Move settings/open of port into convenience initialiser.

This avoids attempting to open a serial port multiple times, which can be problematic if a blocking connection is used. Instead settings and port connection should be handled prior to designated inititializer.

Package.resolved

@@ -0,0 +1,25 @@
+{
+  "object": {
+    "pins": [
+      {
+        "package": "SwiftSerial",
+        "repositoryURL": "https://vato.ddns.net/gitlab/vato007/SwiftSerial.git",
+        "state": {
+          "branch": "master",
+          "revision": "0e824cc38c6802e69543d0c1406d34babfd68e2e",
+          "version": null
+        }
+      },
+      {
+        "package": "SwiftyGPIO",
+        "repositoryURL": "https://github.com/uraimo/SwiftyGPIO.git",
+        "state": {
+          "branch": null,
+          "revision": "2038228e020cf12a62012b1ebe36bb9b8e6fdb6a",
+          "version": "1.2.5"
+        }
+      }
+    ]
+  },
+  "version": 1
+}

Sources/Swift2dCar/Esp32ServoOutput.swift

@@ -30,14 +30,15 @@ public class Esp32ServoOutput : PWMOutput {
         self.serialPort = port
     }
     
-    public convenience init?(forChannel channel: UInt8, forPin pin: UInt8, onPort port: String) {
-        self.init(forChannel: channel, forPin: pin, onPort: SerialPort(path: port))
+    public convenience init?(forChannel channel: UInt8, forPin pin: UInt8, onPort port: String) throws {
+        let initPort = SerialPort(path: port)
+        try initPort.openPort()
+        initPort.setSettings(receiveRate: .baud115200, transmitRate: .baud115200, minimumBytesToRead: 1)
+        self.init(forChannel: channel, forPin: pin, onPort: initPort)
     }
     
     public func initPWM() {
         do {
-            try serialPort.openPort()
-            serialPort.setSettings(receiveRate: .baud115200, transmitRate: .baud115200, minimumBytesToRead: 1)
             let bytesWritten = try serialPort.writeData(Data([0, 1, channel, pin]))
             if bytesWritten != 4 {
                 print("Wrote %d bytes, but should have written 4",  bytesWritten)