added Documentation

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

SoftRS485.cpp

@@ -11,20 +11,23 @@
 
 // Pins
 int _RO, _RE, _DE, _DI;
-long _pulse_len = 616;// 1232; // Pulslänge von 1250µs - 18µs Zeit für Operationen
-long _break = _pulse_len * 20;
-// Receive vars
+
+const long _pulse_len = 616;
+const long _break = _pulse_len * 20;
 boolean _line = LOW;
-long _last_flip = 0; // this is the time when the bus switched to logical zero
-byte _recv_msg[MSG_LEN];
-boolean _avail = false;
+long _last_flip = 0;
 long _diff = 0;
 long _now = 0;
-int _pos = 0;
-int _idx = 0;
 long _count = 0;
 boolean _reset = false;
 
+// Receive vars
+byte _recv_msg[MSG_LEN];
+boolean _avail = false;
+int _pos = 0;
+int _idx = 0;
+
+
 
 
 

examples/LCDReceive/LCDReceive.ino

@@ -1,51 +1,15 @@
-/*
-  LiquidCrystal Library - Hello World
-
- Demonstrates the use a 16x2 LCD display.  The LiquidCrystal
- library works with all LCD displays that are compatible with the
- Hitachi HD44780 driver. There are many of them out there, and you
- can usually tell them by the 16-pin interface.
-
- This sketch prints "Hello World!" to the LCD
- and shows the time.
-
-  The circuit:
- * LCD RS pin to digital pin 12
- * LCD Enable pin to digital pin 11
- * LCD D4 pin to digital pin 5
- * LCD D5 pin to digital pin 4
- * LCD D6 pin to digital pin 3
- * LCD D7 pin to digital pin 2
- * LCD R/W pin to ground
- * LCD VSS pin to ground
- * LCD VCC pin to 5V
- * 10K resistor:
- * ends to +5V and ground
- * wiper to LCD VO pin (pin 3)
-
- Library originally added 18 Apr 2008
- by David A. Mellis
- library modified 5 Jul 2009
- by Limor Fried (http://www.ladyada.net)
- example added 9 Jul 2009
- by Tom Igoe
- modified 22 Nov 2010
- by Tom Igoe
- modified 7 Nov 2016
- by Arturo Guadalupi
-
- This example code is in the public domain.
-
- http://www.arduino.cc/en/Tutorial/LiquidCrystalHelloWorld
-
-*/
+/* 
+ *  Demonstrates how to use LCDisplay in conjunction with SoftRS485:
+ *  
+ *  The main _loop_ of this program listens on the RS485 bus.
+ *  Whenever a message is received from the bus, it is displayed on the LCD.
+ */
 
 // include the library code:
 #include <LiquidCrystal.h>
 #include <SoftRS485.h>
 
-// initialize the library by associating any needed LCD interface pin
-// with the arduino pin number it is connected to
+// initialize the library by associating any needed LCD interface pin with the arduino pin number it is connected to
 const int rs = 12, en = 11, d4 = 4, d5 = 5, d6 = 6, d7 = 7;
 LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
 
@@ -54,7 +18,7 @@ void setup() {
   // set up the LCD's number of columns and rows:
   lcd.begin(16, 2);
   // Print a message to the LCD.
-  lcd.print("hello, world!");
+  lcd.print("LCDReceive 1.0");
   init485(2,3,8,9); // library initialization:
   // connect pin 2 to RO of Max485
   // connect pin 3 to ^RE of Max485
@@ -62,12 +26,10 @@ void setup() {
   // connect pin 9 to DI of Max485
 }
 
-void loop() {
-  
+void loop() {  
   if (available485()) {
-  // set the cursor to column 0, line 1
-  // (note: line 1 is the second row, since counting begins with 0):
     String s = get485message();
+    Serial.println(s);
     lcd.clear();
     lcd.setCursor(0, 0);
     lcd.print(s);

examples/ReceiveDemo/ReceiveDemo.ino

@@ -1,6 +1,6 @@
 /*
  This sketch demonstrates, how to use the SoftRS485 library.
- This library makes use of Arduinos timer 1
+ It listens on the bus and echoes incoming messages to the serial console.
  */
 
 #include <SoftRS485.h>

examples/SendButton/SendButton.ino

@@ -1,33 +0,0 @@
-/*
- This sketch demonstrates, how to use the SoftRS485 library.
- This library makes use of Arduinos timer 1
- */
-
-#include <SoftRS485.h>
-
-const int buttonPin = 10;     // the number of the pushbutton pin
-boolean button_state = true;
-
-void setup() {
-  Serial.begin(115200);
-
-  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
-
-  pinMode(buttonPin, INPUT_PULLUP);
-}
-
-void loop(){
-  boolean new_state = digitalRead(buttonPin);
-  if (new_state != button_state){
-    button_state = new_state;
-    if (new_state == LOW){
-      send485("Button pressed");
-    } else {
-      send485("Button released");
-    }
-  }
-}

examples/SendOnButton/SendOnButton.ino

@@ -0,0 +1,39 @@
+/*
+ This sketch demonstrates, how to use the SoftRS485 library.
+ It listens on the RS485 network bus.
+ When the button is pressed, it sends some messages on the bus.
+ */
+
+#include <SoftRS485.h>
+
+#define BUTTON 7
+
+boolean state = LOW;
+
+void setup() {
+  Serial.begin(115200);
+  Serial.println(F("This is ReceiveDemo, version 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
+  pinMode(BUTTON,INPUT_PULLUP);
+}
+
+void loop(){
+  if (available485()) Serial.println("Received: "+get485message());
+  
+  boolean new_state = digitalRead(BUTTON);
+  if (new_state != state){
+    if (state){
+      for (int i=1; i<16; i++){
+        String s = "Button pressed   "+String(i);
+        send485(s.c_str());
+        delay(100);
+      }
+    } else send485("Button released!");
+    state = new_state;
+  }
+}

examples/TempSend/TempSend.ino

@@ -2,10 +2,31 @@
 #include <SoftRS485.h>
 #include <SimpleDHT.h>
 
+// TempSend
+// 
+// This is an example for sending DHT11 measures over an RS485 multimaster network.
+// It makes use of an internal timer to periodically query values from an DHT11 sensor, connected at pin 6:
+//
+// This timer is set up in the method "setupTimer".
+// The _interrupt service routine_ (ISR) just sets a flag _readSample_, which is checked in the main loop.
+// If the _readSample_ flag is set, a measure is fetched from the sensor and transmitted via _send485_ call.
+// 
+// The main loop also listens for incoming messages and echos them on the Serial console.
+
 int pinDHT11 = 6;
 int count = 0;
+String s;
+boolean readSample = false;
+
+SimpleDHT11 dht11(pinDHT11); // Sensor connected on pin 6
 
-SimpleDHT11 dht11(pinDHT11);
+void setupTimer(){
+  TCCR1A = 0;           // Init Timer1A
+  TCCR1B = 0;           // Init Timer1B
+  TCCR1B |= B00000101;  // Prescaler = 1024
+  OCR1A = 31250;        // Timer Compare1A Register
+  TIMSK1 |= B00000010;  // Enable Timer COMPA Interrupt
+}
 
 void setup() {
   Serial.begin(115200);
@@ -15,21 +36,32 @@ 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!")) {}
+  
+  while (!send485("Hello world!")) {} // send hello on network
+  setupTimer(); // start timer for DHT 11 measurements
+}
+
+/* Interrupt service routine – sets _readSample_ flag */
+ISR(TIMER1_COMPA_vect){
+  OCR1A += 31250; // Advance The COMPA Register
+  readSample = true;
 }
 
 void loop() {
-  delay(2000);
-  // 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;
+  if (available485()) Serial.println("Received: "+get485message());
+  
+  if (readSample){ // it is time to take a reading!
+    readSample = false;
+    byte temperature = 0;
+    byte humidity = 0;
+    int err = SimpleDHTErrSuccess;
+    count++;
+    s = "Sample "+String(count);
+    if ((err = dht11.read(&temperature, &humidity, NULL)) != SimpleDHTErrSuccess) {
+      s += " failed, err="+String(SimpleDHTErrCode(err))+","+String(SimpleDHTErrDuration(err));
+    } else {    
+      s += " ok:   "+ String(temperature)+" *C, "+String(humidity)+"% rel";
+    }
+    while (!send485(s.c_str())) { /* repeat until successfull */ }
   }
-  count++;
-  String s = "Sample "+String(count)+" ok:    "+ String(temperature)+" *C, "+String(humidity)+"% rel";
-  send485(s.c_str());
 }