Netduino is back! Watch Bryan Costanich (formerly of Xamarin) as he walks through hacking a coffee maker into a connected appliance using Netduino and Xamarin. Netduino, recently acquired and relaunched by Wilderness Labs (www.wildernesslabs.co) is getting a new life as a brain for connected things developers that want to be able to use .NET to build connected IOT hardware.

1. We Power
Connected Things
Hardware development at the speed of software. www.wildernesslabs.co
Bryan Costanich
@bryancostanich

2. - The dream of connected things
- Controlling household electricity with a
relay
- Exposing control via a web API
- Connecting to that Web API from a
Xamarin App
Building a Netduino Powered
Connected Coffee Maker

3. Wilderness Labs
Relaunched Netduino in March.
Added Mac support.
Netduino stock at Amazon.com and
Mouser.com (international).
Building a vNext connected things
platform.
Actively working on Netduino.

4. developer.wildernesslabs.co

5. community.wildernesslabs.co

6. Connected Coffee Maker
Solution

7. Power Control
Household electricity (110V/240V) is
controlled by a relay.
Relays are electromechanical and isolate
circuits.
Controlled by a simple on/off via a digital
I/O pin.
Design @ 3D_Print_Designs repo
Assembly instructions in blog.
OutputPort relay =
new OutputPort(Pins.GPIO_PIN_D2, false);
relay.Write(true);

8. Web Server
Purpose-built for Netduino.
Modern, RESTful Web API/
Built-in JSON Support.

9. Maple Web Server Host
public class RequestHandler : RequestHandlerBase {
private static bool _isPowerOn;
public void getStatus() { StatusResponse(); }
public void postTurnOn() { TogglePower(true); StatusResponse(); }
public void postTurnOff() { TogglePower(false); StatusResponse(); }
private void TogglePower(bool val) {
_isPowerOn = val;
Ports.ONBOARD_LED.Write(val);
Ports.GPIO_PIN_D1.Write(val);
}
private void StatusResponse() {
this.Context.Response.ContentType = "application/json";
this.Context.Response.StatusCode = 200;
Hashtable result = new Hashtable { { "isPowerOn", _isPowerOn.ToString().ToLower() } };
this.Send(result);
}
}
get:/Status
post:/TurnOn
post:/TurnOff

10. Xamarin Mobile App
Xamarin.Forms + HttpClient
async private Task<bool> PowerCommand(string command) {
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://" + _hostAddress + "/" + _apiBase);
var response = await client.PostAsync(command, null);
if (response.IsSuccessStatusCode) {
if (command == "turnon") {
App.ApplianceStatus = ApplianceStatus.On;
} else {
App.ApplianceStatus = ApplianceStatus.Off;
}
}
return response.IsSuccessStatusCode;
}

11. Possible Expansion Projects
On timer.
Feedback loop for heat control w/temp sensor; what temp do
you like your coffee?
Coffee done push notification.
Scheduler.

12. Thanks.
www.wildernesslabs.co
slideshare.net/bryancostanich
Code here
Github.com/WildernessLabs/Netduino_Samples/Connected_Coffee_Maker