Cheap Wireless For Microcontrollers


Everybody loves microcontrollers, including the Arduino, allowing you to create whatever you imagine. That is unless you want to hack together something wireless. Originally you had to rely on the expensive XBee protocol or other wireless options, but no longer. Hobby Robotics found an extremely cheap transmitter and receiver and wrote a quick guide for wiring them up to an Arduino. Now your wireless projects can come to life, as long as you are within 500 feet and don’t mind 2400bps; minor trade offs compared to the gains of wireless freedom. Final note: You aren’t limited to Arduino, we would love to see someone modify this to work with a PIC or other microcontroller.

44 thoughts on “Cheap Wireless For Microcontrollers

  1. I used these things a couple years ago for a project at work for the same reasons: very cheap and simple. You just apply high to a pin on the transmitter and it sets the pin on the receiver high.

    A note though, you can’t just apply DC to the transmitter if you want to use these to send a simple high/low signal. The input signal has to be modulated at at least a hundred Hz or so.

  2. look at my name. i never whine about hackaday articles. until now. this is ridiculous. sure, make a little writeup for new people about the different rf modules available, but don’t insult other readers by calling these ‘new’ or that we ‘originally’ had to rely on xbee modules. i mean shit, even sfe has has had these for many years, and had a writeup nearly as many years ago. not that there’s much of anything to write up on. and i never thought i’d say it, but the fact that this is arduino based really does add more insult to injury.

  3. The problem with these modules is that when someone’s transmitting all the time, like you will be in this case, other things on that band will stop working (garage door openers, car remote locking, etc). The two common bands they make these in (433 and 315MHz) are already crowded with devices. The bands are meant for devices that send a short message and then turn off. I spent a lot of time testing these modules and while they are good for things like outdoor weather stations, they’re not good for real-time communication like you would want in robotics.

  4. These really are excellent (but as mentioned, not new). I have been using some extremely cheap versions of these for a while now, around $1 a unit. Obviously for this price i’m not getting anything I would like to use on a final project but they are just soo easy to get working on any (non-specific) micro controller.
    A note though, these do have a habbit of interfering with other RF devices, ones that aren’t even that close to the transmitters frequency.

  5. Neither hack-a-day’s summary my article claimed these were anything new. In fact I’ve used this exact product in the past for this project

    I mostly did this for the code I wrote. I’m working on a remote control project and needed to have a robust error checking lib that I could use.

    I know there are alternatives to this, but researching them takes time. It would be great if more people would give links to similar products they use.

  6. As being said, these are not new at all, these modules have been around a lot longer than the xbee standard.

    the cool thing about them though as simon sais, the 315mhz band is already used by a whole other bunch of devices, and you can use the transmitter module to controll them!
    I’ve used them together with arduino for controlling wireless switches, rc-cars etc, lots of fun!

  7. Did the Story poster even look on google? Those have been used with pic’s far longer than arduino existed.

    also, News flash: Arduino is a Pic. I know it destroys the glamour and sex appeal of the holy arduino….

    I’m just glad it’s not another zigbee worshiping article.

  8. @farthead
    Arduino is an Atmel chip, not a PIC. pic is from Microchip.
    They can be used if you have a custom bootloader with error correction. These have a LOT of noise, so you will need error correction.

  9. Ive seen the jackets wired with turn signals in them. I had a thought of creating this jacket then use a transmitter to transmit turn signals and brake lights from a moped to the jacket wirelessly. Now I just have to figure out how to do this, since I am electronically handicapped.

  10. All this BS is making me laugh, Electronoobs need to know this info so it’s usefull from that point, i’ve used these modules with pics and they are usefull but a bit limited because they usually come as a match pair tx & rx unless you fancy tuning a second rx and also limited by their speed due to being amplitude modulated

  11. wooqdeus, I’m not sure if you’re joking or not, but the answer is yes. You can use a pringle can (or a small parabolic dish) to increase the range of these devices just like any other common EM based signals.

  12. spectrum space is regulated not only by frequency and power, but by modulation modes and duty cycle.

    I strongly suspect that using these modules in the manner described is illegal. Check section 15 of the fcc rules.

    in case you are curious, penalties can be severe. the following is from a recent fcc ruling against someone:

    “Violations of the Communications Act or of the Commission’s Rules may subject the violator to monetary fines not to exceed $11,000 for each violation or each day of a continuing violation,
    seizure of equipment through in rem forfeiture action and criminal sanctions including imprisonment.”

  13. @darkore, et al

    Any pricing/ 3rd party reviews of hoperf’s stuff? Cheap short range tx/rx modules or all in one transceivers are always handy for little projects.

    These should be available for pennies in quantities of 50+… no?

  14. Tired of adding several hundred feet of cable to parts of your arduino project to alter resistance? No more!! This link shows you a new devide I discovered called a ‘resistor’.

    Now you can bring your arduino projects to life in a circuit board format without lugging the spools of cable alongside!

  15. I played with modules like these a few years ago and quite frankly I’d rather just spend some more money on a couple of Xbees or the equiv and avoid the headaches. All the error checking, noise and general quirkiness of these things is a pain in the ass.

  16. you are kidding right?!? right??!?!?!
    These things have been around for *centuries* (albeit in larger scales).

    this particular form of module is as LEAST 10 years old! They were around *long* before xbee, zigbee, bluetooth, and even wireless ethernet.

    Wow. Ive never been outright offensive to had itself. but seriously; take the diapers off.

  17. …i think that the new is not the devices theirself, but the price…i’ve never seen rf devices that low cost…and i bought a couple. But please, don’t call ’em “new” devices…

  18. I’m just getting started with Arduino and wireless communications and found this extremely helpful. This may be old news to everyone else, but I hadn’t heard of these and would never have thought to use them if I saw them on SparkFun. It’s sad to see all the negative comments, because this is great information. I’d love to see more cheap or simple alternatives to expensive or overkill electronics. I was going to buy some XBees to play with if not for this article. For less than the price of one XBee module I can make a pair of transceivers from these.

  19. I attached the output from a Parallax PIR( the transmitter..and the receiver to my Arduino. I’m basically trying to create a wireless motion sensor. The PIR goes high if triggered then sends the signal through the transmitter…arduino receives it and does something.A basic HIGH OR LOW scenario. I’m having a seems the signal won’t transmit right…any advice.

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