Using one Arduino Shield for multiple Arduinos


(Jason) #1

Hi,
There’s a couple efforts going on right now to allow the use of Arduinos as cheap sensor/field nodes. These Arduino field nodes are cheap to implement because wireless modules like the nRF24L01 are super cheap, like $2 each. So the idea is that the sensor network is linked by cheap wireless modules. The missing piece is the ethernet connected gateway.

I see that SmartThings has a “SmartThings shield” for Arduino to make an Arduino talk to the SmartThings Hub. Can the ST-shield equipped Arduino act as the gateway Arduino to collect data from all the sensor nodes and present them as discrete sensors to the Hub? So I have 10 temperature sensors, 5 humidity sensors, some relay output Arduinos, some water sensing Arduinos all using nRF24L01 modules. They talk to a single Arduino that acts as the gateway to presents all this data to the Hub.

The shield and hub is pretty expensive. I wouldn’t mind it if I only have to buy one of each and then I can scale out my sensors. But it would defeat the purpose to have to buy a $30 shield for EACH sensor node. Especially since some sensor nodes are battery powered and sleep most of the time in a way that’s very easy to do with the nRF solution.


(Jason) #2

Follow up question - how does the Shield communicate with the Hub? Is it just an xbee radio?


(Huntb) #3

The shield communicates to the hub via ZigBee. As for using discrete sensors that report to the Arduino that is connected to the hub, it might be possible, but the documentation on the SmartShield is pretty limited. My old college professor is now the VP of hardware engineering for SmartThings so I am going to see if he can help me get some more information on it.

The issue that you will have in doing this is that the hub will see the SmartShield as only one “thing” with multiple attributes and you will have to custom write the code for the device type which could get extremely tedious when adding or updating new sensors.


(Dome) #4

I believe that the SmartThings engineers are hoping to add multiple devices per tile at some point, but I haven’t seen any updates on that in awhile. I’m in sorta the same boat - I’m building a to interface sensors and an LED light strip with SmartThings via an Arduino (and later, I’m going to make the project into an Arduino compatible board). I’d like to be able to, for example, put multiple switches on one device. It would also be nice to break away from the Arduino form factor if I wanted to and use something other than a shield to communicate with the cloud.

I’ll be curious to see how your efforts pan out.


(Brant Fischer) #5

Hello,

I am new to Smartthings, but would like to implement this exact idea. I plan on created multiple cheaper nodes and want to connect to one gateway. It looks like this hasn’t had any action since last May. Have any of you made any advancements getting this idea to work?

Thanks


(Dan) #6

Brant,
Take a look at a similar idea/effort here

Dan