IoT Device (Raspberry Pi) + .NET 6.0 + .NET IoT Libraries + C# Source Code Generator + Azure IoT Hub + Azure IoT Client SDK for C# + VS Code

1. Cross-Platform Azure IoT Device
With C# Source Code Generator and .NET 6.0
Alon Fliess
Chief Architect
alonf@codevalue.net
@alon_fliess
http://alonfliess.me
http://codevalue.net

2. Ingredients
 IoT Device (Raspberry Pi)
 .NET 6.0 + .NET IoT Libraries
 C# Source Code Generator
 Azure IoT Hub + Azure IoT Client SDK for C#
 VS Code

3. About Alon Fliess
3
 Chief Architect & Founder – CodeValue
 Microsoft Regional Director
 Microsoft Azure MVP
 alonf@codevalue.net
 @alon_fliess
 http://alonfliess.me
 http://codevalue.net

4. IoT 101
var sensorData = await _bmp180.GetSensorDataAsync(Bmp180.UltraHighResolution);
var messageString = JsonConvert.SerializeObject(sensorData);
var message = new
Microsoft.Azure.Devices.Client.Message(Encoding.ASCII.GetBytes(messageString));
await deviceClient.SendEventAsync(message);

5. .NET IoT Libraries
System.Device.Gpio
 Hardware + OS
 Raspberry Pi, BeagleBoard, HummingBoard, ODROID,
and other single-board-computers that are supported
by Linux and Windows 10 IoT Core OS
 Wraps hardware access libraries on both Windows
and Linux
 Provides API for:
 General-purpose I/O (GPIO)
 Inter-Integrated Circuit (I2C)
 Serial Peripheral Interface (SPI)
 Pulse Width Modulation (PWM)
 Serial port
Device Binding
 Built on top of System.Device.Gpio
 Cross-Platform hardware driver classes
 Sensors, Displays, HMI devices and anything else that
requires software to control
 Cross-targeting .NET Standard 2.0 and up
 Full Framework, 3.1, 5, 6, mono
5

6. The wonder of Azure IoT Hub
IoT Hub
Receive device-to-cloud messages
Send cloud-to-device messages
Receive delivery acks
Receive file notifications
Direct method invocation
Receive operations monitoring events
Module identity management
Module twin management
Job Management
Send device-to-cloud
messages
Receive cloud-to-device
messages
Initiates file
uploads
Retrieve and update
twin properties
Receive direct method
requests
Service
Per-Device
Configuration Management
Message Routing
Message Enrichment
Device identity management
Device twin management
IoT Edge Device IoT Edge Management
Device Twin
Tags
Properties
Desired
Reported

7. What is a source generator?
 It lets you generate source code
 What does “generate source” mean?
 Why isn’t he saying any of these bullet points?
 So “source” I guess means source code
 And “generate” means create
 Wait.. Are source generators going to take our jobs?!

8. Your .cs
files
The C# Compiler
Project.dll
Parse
Source
Generator
Compile Emit
CST
AST
CST
Compilation IL
Source
(string)
CST

9. Referencing and Defining a Source Generator

10. A Simplified Flow
 Initialize  Register for a syntax node notification
context.RegisterForSyntaxNotifications(() => new SyntaxReceiver());
 Syntax node notification  gather code generation information
public void OnVisitSyntaxNode(SyntaxNode syntaxNode)
{
//collect information
…
}
 Execute  Generate source files and add them to the compilation
10
Your Implementation

11. IoTHubClientGenerator
 Build an IoT Device client program in seconds
 Handle configuration in multiple ways
 Use IoT Device Connection String, or Device Provisioning Service
 Support most of Azure IoT Hub protocols and protocols’ security
 Support Device Twin, Sending Telemetry, Direct Method and Cloud to Device
messages
 Support device connection status changed notification
11

12. Demo
Show me an
example!
• Raspberry Pi
• .NET 6.0 + .NET IoT
Libraries
• C# Source Code
Generator
• Azure IoT Hub + Azure
IoT Client SDK for C#
• VS Code

13. Summary & Takeaways
 .NET IoT Libraries – cross platform IoT foundation
 Azure IoT Hub – cloud scale IoT Platform
 C# + Source generators (IoTHubClientGenerator) – The easiest way to
develop Azure connected IoT device
13

14. Q
A
14

15. Alon Fliess
Chief Architect & Founder
alonf@codevalue.net
@alon_fliess
http://alonfliess.me
http://codevalue.net

16. Appendix – Demo Code
1. using System;
2. using System.Device.I2c;
3. using System.Device.Gpio;
4. using System.Threading;
5. using Iot.Device.Tcs3472x;
6. using System.Threading.Tasks;
7. using IoTHubClientGeneratorSDK;
8. using Microsoft.Azure.Devices.Client;
9. using Microsoft.Azure.Devices.Client.Exceptions;
10. using Microsoft.Azure.Devices.Client.Transport.Mqtt;
11. using System.Text;
12.

17. Appendix – Demo Code
17
13. namespace DotnetConf
14. {
15. [IoTHub(GeneratedSendMethodName = "SendAsync")]
16. partial class DotNetDevice
17. {
18. [Reported("LastColorName")]
19. private string _lastColorName;
20.
[Desired]
21. private int ReportingIntervalInSeconds { get; set; } = 10;
22.
[Device(ConnectionString="[Configuration.IoTHubConnectionString]")]
23. DeviceClient MyClient {get;set;}
24.

18. Appendix – Demo Code
18
25. static async Task Main(string[] args)
26. {
27. var device = new DoteNetDevice();
28. await device.InitIoTHubClientAsync();
29.
30. I2cConnectionSettings i2cSettings = new(1, 0x29);
31. using I2cDevice i2cDevice =
32. I2cDevice.Create(i2cSettings);
33. using Tcs3472x tcs3472X = new(i2cDevice);
34. long i = 0;
35. device.InitGpioController();
36.

19. Appendix – Demo Code
19
37. while (!Console.KeyAvailable)
38. {
39. Console.WriteLine(
40. $"ID: {tcs3472X.ChipId} Gain: {tcs3472X.Gain} Time to wait: {tcs3472X.IsClearInterrupt}");
41. var col = tcs3472X.GetColor();
42. var color = $"{col.R},{col.G},{col.B}";
43. device.LastColorName = col.Name;
44.
Console.WriteLine($"Valid data: {tcs3472X.IsValidData} Clear Interrupt: {tcs3472X.IsClearInterrupt}");
45.
46. if (tcs3472X.IsValidData)
47. {
48. Console.WriteLine(
49. $"{device.ReportingIntervalInSeconds} seconds trigger, sending data, color: {color}");
50. await device.SendAsync($"{{"color":"{color}"}}", (++i).ToString(), new CancellationToken());
51. }
52. await Task.Delay(TimeSpan.FromSeconds(device.ReportingIntervalInSeconds));
53. }
54. }

20. Appendix – Demo Code
20
55. private GpioController _gpioController;
56.
57. private void InitGpioController()
58. {
59. _gpioController = new GpioController ();
60. // Sets the pin to output mode so we can switch something on
61. _gpioController.OpenPin(Configuration.GreenLedPin,
62. PinMode.Output);
63. }
64.

21. Appendix – Demo Code
21
65. [C2DMessage(AutoComplete = true)]
66. private void Cloud2DeviceMessage(Message receivedMessage)
67. {
68. string messageData = Encoding.ASCII.GetString(receivedMessage.GetBytes());
69. Console.WriteLine($"Received message: [{messageData}]");
70. try
71. {
72. var colors = messageData.Split(",");
73. var red = int.Parse(colors[0]);
74. var green = int.Parse(colors[1]);
75. var blue = int.Parse(colors[2]);
76.
77. Console.WriteLine($"Color: red:{red}, green:{green}, blue:{blue}");
78.

22. Appendix – Demo Code
22
79. if (green > red && green > blue)
80. {
81. _gpioController.Write(Configuration.GreenLedPin, PinValue.High);
82. }
83. else
84. {
85. _gpioController.Write(Configuration.GreenLedPin, PinValue.Low);
86. }
87. }
88. catch (System.Exception e)
89. {
90.
Console.WriteLine(e);
91. }
92. }

23. Appendix – Demo Code
23
93. [ConnectionStatus]
94. private (ConnectionStatus Status, ConnectionStatusChangeReason Reason) DeviceConnectionStatus { get; set; }
95.
96. [IoTHubErrorHandler]
97. void IoTHubErrorHandler(string errorMessage, Exception exception)
98. {
99. Console.WriteLine($"{errorMessage}, Exception: {exception.Message}");
100. }
101. }
102.}