I'm developing an remote heating control with and arduino yun, a temperature sensor and a relay . All is working very well now, and I can access the data stored in an sqlite database with an external java app via webservices, and read historical temperature data.
But I'm more ambitiuos now :). I think that the next step is to deploy multiple temperature sensors in my home and one sensor outside. Then I can have a "temperature map" of the diferent rooms in my house, and store data about the relation between the temperature inside and outside, etc.
That can be easily achieved with more arduino yuns... but the cost is a problem. An arduino yun + temperature sensor costs more or less 70€. I wonder if this can be achieved in other way.
What is the cheapest way to add temperature node sensor to an arduino yun (wireless)?
Thanks in advance
If cost is a problem, I submit that the "other way" is something that does not include any more Yuns.
Since you already have a Yun working the way you want it, one option is to expand that into a base station for an NRF24 network.
I imagine the cheapest option is to make up your own board with a basic Atmel chip, a DS18B20 and a NRF24 module for about Eu10. It wouldn't cost much more if you just use a Uno, and it would be rather easier.
nRF24L01+ transceivers are very cheap and easy to use with an Arduino, but in my experience the cheap non-amplified ones only have an effective range of a few yards. One option with more range is XBee sensors, but they cost a lot more. Another option is an RFµ-328 Arduino which has an integral radio transceiver. They look good on paper, but I've no experience with them.
Check out JeeLabs:
Wow! They are some cool kit!
thank you a lot for your answers. I will take a look at the three alternatives (xbee, NRF24 modules and jeenodes).
NRF24 node is very cheap, but I'm not very expert with electronics, and I'm not sure if I can make this work
Perhaps I will try with jeenodes, they are in the middle between nrf24 and xb24 (in cost).
Thank you again.
I'm very interested to hear how you made out on this, as I've been trying to set up something similar for almost a year. I ended up going with the XBee Series 2 modules to connect a variety of different Arduinos connected to ds18b20 temp sensors for my network. As for the XBees, they were easy enough to figure out once I discovered the XBee API library at GitHub - andrewrapp/xbee-arduino: Arduino library for communicating with XBee radios in API mode.
The hard part in my experience came down to setting up the base station. It seems like all the documentation on XBee/Zigbee was written in 2011 for some reason. Which means most of it was written before Raspberry Pi, Arduino Yun, Beaglebone Black, node.js etc... There is an open source "Xbee Internet Gateway" application XBeeInternetGateway · GitHub but it was written for a specific appliance (the ConnectPort) though a Raspberry Pi port has been in beta.
The furthest I've managed to get has been using a node.js-based visual editor called http://nodered.org/ that can be run on an RPi or Beaglebone and includes modules for XBee.
Still, I think the Arduino Yun would make a better base station if more information on how to interface it with different wireless protocols surfaces.
actually I'm using an arduino YUN as base station, and as remote nodes, I use a low cost arduino leonardo, and DS18b24 temperature sensor and a NRF24L01 radio transceptor. The total amount for each remote node is more or less 12€.
Pros: it is very cheap, and easy to make it work.
Cons: when using the NRF24l01 radio indoor, the distance to the base station depends on walls, doors, and so on. My project can handle up to 5 remote sensors, but actually I have only one remote node. But sometimes I receive garbage data in the other 4 free channels... maybe from another device (maybe from a neighbor)...
Another problem that I have, in the arduino yun is in the sketch. Do a blank sketch, and import the NRF24l01, the DS18b24 and the Bridge libraries. Do a simple temperature measurement and listen to the radio, and your sketch will consume the 85% or 90% of the available memory for sketchs...
You can see more details of my project here:
I just wrote a post in my blog that you may find interesting. Basically I want to do the something similar than you , I would like to have several nodes collecting telemetry data and send it to the Yún, than then will show it in a nice HTML.
Here is the link: