File content as of revision 3:a8f72d4864e6:

/* NeatGUI Library
 * Copyright (c) 2013 Neil Thiessen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "SSD1306_I2C.h"

SSD1306_I2C::SSD1306_I2C(PinName sda, PinName scl, Address addr) : Display(128, 64), m_I2C(sda, scl), m_ADDR((int)addr)
{
    //Set the I2C frequency to 400kHz
    m_I2C.frequency(400000);
}

bool SSD1306_I2C::open()
{
    //Probe for the SSD1306 using a Zero Length Transfer
    if (!m_I2C.write(m_ADDR, NULL, 0)) {
        //Init sequence for 128x64 OLED module
        writeCommand(CMD_DISPLAYOFF);
        writeCommand(CMD_SETDISPLAYCLOCKDIV);
        writeCommand(0x80);
        writeCommand(CMD_SETMULTIPLEX);
        writeCommand(0x3F);
        writeCommand(CMD_SETDISPLAYOFFSET);
        writeCommand(0x0);
        writeCommand(CMD_SETSTARTLINE | 0x0);
        writeCommand(CMD_CHARGEPUMP);
        writeCommand(CMD_CHARGEPUMPON);
        writeCommand(CMD_MEMORYMODE);
        writeCommand(0x00);
        writeCommand(CMD_SEGREMAP | 0x1);
        writeCommand(CMD_COMSCANDEC);
        writeCommand(CMD_SETCOMPINS);
        writeCommand(0x12);
        writeCommand(CMD_SETCONTRAST);
        writeCommand(0xCF);
        writeCommand(CMD_SETPRECHARGE);
        writeCommand(0xF1);
        writeCommand(CMD_SETVCOMDETECT);
        writeCommand(0x40);
        writeCommand(CMD_DISPLAYALLON_RESUME);
        writeCommand(CMD_NORMALDISPLAY);

        //Return success
        return true;
    } else {
        //Return failure
        return false;
    }
}

void SSD1306_I2C::flush()
{
    //Select low col 0, hi col 0, line 0
    writeCommand(CMD_SETLOWCOLUMN | 0x0);
    writeCommand(CMD_SETHIGHCOLUMN | 0x0);
    writeCommand(CMD_SETSTARTLINE | 0x0);

    //Make sure the first byte in the buffer is the control byte
    m_Buffer[0] = CONTROL_DATA;

    //Write the buffer
    m_I2C.write(m_ADDR, m_Buffer, 1025);
}

Display::State SSD1306_I2C::state()
{
    //Return the base class's state
    return Display::state();
}

void SSD1306_I2C::state(State s)
{
    //Check what the requested state is
    if (s == Display::DISPLAY_ON) {
        //Turn the display on
        writeCommand(CMD_DISPLAYON);
    } else if (s == Display::DISPLAY_OFF) {
        //Turn the display off
        writeCommand(CMD_DISPLAYOFF);
    }

    //Update the base class
    Display::state(s);
}

void SSD1306_I2C::drawPixel(int x, int y, unsigned int c)
{
    //Range check the pixel
    if ((x < 0) || (x >= width()) || (y < 0) || (y >= height()))
        return;

    //Make sure the color is fully opaque
    if ((c >> 24) != 255)
        return;

    //Determine the pixel byte index
    unsigned short byteIndex = x + (y / 8) * width();

    //HACK: Fix the whole 1025 byte i2c buffer thing
    byteIndex++;

    //Set or clear the pixel
    if ((c & 0x00FFFFFF) > 0)
        m_Buffer[byteIndex] |= (1 << (y % 8));
    else
        m_Buffer[byteIndex] &= ~(1 << (y % 8));
}

void SSD1306_I2C::writeCommand(char command)
{
    //Create a temporary buffer
    char buff[2];

    //Load the control byte and 8-bit command
    buff[0] = CONTROL_COMMAND;
    buff[1] = command;

    //Write the command
    m_I2C.write(m_ADDR, buff, 2);
}

void SSD1306_I2C::writeData(char data)
{
    //Create a temporary buffer
    char buff[2];

    //Load the control byte and 8-bit data
    buff[0] = CONTROL_DATA;
    buff[1] = data;

    //Write the data
    m_I2C.write(m_ADDR, buff, 2);
}