Stupid 433MHz Wireless Questions

There are tons of 433MHz devices out there. Are most likely to use a common protocol? I’d like to use an off-the-shelf remote control, but have it talk to an Arduino, using one of the countless cheap 433MHz radios for Arduino. Is that practical, or will I run into inter-operability problems?

Regards,
Ray L.

RayLivingston:
Are most likely to use a common protocol?

Some 433Mhz modules might be interoperable with another type but most are not.

Lots of different variables, freq. (channel), modulation type (ASK, FSK, OOK, etc.), data rate, etc. If you can find out the remote's protocol, that would be a start.

Disappointing, but not surprising, I guess. Am I correct in thinking the typical cheap little 433MHz boards are simply modulators/de-modulators, with no actual logic, and the software determines the encoding, timing, etc.? I note they typically have only Gnd, Vcc, and "Data" connections, so I am assuming the "Data" pin simply indicates the presence or absence of a 433MHz carrier? If so, then it should be simply a matter of software to make one of those receivers understand what almost any remote is sending.

Regards,
Ray L.

RayLivingston:
If so, then it should be simply a matter of software to make one of those receivers understand what almost any remote is sending.

That might be the case for the simple OOK devices, but I would you use 'software' to have a OOK receiver descode FSK, AFSK or even LoRa ?

srnet:
That might be the case for the simple OOK devices, but I would you use 'software' to have a OOK receiver descode FSK, AFSK or even LoRa ?

But are the $2 Rf remotes sold on EBay likely to use those?? My guess is most of them use the simplest possible protocols.
I notice the RadioHead library seems to support a VERY wide range of different protocols:

Drivers
The following Drivers are provided:

  • RH_RF22 Works with Hope-RF RF22B and RF23B based transceivers, and compatible chips and modules, including the RFM22B transceiver module such as this bare module: http://www.sparkfun.com/products/10153 and this shield: http://www.sparkfun.com/products/11018 and this board: Anarduino MiniWireless Details and RF23BP modules such as: http://www.anarduino.com/details.jsp?pid=130 Supports GFSK, FSK and OOK. Access to other chip features such as on-chip temperature measurement, analog-digital converter, transmitter power control etc is also provided.
  • RH_RF24 Works with Silicon Labs Si4460/4461/4463/4464 family of transceivers chip, and the equivalent HopeRF RF24/26/27 family of chips and the HopeRF RFM24W/26W/27W modules. Supports GFSK, FSK and OOK. Access to other chip features such as on-chip temperature measurement, analog-digital converter, transmitter power control etc is also provided.
  • RH_RF69 Works with Hope-RF RF69B based radio modules, such as the RFM69 module, (as used on the excellent Moteino and Moteino-USB boards from LowPowerLab All about Moteino | LowPowerLab ) and compatible chips and modules such as RFM69W, RFM69HW, RFM69CW, RFM69HCW (Semtech SX1231, SX1231H). Also works with Anarduino MiniWireless -CW and -HW boards Anarduino MiniWireless Details including the marvellous high powered MinWireless-HW (with 20dBm output for excellent range). Supports GFSK, FSK.
  • RH_NRF24 Works with Nordic nRF24 based 2.4GHz radio modules, such as nRF24L01 and others. Also works with Hope-RF RFM73 and compatible devices (such as BK2423). nRF24L01 and RFM73 can interoperate with each other.
  • RH_NRF905 Works with Nordic nRF905 based 433/868/915 MHz radio modules.
  • RH_NRF51 Works with Nordic nRF51 compatible 2.4 GHz SoC/devices such as the nRF51822. Also works with Sparkfun nRF52832 breakout board, with Arduino 1.6.13 and Sparkfun nRF52 boards manager 0.2.3
  • RH_RF95 Works with Semtech SX1276/77/78/79, Modtronix inAir4 and inAir9, and HopeRF RFM95/96/97/98 and other similar LoRa capable radios. Supports Long Range (LoRa) with spread spectrum frequency hopping, large payloads etc. FSK/GFSK/OOK modes are not (yet) supported.
  • RH_MRF89 Works with Microchip MRF89XA and compatible transceivers. and modules such as MRF89XAM9A.
  • RH_CC110 Works with Texas Instruments CC110L transceivers and compatible modules such as Anaren AIR BoosterPack 430BOOST-CC110L
  • RH_E32 Works with EBYTE E32-TTL-1W serial radio transceivers (and possibly other transceivers in the same family)
  • RH_ASK Works with a range of inexpensive ASK (amplitude shift keying) RF transceivers such as RX-B1 (also known as ST-RX04-ASK) receiver; TX-C1 transmitter and DR3100 transceiver; FS1000A/XY-MK-5V transceiver; HopeRF RFM83C / RFM85. Supports ASK (OOK).
  • RH_Serial Works with RS232, RS422, RS485, RS488 and other point-to-point and multidropped serial connections, or with TTL serial UARTs such as those on Arduino and many other processors, or with data radios with a serial port interface. RH_Serial provides packetization and error detection over any hardware or virtual serial connection. Also builds and runs on Linux and OSX.
  • RH_TCP For use with simulated sketches compiled and running on Linux. Works with tools/etherSimulator.pl to pass messages between simulated sketches, allowing testing of Manager classes on Linux and without need for real radios or other transport hardware.
  • RHEncryptedDriver Adds encryption and decryption to any RadioHead transport driver, using any encrpytion cipher supported by ArduinoLibs Cryptogrphic Library Arduino Cryptography Library: Arduino Cryptography Library

Drivers can be used on their own to provide unaddressed, unreliable datagrams. All drivers have the same identical API. Or you can use any Driver with any of the Managers described below.
We welcome contributions of well tested and well documented code to support other transports.
Managers
The following Mangers are provided:

  • RHDatagram Addressed, unreliable variable length messages, with optional broadcast facilities.
  • RHReliableDatagram Addressed, reliable, retransmitted, acknowledged variable length messages.
  • RHRouter Multi-hop delivery from source node to destination node via 0 or more intermediate nodes, with manual routing.
  • RHMesh Multi-hop delivery with automatic route discovery and rediscovery.

Any Manager may be used with any Driver.

RayLivingston:
But are the $2 Rf remotes sold on EBay likely to use those?? My guess is most of them use the simplest possible protocols.

Cheap '$2 RF remotes sold on EBay' are unlikley to use FSK or AFSK, but that was not your original question.

srnet:
Cheap '$2 RF remotes sold on EBay' are unlikley to use FSK or AFSK, but that was not your original question.

Then I guess I was not clear enough. What I'd like to do is use one of the cheap LED controller remotes sold on E-Bay and other places, to control an Arduino. It appears to me the cheap hardware:
(http://www.ebay.com/itm/433Mhz-RF-transmitter-receiver-link-kit-for-Arduino-ARM-MC-U-remote-control-/253142492604?hash=item3af077e5bc:g:TWoAAOSwOsBZn4pZ)
is nothing more than the most rudimentary FSK encoder/decoder - carrier present outputs a 1, no carrier present outputs a 0, or vice-versa. The software I've looked at typically bit-bangs on the transmitter, and connects the Rx pin to an interrupt-on-change handler on the Arduino. The rest is "just software". The remotes, AFAICT, nearly always use a 32kHZ bit rate, so they can use a cheap watch crystal for timing.
Regards,
Ray L.

RayLivingston:
It appears to me the cheap hardware:
(http://www.ebay.com/itm/433Mhz-RF-transmitter-receiver-link-kit-for-Arduino-ARM-MC-U-remote-control-/253142492604?hash=item3af077e5bc:g:TWoAAOSwOsBZn4pZ)
is nothing more than the most rudimentary FSK encoder/decoder - carrier present outputs a 1, no carrier present outputs a 0, or vice-versa

Your describing OOK; on off keying.

FSK is frequency shift keying, one carrier frequency for a '1' another carrier frequency (perhaps 5Khz lower or higher) for a '0'.