/// <summary>
/// Listen to the CAN Bus (via TCP) and generate MQTT Message if there is an update
/// </summary>
/// <param name="canServer"></param>
/// <param name="canPort"></param>
/// <returns></returns>
public async Task ConnectTcpCanBus(string canServer, int canPort)
{
try
{
//Create TCP Client for connection to canlogserver (=cls)
TcpClient clsClient = null;
while (clsClient == null || !clsClient.Connected)
{
try
{
clsClient = new TcpClient(canServer, canPort);
}
catch (Exception ea)
{
Console.WriteLine("FAILED TO CONNECT TO CANLOGSERVER {1}. {0}. Retry...", ea.Message, canServer);
}
await Task.Delay(TimeSpan.FromSeconds(5));
}
Console.WriteLine("CONNECTED TO CANLOGSERVER {0} ON PORT {1}", canServer, canPort);
//Create TCP Stream to read the CAN Bus Data
NetworkStream stream = clsClient.GetStream();
byte[] data = new Byte[46];
String responseData = String.Empty;
int bytes = stream.Read(data, 0, data.Length);
var previousData = "";
//Infinite Loop
while (bytes > 0)
{
//Get the string from the received bytes. The string contains "(1561746016.537099) slcan0 180#D03CFA01120B00"
responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
//Split by new line. canlogserver sends a line break after each CAN frame
foreach (var aData in responseData.Split('\n'))
{
//If there is nothing, ignore
if (aData.Length == 0)
{
continue;
}
//Each CAN frame is 45 characters and should start with a (. If not 45 chars, it is the first part of the frame received before.
if (aData.Length != 45 && aData.StartsWith("("))
{
//Store the data for next received packets to combine it.
previousData = aData;
}
else
{
//Create the CAN frame
var canFrame = new CanFrame
{
RawFrame = aData
};
//If the lenght is not 45 charactes and not starts with (, it is the second part of the frame stored above. Combine it and clear cache.
if (aData.Length != 45 && !aData.StartsWith("("))
{
canFrame.RawFrame = previousData + aData;
previousData = "";
}
Console.WriteLine("Received CAN Frame: {0}", canFrame.RawFrame);
//If forwarding is disabled for this type of frame, ignore it.
if (canFrame.CanFrameType == "0" && !_CanForwardWrite ||
canFrame.CanFrameType == "1" && !_CanForwardRead ||
canFrame.CanFrameType == "2" && !_CanForwardResponse)
{
continue;
}
//Sent the CAN frame via MQTT
await SendMQTT(canFrame);
}
}
//Reset byte counter
bytes = 0;
//Get next packages from canlogserver
bytes = stream.Read(data, 0, data.Length);
}
//Close the TCP Stream
clsClient.Close();
Console.WriteLine("Disconnected from canServer {0} Port {1}", canServer, canPort);
}
catch (Exception ea)
{
Console.WriteLine("Error while reading CanBus Server. {0}", ea);
}
finally
{
//Reconnect to the canlogserver but do not wait for this here to avoid infinite loops
_ = ConnectTcpCanBus(canServer, canPort); //Reconnect
}
}
/// <summary>
/// Sends a CAN-Message as a MQTT message
/// </summary>
/// <param name="canMsg"></param>
/// <returns></returns>
public async Task SendMQTT(CanFrame canMsg)
{
try
{
//Check if there is payload
if (canMsg.RawFrame.Trim().Length == 0)
{
return;
}
//Use Translator (if selected)
if (!string.IsNullOrEmpty(_CanTranslator))
{
//choose the translator to use and translate the message if translator exists
switch (_CanTranslator)
{
case "StiebelEltron":
var translator = new Translator.StiebelEltron.StiebelEltron();
canMsg = translator.Translate(canMsg, _NoUnits);
break;
}
}
//Verify connection to MQTT Broker is established
while (!_MqttClient.IsConnected)
{
Console.WriteLine("UNHANDLED DISCONNECT FROM MQTT BROKER");
while (!_MqttClient.IsConnected)
{
await Task.Delay(TimeSpan.FromSeconds(5));
try
{
await _MqttClient.ConnectAsync(_MqttClientOptions);
Console.WriteLine("CONNECTED TO MQTT BROKER");
}
catch
{
Console.WriteLine("RECONNECTING TO MQTT BROKER FAILED. Retrying...");
}
}
}
//Logoutput with or without tranlated MQTT message
if (string.IsNullOrEmpty(canMsg.MqttValue))
{
Console.WriteLine("Sending MQTT Message: {0} and Topic {1}", canMsg.PayloadFull.Trim(), _MqttTopic);
}
else
{
Console.WriteLine("Sending MQTT Message: {0} and Topic {1}{2}", canMsg.MqttValue, _MqttTopic, canMsg.MqttTopicExtention);
}
//Create MQTT Message
var message = new MqttApplicationMessageBuilder()
.WithTopic(_MqttTopic + canMsg.MqttTopicExtention)
.WithPayload(string.IsNullOrEmpty(canMsg.MqttValue) ? canMsg.PayloadFull : canMsg.MqttValue)
.WithExactlyOnceQoS()
.WithRetainFlag()
.Build();
//Publish MQTT Message
await _MqttClient.PublishAsync(message);
}
catch (Exception ea)
{
Console.WriteLine("ERROR while sending MQTT message. {0}", ea.ToString());
}
}