G0ORX_FrontPanel.cpp

/*********************************************************************************************
 * 
 * G0ORX Front Panel
 * 
 * (c) John Melton, G0ORX, 20 August 2022
 * 
 * This software is made available under the GNU GPL v3 license agreement.
 * 
 */

/*
 * The front panel consists of 2 MCP23017 16 bit I/O port expanders.
 * Each device is controlled through the I2C bus and the devices use the I2C address 0x20 and 0x21.
 * 
 * The device at 0x20 has switches 1..16 connected to it.
 * 
 * The device at 0x21 has the switches 17 and 18, encoder 1..4 switches, encoder 1..4 A and B and 2 output LEDS.
 * 
 * An interrupt is generated when an I/O port input changes state.
 *   
 * The device at 0x20 generates an interrupt on pin 39 (pulls it low) - Pin 7 of the IDC connector.
 * The device at 0x21 generates an interrupt on pin 17 (pulls it low) - Pin 9 of the IDC connector.
 * 
 * The IDC connector is connected to Tune/Filter IDC connector of the Main Board.
 *
 * Note: BOURN encoders have their A/B pins reversed compared to cheaper encoders.
 * 
 */

#ifndef BEENHERE
#include "SDT.h"
#endif

#ifdef G0ORX_FRONTPANEL

#define DEBOUNCE_DELAY 10

// comment out to swap A and B if using cheap encoders
#define BOURN_ENCODERS

#define e1 volumeEncoder
#define e2 filterEncoder
#define e3 tuneEncoder
#define e4 fineTuneEncoder

G0ORX_Rotary volumeEncoder;
G0ORX_Rotary filterEncoder;
G0ORX_Rotary tuneEncoder;
G0ORX_Rotary fineTuneEncoder;

enum {
  PRESSED,
  RELEASED
};

#define MCP23017_ADDR_1 0x20
#define MCP23017_ADDR_2 0x21

#define INT_PIN_1 14
#define INT_PIN_2 15

static Adafruit_MCP23X17 mcp1;
static volatile bool interrupted1 = false;

static Adafruit_MCP23X17 mcp2;
static volatile bool interrupted2 = false;

int G0ORXButtonPressed = -1;

#define LED1 0
#define LED2 1

#define LED_1_PORT 6
#define LED_2_PORT 7

FASTRUN
static void interrupt1() {
  uint8_t pin;
  uint8_t state;
  __disable_irq();
  while((pin = mcp1.getLastInterruptPin())!=MCP23XXX_INT_ERR) {
    state = mcp1.digitalRead(pin);
    if (state == PRESSED) {
      G0ORXButtonPressed = pin;
    } else {
      //buttonReleased(pin1);
    }
  }
  __enable_irq();
}

FASTRUN
static void interrupt2() {
  uint8_t pin;
  uint8_t state = 0x00;
  uint8_t a_state;
  uint8_t b_state;

  __disable_irq();
  pin = mcp2.getLastInterruptPin();
  Debug(String(__FUNCTION__)+": "+String(pin));
  a_state = mcp2.readGPIOA();
  b_state = mcp2.readGPIOB();
  switch(pin) {
    case 8:
    case 9:
      state = b_state & 0x03;
      break;
    case 10:
    case 11:
      state = (b_state >> 2) & 0x03;
      break;
    case 12:
    case 13:
      state = (b_state >> 4) & 0x03;
      break;
    case 14:
    case 15:
      state = (b_state >> 6) & 0x03;
      break;
  }

  // process the state
  switch(pin) {
    case 8:
      e1.updateA(state);
      EncoderVolume();
      break;
    case 9:
      e1.updateB(state);
      EncoderVolume();
      break;
    case 10:
      e2.updateA(state);
      EncoderFilter();
      break;
    case 11:
      e2.updateB(state);
      EncoderFilter();
      break;
    case 12:
      e3.updateA(state);
      break;
    case 13:
      e3.updateB(state);
      break;
    case 14:
      e4.updateA(state);
      EncoderFineTune();
      break;
    case 15:
      e4.updateB(state);
      EncoderFineTune();
      break;
    case 0:
    case 1:
    case 2:
    case 3:
    case 4:
    case 5:
      state = (a_state >> pin) & 0x01;
      Debug(String(__FUNCTION__)+": "+String(pin)+"="+String(state));
      if (state == PRESSED) {
        G0ORXButtonPressed = (pin+16);
      } else {
        //buttonReleased(pin2+16);
      }
      break;
    default:
      // 255 sometimes caused by switch bounce
      //Debug(String(__FUNCTION__)+": "+String(pin)+"!");
      break;
  }
  __enable_irq();
}

void FrontPanelInit() {
  bool failed=false;

  // Set Wire1 I2C bus to 1MHz and start
  //Wire1.setClock(1000000UL);
  Wire1.begin();

  if (!mcp1.begin_I2C(MCP23017_ADDR_1,&Wire1)) {
    ShowMessageOnWaterfall("MCP23017 not found at 0x"+String(MCP23017_ADDR_1,HEX));
    failed=true;
  }

  if (!mcp2.begin_I2C(MCP23017_ADDR_2,&Wire1)) {
    ShowMessageOnWaterfall("MCP23017 not found at 0x"+String(MCP23017_ADDR_2,HEX));
    failed=true;
  }

  if(failed) return;

  // setup the mcp23017 devices
  mcp1.setupInterrupts(true, true, LOW);
  mcp2.setupInterrupts(true, true, LOW);

  // setup switches 1..16
  for (int i = 0; i < 16; i++) {
    mcp1.pinMode(i, INPUT_PULLUP);
    mcp1.setupInterruptPin(i, CHANGE);
  }

  // setup switches 17..18 and Encoder switches 1..4 (note 6 and 7 are output LEDs)
  for (int i = 0; i < 6; i++) {
    mcp2.pinMode(i, INPUT_PULLUP);
    mcp2.setupInterruptPin(i, CHANGE);
  }

  mcp2.pinMode(LED_1_PORT, OUTPUT);  // LED1
  mcp2.digitalWrite(LED_1_PORT, LOW);
  mcp2.pinMode(LED_2_PORT, OUTPUT);  // LED2
  mcp2.digitalWrite(LED_2_PORT, LOW);   

  // setup encoders 1..4 A and B
  for (int i = 8; i < 16; i++) {
    mcp2.pinMode(i, INPUT_PULLUP);
    mcp2.setupInterruptPin(i, CHANGE);
  }

  // clear interrupts
  mcp1.readGPIOAB(); // ignore any return value
  mcp2.readGPIOAB(); // ignore any return value

  pinMode(INT_PIN_1, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(INT_PIN_1), interrupt1, LOW);

  pinMode(INT_PIN_2, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(INT_PIN_2), interrupt2, LOW);
  
}

FASTRUN
void FrontPanelSetLed(int led, uint8_t state) {
  Debug(String(__FUNCTION__)+": led="+String(led)+" state="+String(state));
  switch (led) {
    case LED1:
      mcp2.digitalWrite(LED_1_PORT, state);
      break;
    case LED2:
      mcp2.digitalWrite(LED_2_PORT, state);
      break;
  }
}
#endif