rfswitch Module

Since Origin / Contributor Maintainer Source
2016-12-01 Roman Fedorov Roman Fedorov rfswitch.c

Module for operate 433/315Mhz devices like power outlet sockets, relays, etc. This will most likely work with all popular low cost power outlet sockets with a SC5262 / SC5272, HX2262 / HX2272, PT2262 / PT2272, EV1527, RT1527, FP1527 or HS1527 chipset.

This module using some code from original rc-switch arduino lib but NodeMCU and Arduino are not fully compatible, and it cause for full rewrite rc-switch into this new rfswitch lib for NodeMCU with Lua support.

Connection of transmitter

Transmitter ESP8266 comments
vin or + 3V3 3.3 - 5 volts on ESP8266 or other power source
ground or - GND ground should be connected to ESP8266 and to power source
data pin 6 almost any pin on ESP8266

You can read more about connection, here or here.

Selecting proper protocol

Current library supports transmitting using 6 different protocols and you should use proper one for your needs. Current lua library rfswitch doesn't support receiver functional yet, so you cannot listen radio air and get protocol details using lua.

The easiest way to get correct protocol is connect radio receiver to your ESP8266 or Arduino, then run ReceiveDemo_Advanced.ino and view output in serial console (example1, example2).

You should get something like this:

Decimal: 11001351 (24Bit)
Binary: 101001111101111000000111
Tri-State: not applicable
PulseLength: 517 microseconds
Protocol: 5

Raw data: 7200,1004,528,504,1048,980,336,1176,356,1176,352,1180,1108,412,356,1172,364,1168,356,1160,1176,1124,412,336,1180,1116,440,328,1188,340,1228,1060,416,1160,380,1160,1108,464,1068,436,328,1232,1060,412,1116,440,1088,428,3024,

More detailed about low level protocol specifications could be found here You can visualize a telegram copy the raw data by paste it into http://test.sui.li/oszi/


Transmit value ising radio module.


rfswitch.send(protocol_id, pulse_length, repeat, pin, value, length)


  • protocol_id positive integer value, from 1-6
  • pulse_length length of one pulse in microseconds, usually from 100 till 650
  • repeat repeat value, usually from 1 till 5. This is synchronous task. Setting the repeat count to a large value will cause problems. The recommended limit is about 1-4, if you need more, then call it asynchronously a few more times (e.g. using node.task.post)
  • pin IO index of pin, example 6 is for GPIO12 see more
  • value positive integer value, this is the primary data which will be sent
  • length bit length of value, if value length is 3 bytes, then length is 24




-- lua transmit radio code using protocol #1
-- pulse_length 300 microseconds
-- repeat 5 times
-- use pin #7 (GPIO13)
-- value to send is 560777
-- value length is 24 bits (3 bytes)
rfswitch.send(1, 300, 5, 7, 560777, 24)