working version?

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

SoftRS485.cpp

@@ -6,60 +6,112 @@
 #include "Arduino.h"
 #include "SoftRS485.h"
 
-//#define DEBUG
+//#define SEND
 #define MSG_LEN 64
 
 // Pins
 int _RO, _RE, _DE, _DI;
-long _pulse_len = 105;
-
+long _pulse_len = 616;// 1232; // Pulslänge von 1250µs - 18µs Zeit für Operationen
+long _break = _pulse_len * 20;
 // Receive vars
-boolean _recv_bit = false;
-long _last_flip; // this is the time when the bus switched to logical zero
+boolean _line = LOW;
+long _last_flip = 0; // this is the time when the bus switched to logical zero
 byte _recv_msg[MSG_LEN];
-int _recv_pos = 0;
-int _recv_idx = 0;
 boolean _avail = false;
+long _diff = 0;
+long _now = 0;
+int _pos = 0;
+int _idx = 0;
+long _count = 0;
+boolean _reset = false;
+
+
+
+
+
 
 void interrupt485(){
-    _recv_bit = !digitalRead(_RO); // HIGH level = logical zero and vice versa
-    long now = micros();
-    long diff = now - _last_flip;
-    _last_flip = now;
-    if (diff > 20*_pulse_len){ // we received a start bit
-#ifdef DEBUG
-        Serial.print(F("State changed to ")); Serial.println(_recv_bit);
-        Serial.println(F("received start bit"));
+    _line = !digitalRead(_RO); // HIGH level = logical zero and vice versa
+    _now = micros();
+    _diff = _now - _last_flip;
+    _last_flip = _now;
+
+#ifdef RECV
+    Serial.print(!_line);
+    Serial.print("-(");
+    Serial.print(_diff);
+    Serial.print("µs)→");
+    Serial.print(_line);
+    Serial.print("   ");
 #endif
-        _recv_pos = 0;
-        _recv_idx = 0;
-        _last_flip+=_pulse_len;
+
+    if (_diff > _break){
+        _pos = 0;
+        _idx = 0;
+        _reset = true;
+#ifdef RECV
+        Serial.println("==RESET==");
+#endif
+    } else {
+        _count = _pulse_len>>1;
+        while (_count < _diff){
+            _count += _pulse_len;
+            if (_idx){
+                _recv_msg[_pos] |= !_line << _idx;
             } else {
-        long count = diff/_pulse_len;
-        for (int i=0; i<count; i++){
-            if (_recv_idx == 0) {
-                _recv_msg[_recv_pos] = (!_recv_bit);
+                _recv_msg[_pos] = !_line;
+            }
+            if (_reset){
+                _reset = false;
             } else {
-                _recv_msg[_recv_pos] |= (!_recv_bit)<<_recv_idx;
+                _idx++;
             }
-            _recv_idx++;
-            if (_recv_idx == 8){
-                _recv_idx = 0;
-                if (_recv_msg[_recv_pos] == 0x00){
-                    _avail = _recv_pos != 0;
-                    return;
+#ifdef RECV
+            Serial.print(_line);
+#endif
+            if (_idx == 8){
+                if (_recv_msg[_pos] == 0x00){
+                    _avail = true;
                 }
-                _recv_pos++;
+                _pos++;
+                _idx=0;
             }
         }
+#ifdef RECV
+        Serial.println();
+#endif
     }
 }
 
+
+
+
 void init485(int RO, int nRE, int DE, int DI){
     _RO=RO;
     _RE=nRE;
     _DE=DE;
     _DI=DI;
+    _avail = false;
+
+
+#if defined SEND || defined RECV
+    Serial.begin(115200);
+    Serial.print(F("RO = "));
+    Serial.println(_RO);
+    Serial.print(F("^RE = "));
+    Serial.println(_RE);
+    Serial.print(F("DE = "));
+    Serial.println(_DE);
+    Serial.print(F("DI = "));
+    Serial.println(_DI);
+#endif
+
+#ifdef RECV
+    Serial.println("RECV enabled");
+#endif
+#ifdef SEND
+    Serial.println("SEND enabled");
+#endif
 
     pinMode(_RO,INPUT);
 
@@ -73,18 +125,6 @@ void init485(int RO, int nRE, int DE, int DI){
     digitalWrite(_DI,LOW); // output line = LOW
 
     attachInterrupt(digitalPinToInterrupt(_RO),interrupt485,CHANGE);
-
-#ifdef DEBUG
-    Serial.begin(115200);
-    Serial.print(F("RO = "));
-    Serial.println(_RO);
-    Serial.print(F("^RE = "));
-    Serial.println(_RE);
-    Serial.print(F("DE = "));
-    Serial.println(_DE);
-    Serial.print(F("DI = "));
-    Serial.println(_DI);
-#endif
     _last_flip = micros();
 }
 
@@ -100,56 +140,57 @@ String get485message(){
 boolean writeBit(boolean bit){
     digitalWrite(_DI,!bit);
     delayMicroseconds(5);
-    if (_recv_bit != bit){ // collision!
+    if (_line != bit){ // collision!
        digitalWrite(_DE,LOW);
-#ifdef DEBUG
+#ifdef SEND
        Serial.println(F("Collision!"));
 #endif
        return false;
     }
-    delayMicroseconds(_pulse_len-12);
+    delayMicroseconds(_pulse_len-5);
     return true;
 }
 
+boolean writeByte(byte b){
+    return writeBit(b & 0x01)
+        && writeBit(b & 0x02)
+        && writeBit(b & 0x04)
+        && writeBit(b & 0x08)
+        && writeBit(b & 0x10)
+        && writeBit(b & 0x20)
+        && writeBit(b & 0x40)
+        && writeBit(b & 0x80);
+}
+
 boolean send485(char message[]){
-#ifdef DEBUG
+#ifdef SEND
     Serial.print(F("preparing to send "));
     Serial.print(message);
     Serial.print(F(": line state = "));
-    Serial.print(_recv_bit);
+    Serial.print(_line);
     Serial.print(F(" / last_flip = "));
     Serial.print(_last_flip);
     Serial.print(F(" / micros = "));
     Serial.println(micros());
 #endif
-    while (_recv_bit || (micros() - _last_flip) < (20 * _pulse_len)) {
+    while (_line || (micros() - _last_flip) < (20 * _pulse_len)) {
         delayMicroseconds(20*_pulse_len);
     }
-#ifdef DEBUG
+#ifdef SEND
     Serial.println(F("enabling driver…"));
 #endif
+    digitalWrite(_DI,LOW);
     digitalWrite(_DE,HIGH); // enable driver
-    if (!writeBit(HIGH)) return false;
-    int pos = -1;
-    boolean good = true;
+    int pos = -1; // increment pos prior to sending char!
+    boolean sync = writeBit(0);
     do {
         pos++;
-#ifdef DEBUG
-        Serial.print(F("sending character ")); Serial.println(message[pos]);
-#endif
-        good = writeBit(message[pos] & 0x01)
-            && writeBit(message[pos] & 0x02)
-            && writeBit(message[pos] & 0x04)
-            && writeBit(message[pos] & 0x08)
-            && writeBit(message[pos] & 0x10)
-            && writeBit(message[pos] & 0x20)
-            && writeBit(message[pos] & 0x40)
-            && writeBit(message[pos] & 0x80);
-    } while (good && message[pos]);
-    if (good) writeBit(1);
+        sync = sync && writeByte(message[pos]);
+    } while (sync && message[pos]);
+    digitalWrite(_DI,LOW);
     digitalWrite(_DE,LOW); // disable driver
-#ifdef DEBUG
+#ifdef SEND
     Serial.println(F("disabled driver…"));
 #endif
-    return good;
+    return sync;
 }

examples/ReceiveDemo/ReceiveDemo.ino

@@ -14,7 +14,6 @@ void setup() {
   // connect pin 3 to ^RE of Max485
   // connect pin 4 to DE of Max485
   // connect pin 5 to DI of Max485
-
 }
 
 void loop(){

examples/SendAndReceive/SendAndReceive.ino

@@ -1,5 +1,7 @@
 #include <SoftRS485.h>
 
+int count = 0;
+
 void setup() {
   Serial.begin(115200);
   Serial.println("This is SendAndReceive 0.1");
@@ -8,11 +10,11 @@ void setup() {
   // connect pin 3 to ^RE of Max485
   // connect pin 4 to DE of Max485
   // connect pin 5 to DI of Max485
-
-  while (send485("Hello World!")) {}
 }
 
 void loop() {
-  // put your main code here, to run repeatedly:
-  if (available485()) Serial.println("Received "+get485message());
+  delay(5000);
+  count++;
+  String s = "Test "+String(count);
+  send485(s.c_str());
 }

examples/TempSend/TempSend.ino

@@ -0,0 +1,35 @@
+
+#include <SoftRS485.h>
+#include <SimpleDHT.h>
+
+int pinDHT11 = 6;
+int count = 0;
+
+SimpleDHT11 dht11(pinDHT11);
+
+void setup() {
+  Serial.begin(115200);
+  Serial.println("This is TempSend 0.1");  
+  init485(2,3,4,5); // library initialization:
+  // connect pin 2 to RO of Max485
+  // connect pin 3 to ^RE of Max485
+  // connect pin 4 to DE of Max485
+  // connect pin 5 to DI of Max485 
+  while (!send485("Hello world!")) {}
+}
+
+void loop() {
+  // read without samples.
+  byte temperature = 0;
+  byte humidity = 0;
+  int err = SimpleDHTErrSuccess;
+  if ((err = dht11.read(&temperature, &humidity, NULL)) != SimpleDHTErrSuccess) {
+    Serial.print("Read DHT11 failed, err="); Serial.print(SimpleDHTErrCode(err));
+    Serial.print(","); Serial.println(SimpleDHTErrDuration(err)); delay(1000);
+    return;
+  }
+  count++;
+  String s = String(count)+" - Sample OK: "+ String(temperature)+" *C, "+String(humidity)+"% rel";
+  send485(s.c_str());
+  delay(5000);
+}