Fixed communication

module/src/config.h

@@ -9,6 +9,15 @@
 
 #include <stdint.h>
 
+
+// Baud rate for the RS485 communication
+// At 16 Mhz we pick a baud rate with a very acceptable 0.2% error rate
+// Source: http://www.robotroom.com/Asynchronous-Serial-Communication-2.html
+const uint32_t CommBaudRate = 76800;
+
+// Pin connected to the MAX485's Receiver and Driver Output Enable pins
+const uint8_t CommWriteEnablePin = 2;
+
 // How long the display should stay on once it's idle and showing the
 // current step numbers.
 const uint32_t DisplayIdleTimeout = 5000;

module/src/main.cpp

@@ -7,6 +7,7 @@
 #include <Arduino.h>
 #include <Wire.h>
 #include "global.h"
+#include "config.h"
 #include "display.h"
 #include "protocol.h"
 
@@ -22,7 +23,8 @@ void setup()
 
   // At 16 Mhz we pick a baud rate with a very acceptable 0.2% error rate
   // Source: http://www.robotroom.com/Asynchronous-Serial-Communication-2.html
-  Serial.begin(76800);
+  Serial.begin(CommBaudRate);
+  pinMode(CommWriteEnablePin, OUTPUT);
   comm.begin();
 }
 
@@ -51,6 +53,14 @@ void loop()
 
 
 
+void sendCommMessage(const uint8_t* data, uint8_t size)
+{
+  digitalWrite(CommWriteEnablePin, HIGH);
+  comm.sendMsg(data, size);
+  digitalWrite(CommWriteEnablePin, LOW);
+}
+
+
 void handleCommMessage()
 {
   uint8_t* data = comm.getData();
@@ -93,7 +103,7 @@ void handleCommMessage()
       {
         // Sender expects a response from us
         const uint8_t msg[] = { ResponseUhmWhat, moduleIndex };
-        comm.sendMsg(msg, sizeof(msg));
+        sendCommMessage(msg, sizeof(msg));
       }
   }
 }
@@ -102,7 +112,7 @@ void handleCommMessage()
 void handlePing(uint8_t* data, uint8_t length)
 {
   const uint8_t msg[] = { ResponsePing, settings.getModuleIndex() };
-  comm.sendMsg(msg, sizeof(msg));
+  sendCommMessage(msg, sizeof(msg));
 }
 
 
@@ -163,7 +173,7 @@ void handleSetPWM(uint8_t* data, uint8_t length)
   }
 
   const uint8_t msg[] = { ResponseSetPWM, settings.getModuleIndex() };
-  comm.sendMsg(msg, sizeof(msg));
+  sendCommMessage(msg, sizeof(msg));
 }
 
 
@@ -175,5 +185,5 @@ void handleGetSensors(uint8_t* data, uint8_t length)
   uint8_t sensor2 = 0;
 
   const uint8_t msg[] = { ResponseSetPWM, settings.getModuleIndex(), sensor1, sensor2 };
-  comm.sendMsg(msg, sizeof(msg));
+  sendCommMessage(msg, sizeof(msg));
 }