Random wanderings through Microsoft Azure esp. PaaS plumbing, the IoT bits, AI on Micro controllers, AI on Edge Devices, .NET nanoFramework, .NET Core on *nix and ML.NET+ONNX
One of the easiest ways to create read-only replicas of an Azure SQL Database database is with Active geo-replication(it’s also useful for disaster recovery with geo-failure to a geo-secondary in a different Azure Region).
I then created replicas in the same region (if the application had a global customer base creating read only geo replicas in regions close to users might be worth considering) for the read-only queries.
Azure SQL Database no replicas configured
Azure Portal Create Geo Replica
I created four replicas which is the maximum number supported. If more replicas were required a secondary of a secondary (a process known as chaining) could be use to create additional geo-replicas
Azure Portal Primary Database and four Geo-replicas
Azure Application Insights showing multiple Geo-Replicas being used.
The Azure Database Geo-replication was pretty easy to setup. For a production scenario where only a portion of the database (e.g. shaped by Customer or Geography) is required it might not be the “right hammer”.
WebAPI Dapper Azure Resource Group
The other limitation I encountered was the resources used by the replication of “transaction processing” tables (in the World Wide Importers database tables like the Sales.OrderLines, Sales.CustomerTransactions etc.) which often wouldn’t be required for read-only applications.
The company builds a Software as a Service(Saas) product for managing portfolios of foreign currency forwards, options, swaps etc. Part of the solution has an application which customers use to get an “aggregated” view of their purchases.
The database queries to lookup reference data (forward curves etc.), return a shaped dataset for each supported instrument type, then “aggregating” the information with C# code consumes significant database and processing resources.
The configuration strings of the read-only replicas are loaded as the application starts.
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
var errorHandlerSettings = Configuration.GetSection(nameof(ErrorHandlerSettings));
services.Configure<ErrorHandlerSettings>(errorHandlerSettings);
var readonlyReplicaServersConnectionStringSettings = Configuration.GetSection("ReadonlyReplicaServersConnectionStringSettings");
services.Configure<List<string>>(readonlyReplicaServersConnectionStringSettings);
services.AddResponseCaching();
services.AddDapperForMSSQL();
#if DAPPER_EXTENSIONS_CACHE_MEMORY
services.AddDapperCachingInMemory(new MemoryConfiguration
{
AllMethodsEnableCache = false
});
#endif
#if DAPPER_EXTENSIONS_CACHE_REDIS
services.AddDapperCachingInRedis(new RedisConfiguration
{
AllMethodsEnableCache = false,
KeyPrefix = Configuration.GetValue<string>("RedisKeyPrefix"),
ConnectionString = Configuration.GetConnectionString("RedisConnection")
});
#endif
services.AddApplicationInsightsTelemetry();
}
Then code was added to the controller to randomly select which read-only replica to use. More complex approaches were considered but not implemented for the initial version.
[ApiController]
[Route("api/[controller]")]
public class StockItemsReadonlyReplicasController : ControllerBase
{
private readonly ILogger<StockItemsReadonlyReplicasController> logger;
private readonly List<string> readonlyReplicasConnectionStrings;
public StockItemsReadonlyReplicasController(ILogger<StockItemsReadonlyReplicasController> logger, IOptions<List<string>> readonlyReplicasServerConnectionStrings)
{
this.logger = logger;
this.readonlyReplicasConnectionStrings = readonlyReplicasServerConnectionStrings.Value;
}
[HttpGet]
public async Task<ActionResult<IEnumerable<Model.StockItemListDtoV1>>> Get()
{
IEnumerable<Model.StockItemListDtoV1> response = null;
if (readonlyReplicasConnectionStrings.Count == 0)
{
logger.LogError("No readonly replica server Connection strings configured");
return this.StatusCode(StatusCodes.Status500InternalServerError);
}
Random random = new Random(); // maybe this should be instantiated ever call, but "danger here by thy threading"
string connectionString = readonlyReplicasConnectionStrings[random.Next(0, readonlyReplicasConnectionStrings.Count)];
logger.LogTrace("Connection string {connectionString}", connectionString);
using (SqlConnection db = new SqlConnection(connectionString))
{
response = await db.QueryAsync<Model.StockItemListDtoV1>(sql: @"SELECT [StockItemID] as ""ID"", [StockItemName] as ""Name"", [RecommendedRetailPrice], [TaxRate] FROM [Warehouse].[StockItems]", commandType: CommandType.Text);
}
return this.Ok(response);
}
}
The Read-only replica server connection string setup template in appsettings.Development.json.
The Manage UserSecrets(Secrets.json) functionality was used for testing on my development machine. In production Azure App Service the array of connections strings was configured with ReadonlyReplicaServersConnectionStringSettings:0, ReadonlyReplicaServersConnectionStringSettings:1 etc. syntax
Sample application Azure App Service Configuration
Azure Application Insights with connections to different read-only replicas highlighted
I had incorrectly configured the firewall on one of the read-only replica database servers so roughly one in four connection attempts failed.
I have been working on a .NET nanoFramework library for the RAKwirelessRAK3172 module for the last couple of weeks. The devices had been in a box under my desk for a couple of months so first step was to flash them with the latest firmware using my FTDI test harness.
My sample code has compile time options for synchronous and asynchronous operation. I also include the different nanoff command lines to make updating the test devices easier.
//---------------------------------------------------------------------------------
// Copyright (c) May 2022, devMobile Software
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// https://docs.rakwireless.com/Product-Categories/WisDuo/RAK4200-Breakout-Board/AT-Command-Manual/
//---------------------------------------------------------------------------------
#define SERIAL_ASYNC_READ
//#define SERIAL_THREADED_READ
#define ST_STM32F769I_DISCOVERY // nanoff --target ST_STM32F769I_DISCOVERY --update
//#define ESP32_WROOM // nanoff --target ESP32_REV0 --serialport COM17 --update
...
namespace devMobile.IoT.LoRaWAN.nanoFramework.RAK3172
{
using System;
using System.Diagnostics;
using System.IO.Ports;
using System.Threading;
#if ESP32_WROOM
using global::nanoFramework.Hardware.Esp32; //need NuGet nanoFramework.Hardware.Esp32
#endif
public class Program
{
private static SerialPort _SerialPort;
#if SERIAL_THREADED_READ
private static Boolean _Continue = true;
#endif
#if ESP32_WROOM
private const string SerialPortId = "COM2";
#endif
...
#if ST_STM32F769I_DISCOVERY
private const string SerialPortId = "COM6";
#endif
public static void Main()
{
#if SERIAL_THREADED_READ
Thread readThread = new Thread(SerialPortProcessor);
#endif
Debug.WriteLine("devMobile.IoT.LoRaWAN.nanoFramework.RAK3172 BreakoutSerial starting");
try
{
// set GPIO functions for COM2 (this is UART1 on ESP32)
#if ESP32_WROOM
Configuration.SetPinFunction(Gpio.IO16, DeviceFunction.COM2_TX);
Configuration.SetPinFunction(Gpio.IO17, DeviceFunction.COM2_RX);
#endif
Debug.Write("Ports:");
foreach (string port in SerialPort.GetPortNames())
{
Debug.Write($" {port}");
}
Debug.WriteLine("");
using (_SerialPort = new SerialPort(SerialPortId))
{
// set parameters
_SerialPort.BaudRate = 115200;
_SerialPort.Parity = Parity.None;
_SerialPort.DataBits = 8;
_SerialPort.StopBits = StopBits.One;
_SerialPort.Handshake = Handshake.None;
_SerialPort.NewLine = "\r\n";
_SerialPort.ReadTimeout = 1000;
//_SerialPort.WatchChar = '\n'; // May 2022 WatchChar event didn't fire github issue https://github.com/nanoframework/Home/issues/1035
#if SERIAL_ASYNC_READ
_SerialPort.DataReceived += SerialDevice_DataReceived;
#endif
_SerialPort.Open();
_SerialPort.WatchChar = '\n';
#if SERIAL_THREADED_READ
readThread.Start();
#endif
for (int i = 0; i < 5; i++)
{
string atCommand;
atCommand = "AT+VER=?";
Debug.WriteLine("");
Debug.WriteLine($"{i} TX:{atCommand} bytes:{atCommand.Length}--------------------------------");
_SerialPort.WriteLine(atCommand);
Thread.Sleep(5000);
}
}
Debug.WriteLine("Done");
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
#if SERIAL_ASYNC_READ
private static void SerialDevice_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
SerialPort serialPort = (SerialPort)sender;
switch (e.EventType)
{
case SerialData.Chars:
break;
case SerialData.WatchChar:
string response = serialPort.ReadExisting();
Debug.Write(response);
break;
default:
Debug.Assert(false, $"e.EventType {e.EventType} unknown");
break;
}
}
#endif
#if SERIAL_THREADED_READ
public static void SerialPortProcessor()
{
while (_Continue)
{
try
{
string response = _SerialPort.ReadLine();
//string response = _SerialPort.ReadExisting();
Debug.Write(response);
}
catch (TimeoutException ex)
{
Debug.WriteLine($"Timeout:{ex.Message}");
}
}
}
#endif
}
}
When I requested the RAK3172 version information with “AT+VER=?” the response was spilt over two lines which is a bit of a Pain in the Arse (PitA). The RAK3172 firmware also defaults 115200 baud which seems overkill considering the throughput of a LoRaWAN link.
For some historical reason I can’t remember my controllers often had an outer try/catch and associated logging. I think may have been ensure no “sensitive” information was returned to the caller even if the application was incorrectly deployed. So I could revisit my approach I added a controller with two methods one which returns an HTTP 500 error and another which has un-caught exception.
[Route("api/[controller]")]
[ApiController]
public class StockItemsNok500Controller : ControllerBase
{
private readonly string connectionString;
private readonly ILogger<StockItemsNok500Controller> logger;
public StockItemsNok500Controller(IConfiguration configuration, ILogger<StockItemsNok500Controller> logger)
{
this.connectionString = configuration.GetConnectionString("WorldWideImportersDatabase");
this.logger = logger;
}
public async Task<ActionResult<IEnumerable<Model.StockItemListDtoV1>>> Get500()
{
IEnumerable<Model.StockItemListDtoV1> response = null;
try
{
using (SqlConnection db = new SqlConnection(this.connectionString))
{
response = await db.QueryWithRetryAsync<Model.StockItemListDtoV1>(sql: @"SELECT [StockItemID] as ""ID"", [StockItemName] as ""Name"", [RecommendedRetailPrice], [TaxRate] FROM [Warehouse].[StockItem500]", commandType: CommandType.Text);
}
}
catch (SqlException ex)
{
logger.LogError(ex, "Retrieving list of StockItems");
return this.StatusCode(StatusCodes.Status500InternalServerError);
}
return this.Ok(response);
}
}
The information returned to a caller was generic and the only useful information was the “traceId”.
StockItemsNok500Controller error page
[Route("api/[controller]")]
[ApiController]
public class StockItemsNokExceptionController : ControllerBase
{
private readonly string connectionString;
public StockItemsNokExceptionController(IConfiguration configuration)
{
this.connectionString = configuration.GetConnectionString("WorldWideImportersDatabase");
}
public async Task<ActionResult<IEnumerable<Model.StockItemListDtoV1>>> GetException()
{
IEnumerable<Model.StockItemListDtoV1> response = null;
using (SqlConnection db = new SqlConnection(this.connectionString))
{
response = await db.QueryWithRetryAsync<Model.StockItemListDtoV1>(sql: @"SELECT [StockItemID] as ""ID"", [StockItemName] as ""Name"", [RecommendedRetailPrice], [TaxRate] FROM [Warehouse].[StockItemsException]", commandType: CommandType.Text);
}
return this.Ok(response);
}
}
In “Development” mode the information returned to the caller contains a detailed stack trace that reveals implementation details which are useful for debugging but would also be useful to an attacker.
Developer StockItemsNok Controller Exception page
When not in “Development” mode no additional information is returned (not even a TraceId).
Production StockItemsNok500Controller Exception
The diagnostic stacktrace information logged by the two different controllers was essentially the same
System.Data.SqlClient.SqlException:
at System.Data.SqlClient.SqlCommand+<>c.<ExecuteDbDataReaderAsync>b__126_0 (System.Data.SqlClient, Version=4.6.1.3, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Threading.Tasks.Task+<>c.<.cctor>b__272_0 (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Threading.ExecutionContext.RunInternal (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Threading.ExecutionContext.RunInternal (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Dapper.SqlMapper+<QueryAsync>d__33`1.MoveNext (Dapper, Version=2.0.0.0, Culture=neutral, PublicKeyToken=null: /_/Dapper/SqlMapper.Async.cs:418)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Polly.Retry.AsyncRetryEngine+<ImplementationAsync>d__0`1.MoveNext (Polly, Version=7.0.0.0, Culture=neutral, PublicKeyToken=c8a3ffc3f8f825cc)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter.GetResult (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at Polly.AsyncPolicy+<ExecuteAsync>d__21`1.MoveNext (Polly, Version=7.0.0.0, Culture=neutral, PublicKeyToken=c8a3ffc3f8f825cc)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
at devMobile.WebAPIDapper.Lists.Controllers.StockItemsNokController+<Get500>d__4.MoveNext (ListsClassic, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: C:\Users\BrynLewis\source\repos\WebAPIDapper\Lists\Controllers\14.StockItemsNokController.cs:70)
One customer wanted their client application to display a corporate help desk number for staff to call for support. This information was made configurable
namespace devMobile.WebAPIDapper.Lists
{
public class ErrorHandlerSettings
{
public string Detail { get; set; } = "devMobile Lists Classic API failure";
public string Title { get; set; } = "System Error";
}
}
{
...
},
"ErrorHandlerSettings": {
"Title": "Webpage has died",
"Detail": "Something has gone wrong call the help desk on 0800-RebootIt"
},
...
}
namespace devMobile.WebAPIDapper.Lists.Controllers
{
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;
[ApiController]
public class ErrorController : Controller
{
private readonly ErrorHandlerSettings errorHandlerSettings;
public ErrorController(IOptions<ErrorHandlerSettings> errorHandlerSettings)
{
this.errorHandlerSettings = errorHandlerSettings.Value;
}
[Route("/error")]
public IActionResult HandleError([FromServices] IHostEnvironment hostEnvironment)
{
return Problem(detail: errorHandlerSettings.Detail, title: errorHandlerSettings.Title);
}
}
}
StockItemsNok Controller Error page with configurable title and details
Another customer wanted their client application to display a corporate help desk number based on the source hostname.
ClientA.SaasApplicationProvider.co.nz
ClientB.SaasApplicationProvider.co.nz
ClientC.SaasApplicationProvider.co.nz
SaasApplication.ClientD.co.nz
This information was also made configurable
namespace devMobile.WebAPIDapper.Lists
{
using System.Collections.Generic;
public class UrlSpecificSetting
{
public string Title { get; set; } = "";
public string Detail { get; set; } = "";
public UrlSpecificSetting()
{
}
public UrlSpecificSetting(string title, string detail)
{
this.Title = title;
this.Detail = detail;
}
}
public class ErrorHandlerSettings
{
public string Title { get; set; } = "System Error";
public string Detail { get; set; } = "devMobile Lists Classic API failure";
public Dictionary<string, UrlSpecificSetting> UrlSpecificSettings { get; set; }
public ErrorHandlerSettings()
{
}
public ErrorHandlerSettings(string title, string detail, Dictionary<string, UrlSpecificSetting> urlSpecificSettings )
{
Title = title;
Detail = detail;
UrlSpecificSettings = urlSpecificSettings;
}
}
}
We considered storing the title and details message in the database but that approach was discounted as we wanted to minimise dependencies.
{
...
"ErrorHandlerSettings": {
"Detail": "Default detail",
"Title": "Default title",
"UrlSpecificSettings": {
"localhost": {
"Title": "Title for localhost",
"Detail": "Detail for localhost"
},
"127.0.0.1": {
"Title": "Title for 127.0.0.1",
"Detail": "Detail for 127.0.0.1"
}
}
}
}
namespace devMobile.WebAPIDapper.Lists.Controllers
{
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;
[ApiController]
public class ErrorController : Controller
{
private readonly ErrorHandlerSettings errorHandlerSettings;
public ErrorController(IOptions<ErrorHandlerSettings> errorHandlerSettings)
{
this.errorHandlerSettings = errorHandlerSettings.Value;
}
[Route("/error")]
public IActionResult HandleError([FromServices] IHostEnvironment hostEnvironment)
{
if (!this.errorHandlerSettings.UrlSpecificSettings.ContainsKey(this.Request.Host.Host))
{
return Problem(detail: errorHandlerSettings.Detail, title: errorHandlerSettings.Title);
}
return Problem(errorHandlerSettings.UrlSpecificSettings[this.Request.Host.Host].Title, errorHandlerSettings.UrlSpecificSettings[this.Request.Host.Host].Detail);
}
}
}
The sample configuration has custom title and details text for localhost and 127.0.0.1 with a default title and details text for all other hostnames.
StockItemsNok Controller Error page with 127.0.0.1 specific title and details
StockItemsNok Controller Error page with localhost specific title and details
One customer had a staff member who would take a photo of the client application error page with their mobile and email it to us which made it really easy to track down issues. This was especially usefully as they were in an awkward timezone.
Application Insights TraceId search
Application Insights TraceId search result with exception details
With a customisable error page my approach with the outer try/catch has limited benefit and just adds complexity.
I then ran the RAK4200LoRaWANDeviceClient with DEVICE_DEVEUI_SET (devEui from label on the device), OTAA to configure the AppEui and AppKey and the device connected to The Things Network on the second attempt (typo in the DevEui).
public static void Main()
{
Result result;
Debug.WriteLine("devMobile.IoT.RAK4200LoRaWANDeviceClient starting");
try
{
// set GPIO functions for COM2 (this is UART1 on ESP32)
#if ESP32_WROOM
Configuration.SetPinFunction(Gpio.IO16, DeviceFunction.COM2_TX);
Configuration.SetPinFunction(Gpio.IO17, DeviceFunction.COM2_RX);
#endif
Debug.Write("Ports:");
foreach (string port in SerialPort.GetPortNames())
{
Debug.Write($" {port}");
}
Debug.WriteLine("");
using (Rak4200LoRaWanDevice device = new Rak4200LoRaWanDevice())
{
result = device.Initialise(SerialPortId, 9600, Parity.None, 8, StopBits.One);
if (result != Result.Success)
{
Debug.WriteLine($"Initialise failed {result}");
return;
}
#if CONFIRMED
device.OnMessageConfirmation += OnMessageConfirmationHandler;
#endif
device.OnReceiveMessage += OnReceiveMessageHandler;
#if FACTORY_RESET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} FactoryReset");
result = device.FactoryReset();
if (result != Result.Success)
{
Debug.WriteLine($"FactoryReset failed {result}");
return;
}
#endif
#if DEVICE_DEVEUI_SET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Device EUI");
result = device.DeviceEui(Config.devEui);
if (result != Result.Success)
{
Debug.WriteLine($"ADR on failed {result}");
return;
}
#endif
#if REGION_SET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Region{Region}");
result = device.Region(Region);
if (result != Result.Success)
{
Debug.WriteLine($"Region on failed {result}");
return;
}
#endif
#if ADR_SET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} ADR On");
result = device.AdrOn();
if (result != Result.Success)
{
Debug.WriteLine($"ADR on failed {result}");
return;
}
#endif
#if CONFIRMED
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Confirmed");
result = device.UplinkMessageConfirmationOn();
if (result != Result.Success)
{
Debug.WriteLine($"Confirm on failed {result}");
return;
}
#endif
#if UNCONFIRMED
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Unconfirmed");
result = device.UplinkMessageConfirmationOff();
if (result != Result.Success)
{
Debug.WriteLine($"Confirm off failed {result}");
return;
}
#endif
#if OTAA
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} OTAA");
result = device.OtaaInitialise(Config.JoinEui, Config.AppKey);
if (result != Result.Success)
{
Debug.WriteLine($"OTAA Initialise failed {result}");
return;
}
#endif
#if ABP
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} ABP");
result = device.AbpInitialise(Config.DevAddress, Config.NwksKey, Config.AppsKey);
if (result != Result.Success)
{
Debug.WriteLine($"ABP Initialise failed {result}");
return;
}
#endif
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Join start Timeout:{JoinTimeOut:hh:mm:ss}");
result = device.Join(JoinTimeOut);
if (result != Result.Success)
{
Debug.WriteLine($"Join failed {result}");
return;
}
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Join finish");
while (true)
{
#if PAYLOAD_BCD
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Send Timeout:{SendTimeout:hh:mm:ss} port:{MessagePort} payload BCD:{PayloadBcd}");
result = device.Send(MessagePort, PayloadBcd, SendTimeout);
#endif
#if PAYLOAD_BYTES
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Send Timeout:{SendTimeout:hh:mm:ss} port:{MessagePort} payload Bytes:{BitConverter.ToString(PayloadBytes)}");
result = device.Send(MessagePort, PayloadBytes, SendTimeout);
#endif
if (result != Result.Success)
{
Debug.WriteLine($"Send failed {result}");
}
Thread.Sleep(new TimeSpan(0, 5, 0));
}
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
Visual Studio Debug output for RAK4200LoRaWANDeviceClient minimal configuration connection
The Things Network “Live Data” for RAK4200LoRaWANDeviceClient minimal configuration connection
One of my client’s products has a configuration mode (button pressed as device starts) which enables a serial port (headers on board + FTDI module) for in field configuration of the onboard RAK4200 module.
devMobile's blog 