 4-Channel RF Switch" (September 2006), the outputs from low-cost RF remote control modules often need to be conditioned to eliminate noise-induced effects. For basic applications, this might consist of a simple monostable circuit and "set-reset" latch in line with each output.

To simplify construction, these functions can be integrated into a PICAXE microcontroller (IC1) running some simple BASIC code, as demonstrated by this design. It uses an Oatley Electronics (www.oatleye.com) 4-channel receiver module (RX7) and matching transmitter (TX7).

After a short power-up delay, the program scans for a logic high level on any of its four inputs, which may originate from the UHF module outputs or a pushbutton switch (S1-S4). When an input goes high, the matching output is immediately toggled. A short (100ms) delay is then executed before scanning the inputs again.