Erste Verison mit Kollisions-Vermeidung.

Kollisions-Erkennung sollte auch funktionierten, aber das ist nicht ganz klar.

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

Sender/Sender.ino

@@ -1,19 +1,25 @@
-#include <SoftwareSerial.h>
-
 int sTx = 4;
 int sRx = 5;
-SoftwareSerial mySerial(sRx,sTx);
+
+long base = 800;
 
 int id = 0;
 int baud = 19200;
 int enable = 2;
 char c;
 int counter = 0;
+
 void setup(){
   pinMode(A0,INPUT);
   id = analogRead(A0)*10;
+  
   pinMode(enable,OUTPUT);
-  mySerial.begin(baud);
+  digitalWrite(enable,LOW);
+  
+  pinMode(sTx,OUTPUT);
+  digitalWrite(sTx,LOW);
+  
+  pinMode(sRx,INPUT);
   Serial.begin(115200);  
   Serial.print("Baud rate set to ");
   Serial.println(baud);
@@ -21,23 +27,61 @@ void setup(){
   Serial.println(id);
 }
 
-void printSerial(){
-  while (mySerial.available()){
-      c = mySerial.read();
-      Serial.print(c);
+bool sendBit(bool bt){
+  digitalWrite(sTx,bt);
+  delayMicroseconds(80);
+  if (digitalRead(sTx) != bt) return false;
+  delayMicroseconds(base-80);
+  return true;
+}
+
+bool sendChar(char c){
+  return sendBit(c & 0x01)
+      && sendBit(c & 0x02)
+      && sendBit(c & 0x04)
+      && sendBit(c & 0x08)
+      && sendBit(c & 0x10)
+      && sendBit(c & 0x20)
+      && sendBit(c & 0x40)
+      && sendBit(c & 0x80);
+}
+
+bool sendString(String s){
+  Serial.print("Sending '"+s+"'…");
+  boolean busy = false;
+  for (int i = 0; i<11; i++){
+    if (!digitalRead(sRx)) {
+      if (!busy){
+        Serial.print("busy…");
+        busy = true;
+      }
+      i = 0; // wait for free line
+    }
+    delayMicroseconds(base);
   }
+  digitalWrite(enable,HIGH);
+  bool success = sendBit(0); // erste Flanke erzeugen
+  if (success) {
+    for (char c : s){
+      if (!sendChar(c)){
+        success = false;
+        break;
+      }
+    }
+  }
+  success = success && sendChar(13);
+  success = success && sendBit(1); // letzte Flanke erzeugen
+  digitalWrite(enable,LOW);
+  Serial.println(success ? "success" : "failed");
+  return success;
 }
 
 void loop(){
-  printSerial();
-  delay(id);
-  digitalWrite(enable,HIGH);
-  mySerial.print("Arduino #");
-  mySerial.print(id);
-  mySerial.print(": Counter = ");
-  mySerial.println(counter);
-  mySerial.flush();
-  digitalWrite(enable,LOW);
-  printSerial();
   counter++;
+  String s = "Hier ist ";
+  s.concat(id);
+  s+=": counter = ";
+  s.concat(counter);
+  while (!sendString(s)) delay(10*base);
+  delay(id);
 }