@mrburnette i ll try to follow the example you proposed!lets see how it goes!
thrylosthyra7:
@mrburnette i ll try to follow the example you proposed!lets see how it goes!
Great. In the hackster.io article, I used 2 of these modules:
http://www.ebay.com/itm/RFM12B-Wireless-Transceiver-915Mhz-HopeRF-RFM12B-915S2P-Arduino-Wireless-/181189975397
I bought 4 for $20 which included shipping.
You can use any Arduino, but I used a ProMini running at 3.3V (2 AA batteries.) I used this specific one:
5PCS Pro Mini atmega328 5V 16M Replace ATmega128 Arduino Compatible Nano | eBay but they are available in single units, too. Note that these are marked 5V boards to be withing the official spec of Atmel. I have used them in many 3.3V projects without issue. However, this is a 3.3V 8MHz board:
http://www.ebay.com/itm/5PCS-Pro-Mini-atmega328-3-3V-8M-board-Replace-ATmega128-Arduino-Compatible-Nano-/310941837187
You will need to make a decision on which to use... 16MHz or 8MHz. There really is no reason that I can think of that would require anything over a 8MHz unit and it will consume less power, too. Still, this is not be considered a battery-powered project.
Running at 3.3V eliminates any need for voltage level conversion with the RFM12B.
My unit was built as a test and sends a stream of test ASCII which is monitored by the central receiver. In your case, you will simply need to use a digital input, monitor that pin, and send something to the central unit for decoding and parsing. Take care to build a protocol that handles all of your needs. For example, if you build an on/off protocol (EX: UNIT#, SENSOR#, STATE) then that implies a digital On/Off state. Now, you cannot do analog temperature! So, take some time and do research in how to build you signaling states. There are plenty of examples out on the Web, so read. There is no reason to burden yourself with building this protocol from scratch when it has been done many times.
Have fun with your project. Start small with 1 remote and 1 receiver. Then expand. There are lots of small issues that must be worked out. In fact, you may want to just duplicate what I did and use the remote unit to run around the premise and determine if you are getting any signal issues: blocking, interference, range, etc.
Ray