Extra inputs for Devo Tx's

// Devo 7e PPM input
// For use with Arduino Nano V3.0
// Based on sketch by Ian Johnston

// Analog pin assignments
int AI_Pin_A1 = 2;    // potentiometer #1 pin
int AI_Pin_A2 = 3;    // potentiometer #2 pin
int AI_Raw_A1;        // Analog In raw var - 0->1023....
int AI_Raw_A2;
int A1_uS = 750;      // potentiometer #1 us
int A2_uS = 750;      // potentiometer #2 us
int sw1_uS = 750;     // 3-way switch #1 us
int sw2_uS = 750;     // 3-way switch #2 us
int sw3_uS = 750;     // 2-way switch #1 us
int sw4_uS = 750;     // 2-way switch #2 us


int Fixed_uS = 300;       // PPM frame fixed LOW phase
int pulseMin = 750;       // pulse minimum width minus start in uS
int pulseMax = 1700;      // pulse maximum width in uS

// Digital pin assignments
int outPinPPM = 10;     // PPM out
int inPinD2 = 2;        // 3-way switch #1 pin for position 1. Positions 1 and 3 combine for middle position.
int inPinD3 = 3;        // 3-way switch #1 pin for position 3
int inPinD4 = 4;        // 3-way switch #2 pin for position 1
int inPinD5 = 5;        // 3-way switch #2 pin for position 3
int inPinD6 = 6;        // 2-way switch #1 pin for position 1
int inPinD7 = 7;        // 2-way switch #2 pin for position 1

ISR(TIMER1_COMPA_vect) {
    ppmoutput(); // Jump to ppmoutput subroutine
}

void setup() {
  
  pinMode(outPinPPM, OUTPUT);   // sets the digital pin as output
  pinMode(inPinD2, INPUT);      // sets the digital pin as input
  digitalWrite(inPinD2, HIGH);  // turn on pull-up resistor
  pinMode(inPinD3, INPUT);
  digitalWrite(inPinD3, HIGH);
  pinMode(inPinD4, INPUT);
  digitalWrite(inPinD4, HIGH);
  pinMode(inPinD5, INPUT);
  digitalWrite(inPinD5, HIGH);
  pinMode(inPinD6, INPUT);
  digitalWrite(inPinD6, HIGH);
  pinMode(inPinD7, INPUT);
  digitalWrite(inPinD7, HIGH);
  
   // Setup timer
  TCCR1A = B00110001; // Compare register B used in mode '3'
  TCCR1B = B00010010; // WGM13 and CS11 set to 1
  TCCR1C = B00000000; // All set to 0
  TIMSK1 = B00000010; // Interrupt on compare B
  TIFR1  = B00000010; // Interrupt on compare B
  OCR1A = 22000; // 22mS PPM output refresh
  OCR1B = 1000;
}

void ppmoutput() { // PPM output sub routine

 // Channel 1 - Analog 1
  digitalWrite(outPinPPM, LOW);
  delayMicroseconds(Fixed_uS);    // Hold
  digitalWrite(outPinPPM, HIGH);
  delayMicroseconds(A1_uS);  // Hold for A1_uS microseconds      

 // Channel 2 - Analog 2
  digitalWrite(outPinPPM, LOW);
  delayMicroseconds(Fixed_uS);    // Hold
  digitalWrite(outPinPPM, HIGH);
  delayMicroseconds(A2_uS); // Hold for A2_uS microseconds

// Channel 3 - 3-way switch #1
  digitalWrite(outPinPPM, LOW);
  delayMicroseconds(Fixed_uS);    // Hold
  digitalWrite(outPinPPM, HIGH);
  delayMicroseconds(sw1_uS);     // Hold for sw1_uS microseconds 

// Channel 4 - 3-way switch #2
  digitalWrite(outPinPPM, LOW);
  delayMicroseconds(Fixed_uS);    // Hold
  digitalWrite(outPinPPM, HIGH);
  delayMicroseconds(sw2_uS);     // Hold for sw2_uS microseconds

// Channel 5 - 2-way switch #1
  digitalWrite(outPinPPM, LOW);
  delayMicroseconds(Fixed_uS);    // Hold
  digitalWrite(outPinPPM, HIGH);
  delayMicroseconds(sw3_uS);     // Hold for sw3_uS microseconds

// Channel 6 - 2-way switch #2
  digitalWrite(outPinPPM, LOW);
  delayMicroseconds(Fixed_uS);    // Hold
  digitalWrite(outPinPPM, HIGH);
  delayMicroseconds(sw4_uS);     // Hold for sw4_uS microseconds

// Synchro pulse
  digitalWrite(outPinPPM, LOW);
  delayMicroseconds(Fixed_uS);    // Hold
  digitalWrite(outPinPPM, HIGH);  // Start Synchro pulse
}

void loop() { // Main loop

 // Read analog pins
   AI_Raw_A1 = analogRead(AI_Pin_A1);
   AI_Raw_A2 = analogRead(AI_Pin_A2);
   
 // Map analog inputs to PPM rates for each of the channels
   A1_uS = AI_Raw_A1 + pulseMin;
   A2_uS = AI_Raw_A2 + pulseMin;

 // Potentiometer limits
  if (A1_uS <= 750) A1_uS = 750;     // Min
  if (A1_uS >= 1625) A1_uS = 1625;   // Max   
  if (A2_uS <= 750) A2_uS = 750;
  if (A2_uS >= 1625) A2_uS = 1625;
  
// 3-way switch #1
  if (digitalRead(inPinD2) == 0) {
           sw1_uS = 750;
 }
  if ((digitalRead(inPinD2) == 1) && (digitalRead(inPinD3) == 1)) {
           sw1_uS = 1190;                 // Center us, may need to adjust this  
 }
  if (digitalRead(inPinD3) == 0) {
           sw1_uS = 1625;   
 }

// 3-way switch #2
  if (digitalRead(inPinD4) == 0) {
           sw2_uS = 750; 
 }
  if ((digitalRead(inPinD4) == 1) && (digitalRead(inPinD5) == 1)) {
           sw2_uS = 1190;                 // Center us, may need to adjust this
 }
  if (digitalRead(inPinD5) == 0) {
           sw2_uS = 1625; 
 }
 
// 2-way switch #1
  if (digitalRead(inPinD6) == 0) {
           sw2_uS = 750; 
 }
  if ((digitalRead(inPinD6) == 1) && (digitalRead(inPinD6) == 1)) {
           sw2_uS = 1625;                 
 }
 
// 2-way switch #2
  if (digitalRead(inPinD7) == 0) {
           sw2_uS = 750; 
 }
  if ((digitalRead(inPinD7) == 1) && (digitalRead(inPinD7) == 1)) {
           sw2_uS = 1625;                  
 }
}