Like most of my posts regarding nanoFramework and the M5Core2, I owe a debt to those who created this stuff and I’m really just going through some of the samples etc. Trying them out and documenting my findings. This post is no different, it’s based on the Welcome to the .NET nanoFramework WebServer repository

Add the NuGet package nanoFramework.WebServer to your nanoFramework project.

You’ll need to also include code to connect to your WiFi, so checkout my post on that subject – Wifi using nanoFramework on the M5Core2.

Assuming you’ve connected to your WiFi, we can set up a WebServer like this

using var server = new WebServer(80, HttpProtocol.Http, new[] { typeof(PowerController) });
server.Start();

Thread.Sleep(Timeout.Infinite);

The first line supplies an array of controllers, so you can have multiple controllers for your different endpoints. In this case we’ve just got the single controller PowerController. This is a simple class that includes RouteAtrribute and MethodAttribute adorned methods to acts as routes/endpoints.

Let’s look at the PowerController, which just returns some M5Core2.Power values when accessed via http://m5core2_ip_address/power.

public class PowerController
{
   [Route("power")]
   [Method("GET")]
   public void PowerRoute(WebServerEventArgs e)
   {
      var power = M5Core2.Power;
           
      var sb = new StringBuilder();
      sb.AppendLine("Power:");
      sb.AppendLine($"  Adc Frequency: {power.AdcFrequency}");
      sb.AppendLine($"  Adc Pin Current: {power.AdcPinCurrent}");
      sb.AppendLine($"  Adc Pin Current Setting: {power.AdcPinCurrentSetting}");
      sb.AppendLine($"  Adc Pin Enabled: {power.AdcPinEnabled}");
      sb.AppendLine($"  Batt. Temp. Monitor: {power.BatteryTemperatureMonitoring}");
      sb.AppendLine($"  Charging Current: {power.ChargingCurrent}");
      sb.AppendLine($"  Charging Stop Threshold: {power.ChargingStopThreshold}");
      sb.AppendLine($"  Charging Voltage: {power.ChargingVoltage}");
      sb.AppendLine($"  Dc Dc1 Voltage: {power.DcDc1Voltage.Millivolts} mV");
      sb.AppendLine($"  Dc Dc2 Voltage: {power.DcDc2Voltage.Millivolts} mV");
      sb.AppendLine($"  Dc Dc3 Voltage: {power.DcDc3Voltage.Millivolts} mV");
      sb.AppendLine($"  EXTEN Enable: {power.EXTENEnable}");
      sb.AppendLine($"  VOff Voltage: {power.VoffVoltage}");
      sb.AppendLine($"  Gpio0 Behavior: {power.Gpio0Behavior}");
      sb.AppendLine($"  Gpio0 Value: {power.Gpio0Value}");

      e.Context.Response.ContentType = "text/plain";
      WebServer.OutPutStream(e.Context.Response, sb.ToString());
}

As you can see from the last line of code, we send the response back with our payload, the string of power information.

We can also return HTTP codes using

WebServer.OutputHttpCode(e.Context.Response, HttpStatusCode.OK);

This is great, but what’s the IP address of our IoT device, so I can access the web server?

Well, ofcourse you could check your router or DHCP server, but better still, let’s output the IP address to the M5Core2 screen using

Console.WriteLine(IPGlobalProperties.GetIPAddress().ToString());

We can support multiple routes per method, such as

[ublic class PowerController
{
[Route("power")]
[Route("iotpower")]
[Method("GET")]
public void PowerRoute(WebServerEventArgs e)
{
// code removed
}

Note: Routes are usually case insensitive, unless you add the CaseSensitiveAttribute to your method.

The M5Core includes an accelerometer which allows us to measure the rate of acceleration, as well as a gyroscope to sense angular movement.

We initialize the combined AccelerometerGyroscope and calibrate it by using the following code. The number, 100 in this case, is the number of iterations to calibrate the AccelerometerGyroscope

M5Core2.AccelerometerGyroscope.Calibrate(100);

Let’s look at the code to read the accelerometer and gyroscope (we’ll also read the internal temperature of the AccelerometerGyroscope)

Console.Clear();

M5Core2.AccelerometerGyroscope.Calibrate(100);

while (true)
{
   var accelerometer = M5Core2.AccelerometerGyroscope.GetAccelerometer();
   var gyroscope = M5Core2.AccelerometerGyroscope.GetGyroscope();
   var temperature = M5Core2.AccelerometerGyroscope.GetInternalTemperature();

   Console.CursorLeft = 0;
   Console.CursorTop = 1;

   Console.WriteLine("Accelerator:");
   Console.WriteLine($"  x={accelerometer.X}");
   Console.WriteLine($"  y={accelerometer.Y}");
   Console.WriteLine($"  z={accelerometer.Z}");
   Console.WriteLine("Gyroscope:");
   Console.WriteLine($"  x={gyroscope.X}");
   Console.WriteLine($"  y={gyroscope.Y}");
   Console.WriteLine($"  z={gyroscope.Z}");
   Console.WriteLine("Internal Temp:");
   Console.WriteLine($"  Celsius={temperature.DegreesCelsius}");

   Thread.Sleep(20);
}

The nanoFramework comes with a Console class, for the M5Stack this is in the namespace nanoFramework.M5Stack.Console

Before we uses the Console we need to initialize the screen, this essentially creates the screen buffer and assigns a font from the application’s resource. As I’m testing this stuff on the M5Core2, the code looks like this.

M5Core2.InitializeScreen();

Now we can simply use the Console like we would for a Console application on Windows.

// clear the console
Console.Clear();

// output some test
Console.WriteLine("Some Text");

// change the foreground colour
Console.ForegroundColor = Color.Red;
Console.WriteLine("Some Red Text");

// change foreground and background colours
Console.BackgroundColor = Color.Yellow;
Console.ForegroundColor = Color.White;
Console.WriteLine("Some Green Text on Yellow Background");

We can also change the font by supplying a font resource, the default included is consolas_regular_16.tinyfnt. We would add the font as a resource and create the font like this

Console.Font = Resource.GetFont(Resource.FontResources.consolas_regular_16);

We can move the cursor around using

Console.CursorLeft = 3;
Console.CursorTop = 5;

We can also get the height and width of our window via the Console using

Console.WriteLine($"Height: {Console.WindowHeight}, Width: {Console.WindowWidth}");