Zumo32U4OLED.h

// Copyright (C) Pololu Corporation.  See www.pololu.com for details.
 
#pragma once
 
#include <Arduino.h>
#include <FastGPIO.h>
#include <USBPause.h>
#include <PololuSH1106Main.h>
#include <util/delay.h>
 
// This asm inside the macro below is an optimized version of
//   FastGPIO::Pin<mosPin>::setOutputValue(d >> b & 1);
// It prevents the compiler from using slow branches to implement the
// conditional logic, and also ensures that the writing speed doesn't depend
// on the data.
#define _P3PP_OLED_SEND_BIT(b) \
  FastGPIO::Pin<clkPin>::setOutputValueLow(); \
  asm volatile( \
    "sbrc %2, %3\n" "sbi %0, %1\n" \
    "sbrs %2, %3\n" "cbi %0, %1\n" \
    : : \
    "I" (FastGPIO::pinStructs[mosPin].portAddr - __SFR_OFFSET), \
    "I" (FastGPIO::pinStructs[mosPin].bit), \
    "r" (d), \
    "I" (b)); \
  FastGPIO::Pin<clkPin>::setOutputValueHigh();
 
class Zumo32U4OLEDCore
{
  // Pin assignments
  static const uint8_t clkPin = 1, mosPin = IO_D5, resPin = 0, dcPin = 17;
 
public:
  void initPins()
  {
    FastGPIO::Pin<clkPin>::setOutputLow();
  }
 
  void reset()
  {
    FastGPIO::Pin<resPin>::setOutputLow();
    _delay_us(10);
    FastGPIO::Pin<resPin>::setOutputHigh();
    _delay_us(10);
  }
 
  void sh1106TransferStart()
  {
    // From https://github.com/pololu/usb-pause-arduino/blob/master/USBPause.h:
    // Disables USB interrupts because the Arduino USB interrupts use some of
    // the OLED pins.
    savedUDIEN = UDIEN;
    UDIEN = 0;
    savedUENUM = UENUM;
    UENUM = 0;
    savedUEIENX0 = UEIENX;
    UEIENX = 0;
 
    savedStateMosi = FastGPIO::Pin<mosPin>::getState();
    savedStateDc = FastGPIO::Pin<dcPin>::getState();
 
    FastGPIO::Pin<mosPin>::setOutputLow();
  }
 
  void sh1106TransferEnd()
  {
    FastGPIO::Pin<mosPin>::setState(savedStateMosi);
    FastGPIO::Pin<dcPin>::setState(savedStateDc);
 
    // From https://github.com/pololu/usb-pause-arduino/blob/master/USBPause.h
    UENUM = 0;
    UEIENX = savedUEIENX0;
    UENUM = savedUENUM;
    UDIEN = savedUDIEN;
  }
 
  void sh1106CommandMode()
  {
    FastGPIO::Pin<dcPin>::setOutputLow();
  }
 
  void sh1106DataMode()
  {
    FastGPIO::Pin<dcPin>::setOutputHigh();
  }
 
  void sh1106Write(uint8_t d)
  {
    _P3PP_OLED_SEND_BIT(7);
    _P3PP_OLED_SEND_BIT(6);
    _P3PP_OLED_SEND_BIT(5);
    _P3PP_OLED_SEND_BIT(4);
    _P3PP_OLED_SEND_BIT(3);
    _P3PP_OLED_SEND_BIT(2);
    _P3PP_OLED_SEND_BIT(1);
    _P3PP_OLED_SEND_BIT(0);
  }
 
private:
  uint8_t savedStateMosi, savedStateDc;
  uint8_t savedUDIEN, savedUENUM, savedUEIENX0;
};
 
class Zumo32U4OLED : public PololuSH1106Main<Zumo32U4OLEDCore>
{
};