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Add OLED I2C display example
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kholia committed Mar 26, 2022
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/***********************************************************************|
| TinyWSoftware i2c master library for ATtiny13 |
| |
| i2c_oled.ino (by Dhiru Kholia - VU3CER) |
| |
| Based on https://github.com/wagiminator/ATtiny13-TinyOLEDdemo (by |
| Stefan Wagner - wagiminator) |
| |
| In this example we drive a 0.96" OLED Display Module over I2C. |
| |
| SERIAL REMINDER |
| The baud rate is ignored on the ATtiny13 due to using a simplified |
| serial. The baud rate used is dependent on the processor speed. |
| Note that you can specify a custom baud rate if the following ones |
| does not fit your application. |
| |
| THESE CLOCKS USES 115200 BAUD: THIS CLOCK USES 57600 BAUD: |
| 20 MHz, 16 MHz, 9.6 MHz, 8 MHz 4.8 MHz |
| THESE CLOCKS USES 19200 BAUD: THIS CLOCK USES 9600 BAUD: |
| 1.2 MHz, 1 MHz 600 KHz |
| |
| If you get garbage output: |
| 1. Check baud rate as above |
| 2. Check if you have anything else connected to TX/RX like an LED |
| 3. Check OSCCAL (see MicroCore OSCCAL tuner example) |
|***********************************************************************/

#include <TinyWire.h>

// We have to define which pins to use for SDA and SCL
const uint8_t TinyWire::SCL = 3;
const uint8_t TinyWire::SDA = 4;

// Sets the i2c clock speed in [Hz]
// Use MAX_SPEED for the highest possible clock speed
const uint32_t TinyWire::FREQ = 100000;

// OLED definitions
#define OLED_ADDR 0x3C // OLED write address - for '0.96" OLED Display Module'
#define OLED_CMD_MODE 0x00 // set command mode
#define OLED_DAT_MODE 0x40 // set data mode
#define OLED_INIT_LEN 14 // 12: no screen flip, 14: screen flip

// OLED init settings
const uint8_t OLED_INIT_CMD[] PROGMEM = {
0xA8, 0x1F, // set multiplex (HEIGHT-1): 0x1F for 128x32, 0x3F for 128x64
0x22, 0x00, 0x03, // set min and max page
0x20, 0x00, // set horizontal memory addressing mode
0xDA, 0x02, // set COM pins hardware configuration to sequential
0x8D, 0x14, // enable charge pump
0xAF, // switch on OLED
0xA1, 0xC8 // flip the screen
};

// standard ASCII 5x8 font (adapted from Neven Boyanov and Stephen Denne)
const uint8_t OLED_FONT[] PROGMEM = {
0x00, 0x00, 0x00, 0x00, 0x00, // 0
0x00, 0x00, 0x2f, 0x00, 0x00, // ! 1
0x00, 0x07, 0x00, 0x07, 0x00, // " 2
0x14, 0x7f, 0x14, 0x7f, 0x14, // # 3
0x24, 0x2a, 0x7f, 0x2a, 0x12, // $ 4
0x62, 0x64, 0x08, 0x13, 0x23, // % 5
0x36, 0x49, 0x55, 0x22, 0x50, // & 6
0x00, 0x05, 0x03, 0x00, 0x00, // ' 7
0x00, 0x1c, 0x22, 0x41, 0x00, // ( 8
0x00, 0x41, 0x22, 0x1c, 0x00, // ) 9
0x14, 0x08, 0x3E, 0x08, 0x14, // * 10
0x08, 0x08, 0x3E, 0x08, 0x08, // + 11
0x00, 0x00, 0xA0, 0x60, 0x00, // , 12
0x08, 0x08, 0x08, 0x08, 0x08, // - 13
0x00, 0x60, 0x60, 0x00, 0x00, // . 14
0x20, 0x10, 0x08, 0x04, 0x02, // / 15
0x3E, 0x51, 0x49, 0x45, 0x3E, // 0 16
0x00, 0x42, 0x7F, 0x40, 0x00, // 1 17
0x42, 0x61, 0x51, 0x49, 0x46, // 2 18
0x21, 0x41, 0x45, 0x4B, 0x31, // 3 19
0x18, 0x14, 0x12, 0x7F, 0x10, // 4 20
0x27, 0x45, 0x45, 0x45, 0x39, // 5 21
0x3C, 0x4A, 0x49, 0x49, 0x30, // 6 22
0x01, 0x71, 0x09, 0x05, 0x03, // 7 23
0x36, 0x49, 0x49, 0x49, 0x36, // 8 24
0x06, 0x49, 0x49, 0x29, 0x1E, // 9 25
0x00, 0x36, 0x36, 0x00, 0x00, // : 26
0x00, 0x56, 0x36, 0x00, 0x00, // ; 27
0x08, 0x14, 0x22, 0x41, 0x00, // < 28
0x14, 0x14, 0x14, 0x14, 0x14, // = 29
0x00, 0x41, 0x22, 0x14, 0x08, // > 30
0x02, 0x01, 0x51, 0x09, 0x06, // ? 31
0x32, 0x49, 0x59, 0x51, 0x3E, // @ 32
0x7C, 0x12, 0x11, 0x12, 0x7C, // A 33
0x7F, 0x49, 0x49, 0x49, 0x36, // B 34
0x3E, 0x41, 0x41, 0x41, 0x22, // C 35
0x7F, 0x41, 0x41, 0x22, 0x1C, // D 36
0x7F, 0x49, 0x49, 0x49, 0x41, // E 37
0x7F, 0x09, 0x09, 0x09, 0x01, // F 38
0x3E, 0x41, 0x49, 0x49, 0x7A, // G 39
0x7F, 0x08, 0x08, 0x08, 0x7F, // H 40
0x00, 0x41, 0x7F, 0x41, 0x00, // I 41
0x20, 0x40, 0x41, 0x3F, 0x01, // J 42
0x7F, 0x08, 0x14, 0x22, 0x41, // K 43
0x7F, 0x40, 0x40, 0x40, 0x40, // L 44
0x7F, 0x02, 0x0C, 0x02, 0x7F, // M 45
0x7F, 0x04, 0x08, 0x10, 0x7F, // N 46
0x3E, 0x41, 0x41, 0x41, 0x3E, // O 47
0x7F, 0x09, 0x09, 0x09, 0x06, // P 48
0x3E, 0x41, 0x51, 0x21, 0x5E, // Q 49
0x7F, 0x09, 0x19, 0x29, 0x46, // R 50
0x46, 0x49, 0x49, 0x49, 0x31, // S 51
0x01, 0x01, 0x7F, 0x01, 0x01, // T 52
0x3F, 0x40, 0x40, 0x40, 0x3F, // U 53
0x1F, 0x20, 0x40, 0x20, 0x1F, // V 54
0x3F, 0x40, 0x38, 0x40, 0x3F, // W 55
0x63, 0x14, 0x08, 0x14, 0x63, // X 56
0x07, 0x08, 0x70, 0x08, 0x07, // Y 57
0x61, 0x51, 0x49, 0x45, 0x43, // Z 58
0x00, 0x7F, 0x41, 0x41, 0x00, // [ 59
0x02, 0x04, 0x08, 0x10, 0x20, // \ 60
0x00, 0x41, 0x41, 0x7F, 0x00, // ] 61
0x04, 0x02, 0x01, 0x02, 0x04, // ^ 62
0x40, 0x40, 0x40, 0x40, 0x40 // _ 63
};

// messages to print on OLED
const char Message1[] PROGMEM = "HELLO WORLD! :)";

// OLED init function
void OLED_init(void) {
Wire.beginTransmission(OLED_ADDR);
Wire.write(OLED_CMD_MODE); // set command mode
for (uint8_t i = 0; i < OLED_INIT_LEN; i++)
Wire.write(pgm_read_byte(&OLED_INIT_CMD[i])); // send the command bytes
Wire.endTransmission(); // initialize I2C first
}

// OLED set vertical shift
void OLED_shift(uint8_t ypos) {
Wire.beginTransmission(OLED_ADDR); // start transmission to OLED
Wire.write(OLED_CMD_MODE); // set command mode
Wire.write(0xD3); // vertical shift command
Wire.write(ypos); // set vertical shift value
Wire.endTransmission(); // stop transmission
}

// OLED print a character
void OLED_printC(char ch) {
uint16_t offset = ch - 32; // calculate position of character in font array
offset += offset << 2; // -> offset = (ch - 32) * 5
Wire.write(0x00); // print spacing between characters
for (uint8_t i = 5; i; i--)
Wire.write(pgm_read_byte(&OLED_FONT[offset++])); // print character
}

// OLED print a string from program memory
void OLED_printP(const char* p) {
Wire.beginTransmission(OLED_ADDR); // start transmission to OLED
Wire.write(OLED_DAT_MODE); // set data mode
char ch = pgm_read_byte(p); // read first character from program memory
while (ch != 0) { // repeat until string terminator
OLED_printC(ch); // print character on OLED
ch = pgm_read_byte(++p); // read next character
}
Wire.endTransmission(); // stop transmission
}

// OLED set the cursor
void OLED_cursor(uint8_t xpos, uint8_t ypos) {
Wire.beginTransmission(OLED_ADDR); // start transmission to OLED
Wire.write(OLED_CMD_MODE); // set command mode
Wire.write(xpos & 0x0F); // set low nibble of start column
Wire.write(0x10 | (xpos >> 4)); // set high nibble of start column
Wire.write(0xB0 | (ypos & 0x07)); // set start page
Wire.endTransmission(); // stop transmission
}

// OLED clear screen
void OLED_clear(void) {
OLED_cursor(0, 0); // set cursor at upper left corner
Wire.beginTransmission(OLED_ADDR); // start transmission to OLED
Wire.write(OLED_DAT_MODE); // set data mode
for (uint16_t i = 512; i; i--)
Wire.write(0x00); // clear the screen
Wire.endTransmission(); // stop transmission
OLED_shift(0); // reset vertical shift
}

void setup()
{
// No baudrate to select. See header for details
Serial.begin();
Serial.println(F("Check your OLED screen ;)"));
OLED_init();
}

void loop()
{
while (1) {
OLED_clear(); // clear screen
OLED_cursor(0, 0); // set cursor position
OLED_printP(Message1); // print message 1
delay(5000);
}
}

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