Skip to content

Commit

Permalink
Merge pull request ThingPulse#40 from FWeinb/add-brzo-i2c-support
Browse files Browse the repository at this point in the history 
Add optional support for using brzo as i2c lib
  • Loading branch information
@squix78
squix78 committed May 27, 2016
2 parents f1f4248 + 24e44fc commit 086e891
Show file tree
Hide file tree
Showing 2 changed files with 148 additions and 86 deletions.
218 changes: 134 additions & 84 deletions SSD1306.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -50,14 +50,8 @@ bool SSD1306::init() {
}
#endif

Wire.begin(this->sda, this->sdc);

// Let's use ~700khz if ESP8266 is in 160Mhz mode
// this will be limited to ~400khz if the ESP8266 in 80Mhz mode.
Wire.setClock(700000);

reconnect();
sendInitCommands();

resetDisplay();

return true;
Expand All @@ -72,14 +66,15 @@ void SSD1306::end() {

void SSD1306::resetDisplay(void) {
clear();
#ifdef SSD1306_DOUBLE_BUFFER
memset(buffer_back, 1, DISPLAY_BUFFER_SIZE);
#endif
display();
}

void SSD1306::reconnect() {
Wire.begin(this->sda, this->sdc);
#ifdef SSD1306_USE_BRZO
brzo_i2c_setup(this->sda, this->sdc, 2000);
#else
Wire.begin(this->sda, this->sdc);
#endif
}

void SSD1306::setColor(SSD1306_COLOR color) {
Expand Down Expand Up @@ -518,100 +513,155 @@ void SSD1306::flipScreenVertically() {

void SSD1306::display(void) {
#ifdef SSD1306_DOUBLE_BUFFER
uint16_t minBoundY = 8;
uint16_t maxBoundY = 0;

uint16_t minBoundX = 129;
uint16_t maxBoundX = 0;

uint16_t x, y;

// Calculate the Y bounding box of changes
// and copy buffer[pos] to buffer_back[pos];
for (y = 0; y < 8; y++) {
for (x = 0; x < DISPLAY_WIDTH; x++) {
uint16_t pos = x + y * DISPLAY_WIDTH;
if (buffer[pos] != buffer_back[pos]) {
minBoundY = min(minBoundY, y);
maxBoundY = max(maxBoundY, y);
minBoundX = min(minBoundX, x);
maxBoundX = max(maxBoundX, x);
}
buffer_back[pos] = buffer[pos];
uint16_t minBoundY = ~0;
uint16_t maxBoundY = 0;

uint16_t minBoundX = ~0;
uint16_t maxBoundX = 0;

uint16_t x, y;

// Calculate the Y bounding box of changes
// and copy buffer[pos] to buffer_back[pos];
for (y = 0; y < 8; y++) {
for (x = 0; x < DISPLAY_WIDTH; x++) {
uint16_t pos = x + y * DISPLAY_WIDTH;
if (buffer[pos] != buffer_back[pos]) {
minBoundY = min(minBoundY, y);
maxBoundY = max(maxBoundY, y);
minBoundX = min(minBoundX, x);
maxBoundX = max(maxBoundX, x);
}
buffer_back[pos] = buffer[pos];
}
yield();
}
yield();
}

// If the minBoundY wasn't updated
// we can savely assume that buffer_back[pos] == buffer[pos]
// holdes true for all values of pos
if (minBoundY == 8) return;

sendCommand(COLUMNADDR);
sendCommand(minBoundX);
sendCommand(maxBoundX);

sendCommand(PAGEADDR);
sendCommand(minBoundY);
sendCommand(maxBoundY);

byte k = 0;
for (y = minBoundY; y <= maxBoundY; y++) {
for (x = minBoundX; x <= maxBoundX; x++) {
if (k == 0) {
Wire.beginTransmission(this->i2cAddress);
Wire.write(0x40);
// If the minBoundY wasn't updated
// we can savely assume that buffer_back[pos] == buffer[pos]
// holdes true for all values of pos
if (minBoundY == ~0) return;

sendCommand(COLUMNADDR);
sendCommand(minBoundX);
sendCommand(maxBoundX);

sendCommand(PAGEADDR);
sendCommand(minBoundY);
sendCommand(maxBoundY);

byte k = 0;
#ifdef SSD1306_USE_BRZO
uint8_t sendBuffer[17];
sendBuffer[0] = 0x40;
brzo_i2c_start_transaction(this->i2cAddress, BRZO_I2C_SPEED);
for (y = minBoundY; y <= maxBoundY; y++) {
for (x = minBoundX; x <= maxBoundX; x++) {
k++;
sendBuffer[k] = buffer[x + y * DISPLAY_WIDTH];
if (k == 16) {
brzo_i2c_write(sendBuffer, 17, true);
k = 0;
}
}
Wire.write(buffer[x + y * DISPLAY_WIDTH]);
k++;
if (k == 16) {
Wire.endTransmission();
k = 0;
yield();
}
brzo_i2c_write(sendBuffer, k + 1, true);
brzo_i2c_end_transaction();
#else
for (y = minBoundY; y <= maxBoundY; y++) {
for (x = minBoundX; x <= maxBoundX; x++) {
if (k == 0) {
Wire.beginTransmission(this->i2cAddress);
Wire.write(0x40);
}
Wire.write(buffer[x + y * DISPLAY_WIDTH]);
k++;
if (k == 16) {
Wire.endTransmission();
k = 0;
}
}
yield();
}
yield();
}

if (k != 0) {
Wire.endTransmission();
}
if (k != 0) {
Wire.endTransmission();
}
#endif

#else
// No double buffering
sendCommand(COLUMNADDR);
sendCommand(0x0);
sendCommand(0x7F);

sendCommand(PAGEADDR);
sendCommand(0x0);
sendCommand(0x7);

for (uint16_t i=0; i < DISPLAY_BUFFER_SIZE; i++) {
Wire.beginTransmission(this->i2cAddress);
Wire.write(0x40);
for (uint8_t x = 0; x < 16; x++) {
Wire.write(buffer[i]);
i++;
}
i--;
Wire.endTransmission();
}
sendCommand(COLUMNADDR);
sendCommand(0x0);
sendCommand(0x7F);

sendCommand(PAGEADDR);
sendCommand(0x0);
sendCommand(0x7);

#ifdef SSD1306_USE_BRZO
uint8_t sendBuffer[17];
sendBuffer[0] = 0x40;
brzo_i2c_start_transaction(this->i2cAddress, BRZO_I2C_SPEED);
for (uint16_t i=0; i<DISPLAY_BUFFER_SIZE; i++) {
for (uint8_t x=1; x<17; x++) {
sendBuffer[x] = buffer[i];
i++;
}
i--;
brzo_i2c_write(sendBuffer, 17, true);
yield();
}
brzo_i2c_end_transaction();
#else
byte k = 0;
for (y = minBoundY; y <= maxBoundY; y++) {
for (x = minBoundX; x <= maxBoundX; x++) {
if (k == 0) {
Wire.beginTransmission(this->i2cAddress);
Wire.write(0x40);
}
Wire.write(buffer[x + y * DISPLAY_WIDTH]);
k++;
if (k == 16) {
Wire.endTransmission();
k = 0;
}
}
yield();
}

if (k != 0) {
Wire.endTransmission();
}
#endif
#endif
}


void SSD1306::clear(void) {
memset(buffer, 0, DISPLAY_BUFFER_SIZE);
#ifdef SSD1306_DOUBLE_BUFFER
memset(buffer_back, 1, DISPLAY_BUFFER_SIZE);
#endif
}


// Private functions

void SSD1306::sendCommand(unsigned char com) {
Wire.beginTransmission(this->i2cAddress); //begin transmitting
Wire.write(0x80); //command mode
Wire.write(com);
Wire.endTransmission(); // stop transmitting
#ifdef SSD1306_USE_BRZO
uint8_t command[2] = {0x80 /* command mode */, com};
brzo_i2c_start_transaction(this->i2cAddress, BRZO_I2C_SPEED);
brzo_i2c_write(command, 2, true);
brzo_i2c_end_transaction();
#else
Wire.beginTransmission(this->i2cAddress); //begin transmitting
Wire.write(0x80); //command mode
Wire.write(com);
Wire.endTransmission(); // stop transmitting
#endif
}

void SSD1306::sendInitCommands(void) {
Expand Down
16 changes: 14 additions & 2 deletions SSD1306.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,10 +28,22 @@
#pragma once

#include <Arduino.h>
#include <Wire.h>

#include "SSD1306Fonts.h"

#ifdef SSD1306_USE_BRZO
#include "brzo_i2c.h"
// Brzo can handle 1Mhz in ESP8266 160Mhz mode
// and 800KHz in 80Mhz mode
#if F_CPU == 160000000L
#define BRZO_I2C_SPEED 1000
#else
#define BRZO_I2C_SPEED 800
#endif
#else // Default use Wire
#include <Wire.h>
#endif


//#define DEBUG_SSD1306(...) Serial.printf( __VA_ARGS__ )

#ifndef DEBUG_SSD1306
Expand Down

0 comments on commit 086e891

Please sign in to comment.