Configurable CPPM output pin

README.md

@@ -2,12 +2,14 @@
 
 This sketch allows connecting a [Saitek X52](http://www.saitek.com/uk/prod/x52.html) or [Saitek X52 Pro](http://www.saitek.com/uk/prod/x52pro.html) to an [Arduino](https://www.arduino.cc/en/Main/ArduinoBoardUno) with a [USB Host Shield](https://www.arduino.cc/en/Main/ArduinoUSBHostShield). It uses the [USB_Host_Shield_2.0 Library](https://github.com/felis/USB_Host_Shield_2.0).
 
-A CPPM signal is generated on a configurable pin (4 by default, can be changed in `cppm.h`).
+A CPPM signal is generated on a configurable pin and can be fed into a transmitter module or directly into a flight controller.
 
-It includes code to interface with the Multi-Function-Display on the Joystick to display text and change the LED and background lighting.
+Using the Multi-Function-Display on the Joystick, every config option can be changed. These values can be stored on the EEPROM and will be loaded on every start.
 
 I'm connecting the Arduino to the [FrSky DHT module](http://www.frsky-rc.com/product/pro.php?pro_id=7) in my modified transmitter to control my Tricopter.
 
+A modified (ie. non-inverted) FrSky Host Telemetry Port (D-Port) can be connected to the hardware serial port of the Arduino so the Telemetry data (link quality and voltages) will be displayed on the Multi-Function-Display of the joystick.
+
 ## License
 
 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.

Saitek-X52-PPM.ino

@@ -22,10 +22,12 @@
 #include "frsky.h"
 #include "config.h"
 
-#define ENABLE_SERIAL_PORT
+#define ENABLE_SERIAL_PORT 9600
 //#define DEBUG_OUTPUT Serial
 //#define DEBUG_MFD_UPTIME
 
+#define LED_STATUS_PIN 13
+
 USB usb;
 USBHub hub(&usb);
 HIDUniversal hid(&usb);
@@ -65,27 +67,27 @@ void statusCallback(uint8_t a1, uint8_t a2, uint8_t q1, uint8_t q2) {
 
 void setup() {
 #ifdef ENABLE_SERIAL_PORT
-    Serial.begin(115200);
+    Serial.begin(ENABLE_SERIAL_PORT);
 #endif
 
 #ifdef DEBUG_OUTPUT
     DEBUG_OUTPUT.println("Start");
 #endif
 
-    pinMode(13, OUTPUT);
-    digitalWrite(13, LOW);
+    pinMode(LED_STATUS_PIN, OUTPUT);
+    digitalWrite(LED_STATUS_PIN, LOW);
 
     eepromRead();
 
     if (usb.Init() == -1) {
-        digitalWrite(13, HIGH);
+        digitalWrite(LED_STATUS_PIN, HIGH);
 #ifdef DEBUG_OUTPUT
         DEBUG_OUTPUT.println("OSC did not start.");
 #endif
     }
 
     if (!hid.SetReportParser(0, &joy)) {
-        digitalWrite(13, HIGH);
+        digitalWrite(LED_STATUS_PIN, HIGH);
 #ifdef DEBUG_OUTPUT
         DEBUG_OUTPUT.println("Error adding report parser.");
 #endif
@@ -93,7 +95,7 @@ void setup() {
 
     CPPM::instance().init();
     frsky.setDataHandler(&statusCallback);
-    wdt_enable(WDTO_500MS);
+    wdt_enable(WDTO_1S);
 }
 
 void init_joystick() {

config.cpp

@@ -6,6 +6,7 @@
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation, version 2.
  */
+
 #include <EEPROM.h>
 #include "cppm.h"
 #include "events.h"
@@ -67,11 +68,13 @@ static uint8_t fromEEPROM(ConfigData& data) {
 
 void eepromRead() {
     ConfigData data;
+
     if (fromEEPROM(data) != 0) {
         data.channels = DEFAULT_CHANNELS;
         data.frameLength = DEFAULT_FRAME_LENGTH;
         data.pulseLength = DEFAULT_PULSE_LENGTH;
         data.inverted = DEFAULT_INVERT_STATE;
+        data.cppmPin = CPPM_OUTPUT_PIN_DEFAULT;
         for (uint8_t i = 0; i < CHANNELS_MAX; i++) {
             data.invert[i] = 0;
             data.minimum[i] = CHANNEL_MINIMUM_VALUE;
@@ -79,12 +82,14 @@ void eepromRead() {
             data.trim[i] = 0;
         }
 
+        // Should be correct for every device
+        data.invert[CHANNEL_THROTTLE] = 1;
+        data.invert[CHANNEL_PITCH] = 1;
+
         /*
          * Default values to match my personal setup.
          * Can be changed using the on-screen menu.
          */
-        data.invert[CHANNEL_THROTTLE] = 1;
-        data.invert[CHANNEL_PITCH] = 1;
         data.minimum[CHANNEL_THROTTLE] = 1010;
         data.maximum[CHANNEL_THROTTLE] = 1950;
         data.minimum[CHANNEL_ROLL] = 1050;
@@ -103,6 +108,7 @@ void eepromRead() {
     CPPM::instance().setFrameLength(data.frameLength);
     CPPM::instance().setPulseLength(data.pulseLength);
     CPPM::instance().setInvert(data.inverted);
+    CPPM::instance().setOutput(data.cppmPin);
     for (uint8_t i = 0; i < CHANNELS_MAX; i++) {
         joyCPPM.setInvert(i, data.invert[i]);
         joyCPPM.setMinimum(i, data.minimum[i]);
@@ -113,16 +119,19 @@ void eepromRead() {
 
 void eepromWrite() {
     ConfigData data;
+
     data.channels = CPPM::instance().getChannels();
     data.frameLength = CPPM::instance().getFrameLength();
     data.pulseLength = CPPM::instance().getPulseLength();
     data.inverted = CPPM::instance().getInvert();
+    data.cppmPin = CPPM::instance().getOutput();
     for (uint8_t i = 0; i < CHANNELS_MAX; i++) {
         data.invert[i] = joyCPPM.getInvert(i);
         data.minimum[i] = joyCPPM.getMinimum(i);
         data.maximum[i] = joyCPPM.getMaximum(i);
         data.trim[i] = joyCPPM.getTrim(i);
     }
+
     toEEPROM(data);
 }
 

config.h

@@ -12,7 +12,7 @@
 
 #include <stdint.h>
 
-#define CPPM_OUTPUT_PIN 4
+#define CPPM_OUTPUT_PIN_DEFAULT 4
 #define CHANNEL_MINIMUM_VALUE 1000
 #define CHANNEL_DEFAULT_VALUE 1500
 #define CHANNEL_MAXIMUM_VALUE 2000
@@ -32,11 +32,11 @@ enum RxChannels {
 };
 
 // Increase string number when struct changes!
-#define CONFIG_VERSION "USBCPPM-01"
+#define CONFIG_VERSION "USBCPPM-02"
 #define CONFIG_VERSION_LENGTH (sizeof(CONFIG_VERSION) - 1)
 
 struct ConfigData {
-    uint16_t channels, frameLength, pulseLength, inverted;
+    uint16_t channels, frameLength, pulseLength, inverted, cppmPin;
     uint16_t minimum[CHANNELS_MAX];
     uint16_t maximum[CHANNELS_MAX];
     uint16_t invert[CHANNELS_MAX];

cppm.cpp

@@ -11,6 +11,7 @@
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation, version 2.
  */
+
 #include <Arduino.h>
 #include "cppm.h"
 
@@ -30,8 +31,8 @@ void CPPM::init(void) {
         data[i] = CHANNEL_DEFAULT_VALUE;
     }
 
-    pinMode(CPPM_OUTPUT_PIN, OUTPUT);
-    digitalWrite(CPPM_OUTPUT_PIN, CPPM::inst->onState ? LOW : HIGH);
+    pinMode(output, OUTPUT);
+    digitalWrite(output, CPPM::inst->onState ? LOW : HIGH);
 
     cli();
     TCCR1A = 0; // set entire TCCR1 register to 0
@@ -43,6 +44,14 @@ void CPPM::init(void) {
     sei();
 }
 
+void CPPM::setOutput(uint8_t i) {
+    digitalWrite(output, LOW);
+    pinMode(output, INPUT);
+    output = i;
+    pinMode(output, OUTPUT);
+    digitalWrite(output, CPPM::inst->onState ? LOW : HIGH);
+}
+
 void CPPM::copy(uint16_t* d) {
 #ifdef DEBUG_OUTPUT
     DEBUG_OUTPUT.println("New CPPM data!");
@@ -63,12 +72,12 @@ ISR(TIMER1_COMPA_vect) {
     TCNT1 = 0;
     if (CPPM::inst->state) {
         // start pulse
-        digitalWrite(CPPM_OUTPUT_PIN, CPPM::inst->onState ? HIGH : LOW);
+        digitalWrite(CPPM::inst->output, CPPM::inst->onState ? HIGH : LOW);
         OCR1A = CPPM::inst->pulseLength << 1;
         CPPM::inst->state = 0;
     } else {
         // end pulse and calculate when to start the next pulse
-        digitalWrite(CPPM_OUTPUT_PIN, CPPM::inst->onState ? LOW : HIGH);
+        digitalWrite(CPPM::inst->output, CPPM::inst->onState ? LOW : HIGH);
         CPPM::inst->state = 1;
         if (CPPM::inst->currentChannel >= CPPM::inst->channels) {
             CPPM::inst->currentChannel = 0;

cppm.h

@@ -44,15 +44,20 @@ class CPPM {
     inline uint8_t getInvert() { return !onState; }
     inline void setInvert(uint8_t i) { onState = !i; }
 
+    inline uint8_t getOutput() { return output; }
+    void setOutput(uint8_t i);
+
   private:
     CPPM() : channels(DEFAULT_CHANNELS), frameLength(DEFAULT_FRAME_LENGTH),
-            pulseLength(DEFAULT_PULSE_LENGTH), onState(!DEFAULT_INVERT_STATE) { }
+            pulseLength(DEFAULT_PULSE_LENGTH), onState(!DEFAULT_INVERT_STATE),
+            output(CPPM_OUTPUT_PIN_DEFAULT) { }
     CPPM(CPPM&) { }
 
     volatile uint16_t channels;
     volatile uint16_t frameLength; // PPM frame length in microseconds (1ms = 1000µs)
     volatile uint16_t pulseLength;
     volatile uint8_t onState; // polarity of the pulses: 1 is positive, 0 is negative
+    volatile uint8_t output;
 
     volatile uint16_t data[CHANNELS_MAX];
     volatile uint8_t state;

events.h

@@ -118,6 +118,7 @@ class JoystickEventsButtons : public JoystickEvents {
         EDIT_FRAME_LENGTH,
         EDIT_PULSE_LENGTH,
         EDIT_INVERT,
+        EDIT_CPPM_PIN,
         EDIT_MIN_ROLL,
         EDIT_MAX_ROLL,
         EDIT_MIN_PITCH,

events_buttons.cpp

@@ -54,7 +54,7 @@ void JoystickEventsButtons::printMenu() {
     static const uint8_t mainMenuCount = sizeof(mainMenu) / sizeof(mainMenu[0]);
 
     static const char* cppmMenu[] = {
-        "Channels", "Frame Length", "Pulse Length", "Invert", "Main Menu"
+        "Channels", "Frame Length", "Pulse Length", "Invert", "Output Pin", "Main Menu"
     };
     static const uint8_t cppmMenuCount = sizeof(cppmMenu) / sizeof(cppmMenu[0]);
 
@@ -90,6 +90,8 @@ void JoystickEventsButtons::printMenu() {
         printValue(MIN_PULSE_LENGTH, MAX_PULSE_LENGTH, cppmMenu[2]);
     } else if (state == EDIT_INVERT) {
         printValue(0, 1, cppmMenu[3]);
+    } else if (state == EDIT_CPPM_PIN) {
+        printValue(0, 13, cppmMenu[4]);
     } else if ((state >= EDIT_INVERT_ROLL) && (state <= EDIT_INVERT_AUX2)) {
         uint8_t index = state - EDIT_INVERT_ROLL;
         printValue(0, 1, (String("Invert ") + axisMenu[index]).c_str());
@@ -252,6 +254,9 @@ void JoystickEventsButtons::OnButtonDown(uint8_t but_id) {
                 state = EDIT_INVERT;
                 value = CPPM::instance().getInvert();
             } else if (index == 4) {
+                state = EDIT_CPPM_PIN;
+                value = CPPM::instance().getOutput();
+            } else if (index == 5) {
                 state = MAINMENU;
                 index = 0;
             }
@@ -267,6 +272,9 @@ void JoystickEventsButtons::OnButtonDown(uint8_t but_id) {
         } else if (state == EDIT_INVERT) {
             CPPM::instance().setInvert(value);
             state = CPPMMENU;
+        } else if (state == EDIT_CPPM_PIN) {
+            CPPM::instance().setOutput(value);
+            state = CPPMMENU;
         } else if (state == EDIT_INVERT_ROLL) {
             joyCPPM.setInvert(CHANNEL_ROLL, value);
             state = INVERTAXISMENU;