How do I get a sensor to communicate wirelessly with an arduino

Projects General Guidance
1

So I'm a bit confused.

I've found things like the XBee and the RF24, but they seem to be means for two arduinos to interact wirelessly. What if I want a sensor to communicate wirelessly with one arduino?

What i'd like to do is have an ultrasonic rangefinding sensor broadcast the values it detects wirelessly to an Uno (That's about 20 feet away) that I have plugged into my computer that's using the values it receives to effect a variable in Max/MSP.

Can someone give me a product name and a tutorial of how I'd be able to set up such sensor-to-arduino wireless communication?

2

You will need some sort of processor, on the sensor, to format the data and control the transmitter.

3

You need zigbee radio + arduino + sensor. The sensor itself is usually not smart enough to send data to zigbee. If you have higher budget for sensor, get maxbotix serial sonic ranger. No arduino needed.

4

To do precisely what you want in general with a random sensor, what you need is to put the sensor on an Xbee, and put a second Xbee on the Arduino. Digi's gigantic novel of documentation explains how you can take readings from a sensor that is connected to one of their devices. It has an ADC and a micro built right in.

edit: Sorry, forgot you specified a range finding sensor. That might still be doable just with an Xbee. I wouldn't know for sure.

More edit: Ah yes, should still work. See http://examples.digi.com/
for tons of examples of various ways to wire up and program an Xbee.

5

Thanks for the help! Would I be able to hook up 3 range finding sensors and a servo to a single xBee?

Basically the sensors are set up on an triangle array that rotates back and forth 120 degrees to detect range 360 degrees

6

Also would I be able to use an nRF24L01 rather than an xBee? They are much much cheaper and budget is an issue for me

7

InverseReverse:
Also would I be able to use an nRF24L01 rather than an xBee? They are much much cheaper and budget is an issue for me

Well, no. Physical computing = sensors + actuators + processor. If you can't program the rf module to talk with sonic rangers and servo, you need arduino as the processor. Most of the time you can't program the rf module. Xbee is exception. Programming xbee requies different toolchain than arduino software, so Fe on this forum can help you.

8

The extremely cheap ($2) 433 MHz transmitter and receiver modules will work fine for this purpose. Each transmitter and receiver needs its own Arduino (about $3 each for the eBay versions), but that could be a very small board like the Pro Mini or even smaller. One Pro Mini with a transmitter could handle a number of sensors.

You will need to use the VirtualWire or RadioHead libraries for reliable communications.

9

Check this for some 433 RxTx ideas 433MHz_Tx_Rx
Cheers, Rob