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CommandStation-EX/SSD1306Ascii.cpp
Neil McKechnie 79763a3bb8
SH1106 OLED Display Offset Fix (#169)
Correct display offset for SH1106.  The SH1106 supports 132 columns but most displays use 128 column OLED, connected to the middle columns 2-129.
2021-06-10 11:24:44 -04:00

109 lines
4.4 KiB
C++

/* Based on Arduino SSD1306Ascii Library, Copyright (C) 2015 by William Greiman
* Modifications (C) 2021 Neil McKechnie
*
* This Library 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, either version 3 of the License, or
* (at your option) any later version.
*
* This Library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the Arduino SSD1306Ascii Library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include "SSD1306Ascii.h"
#include "I2CManager.h"
#include "FSH.h"
// Maximum number of bytes we can send per transmission is 32.
const uint8_t SSD1306AsciiWire::blankPixels[16] =
{0x40, // First byte specifies data mode
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
//==============================================================================
// SSD1306AsciiWire Method Definitions
//------------------------------------------------------------------------------
void SSD1306AsciiWire::clear() {
clear(0, displayWidth() - 1, 0, displayRows() - 1);
}
//------------------------------------------------------------------------------
void SSD1306AsciiWire::clear(uint8_t columnStart, uint8_t columnEnd,
uint8_t rowStart, uint8_t rowEnd) {
const int maxBytes = sizeof(blankPixels); // max number of bytes sendable over Wire
// Ensure only rows on display will be cleared.
if (rowEnd >= displayRows()) rowEnd = displayRows() - 1;
for (uint8_t r = rowStart; r <= rowEnd; r++) {
setCursor(columnStart, r); // Position at start of row to be erased
for (uint8_t c = columnStart; c <= columnEnd; c += maxBytes-1) {
uint8_t len = min((uint8_t)(columnEnd-c+1), maxBytes-1) + 1;
I2CManager.write(m_i2cAddr, blankPixels, len); // Write up to 15 blank columns
}
}
}
//------------------------------------------------------------------------------
void SSD1306AsciiWire::begin(const DevType* dev, uint8_t i2cAddr) {
m_i2cAddr = i2cAddr;
m_col = 0;
m_row = 0;
#ifdef __AVR__
const uint8_t* table = (const uint8_t*)pgm_read_word(&dev->initcmds);
#else // __AVR__
const uint8_t* table = dev->initcmds;
#endif // __AVR
uint8_t size = readFontByte(&dev->initSize);
m_displayWidth = readFontByte(&dev->lcdWidth);
m_displayHeight = readFontByte(&dev->lcdHeight);
m_colOffset = readFontByte(&dev->colOffset);
I2CManager.write_P(m_i2cAddr, table, size);
}
//------------------------------------------------------------------------------
void SSD1306AsciiWire::setContrast(uint8_t value) {
I2CManager.write(m_i2cAddr, 2,
0x00, // Set to command mode
SSD1306_SETCONTRAST, value);
}
//------------------------------------------------------------------------------
void SSD1306AsciiWire::setCursor(uint8_t col, uint8_t row) {
if (row < displayRows() && col < m_displayWidth) {
m_row = row;
m_col = col + m_colOffset;
I2CManager.write(m_i2cAddr, 4,
0x00, // Set to command mode
SSD1306_SETLOWCOLUMN | (m_col & 0XF),
SSD1306_SETHIGHCOLUMN | (m_col >> 4),
SSD1306_SETSTARTPAGE | m_row);
}
}
//------------------------------------------------------------------------------
void SSD1306AsciiWire::setFont(const uint8_t* font) {
m_font = font;
m_fontFirstChar = readFontByte(m_font + FONT_FIRST_CHAR);
m_fontCharCount = readFontByte(m_font + FONT_CHAR_COUNT);
}
//------------------------------------------------------------------------------
size_t SSD1306AsciiWire::write(uint8_t ch) {
const uint8_t* base = m_font + FONT_WIDTH_TABLE;
if (ch < m_fontFirstChar || ch >= (m_fontFirstChar + m_fontCharCount))
return 0;
ch -= m_fontFirstChar;
base += fontWidth * ch;
uint8_t buffer[1+fontWidth+letterSpacing];
buffer[0] = 0x40; // set SSD1306 controller to data mode
uint8_t bufferPos = 1;
// Copy character pixel columns
for (uint8_t i = 0; i < fontWidth; i++)
buffer[bufferPos++] = readFontByte(base++);
// Add blank pixels between letters
for (uint8_t i = 0; i < letterSpacing; i++)
buffer[bufferPos++] = 0;
// Write the data to I2C display
I2CManager.write(m_i2cAddr, buffer, bufferPos);
return 1;
}