Bradley Kohler / Mbed 2 deprecated Example_SSD1306

SSD1306 Example I2C communication without library

Dependencies:   mbed

thanks to this forum https://www.ccsinfo.com/forum/viewtopic.php?t=52836

main.cpp@0:cf50c95c11c5, 2017-11-22 (annotated)

Committer:
kohlerba
Date:
Wed Nov 22 21:33:27 2017 +0000
Revision:
0:cf50c95c11c5
SSD1306;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kohlerba 0:cf50c95c11c5 1 #include "mbed.h"
kohlerba 0:cf50c95c11c5 2
kohlerba 0:cf50c95c11c5 3 #define DISPLAY_RESET D0
kohlerba 0:cf50c95c11c5 4
kohlerba 0:cf50c95c11c5 5 #define SSD1306_LCDWIDTH 128
kohlerba 0:cf50c95c11c5 6 #define SSD1306_LCDHEIGHT 64
kohlerba 0:cf50c95c11c5 7 #define SSD1306_SETCONTRAST 0x81
kohlerba 0:cf50c95c11c5 8 #define SSD1306_DISPLAYALLON_RESUME 0xA4
kohlerba 0:cf50c95c11c5 9 #define SSD1306_DISPLAYALLON 0xA5
kohlerba 0:cf50c95c11c5 10 #define SSD1306_NORMALDISPLAY 0xA6
kohlerba 0:cf50c95c11c5 11 #define SSD1306_INVERTDISPLAY 0xA7
kohlerba 0:cf50c95c11c5 12 #define SSD1306_DISPLAYOFF 0xAE
kohlerba 0:cf50c95c11c5 13 #define SSD1306_DISPLAYON 0xAF
kohlerba 0:cf50c95c11c5 14 #define SSD1306_SETDISPLAYOFFSET 0xD3
kohlerba 0:cf50c95c11c5 15 #define SSD1306_SETCOMPINS 0xDA
kohlerba 0:cf50c95c11c5 16 #define SSD1306_SETVCOMDETECT 0xDB
kohlerba 0:cf50c95c11c5 17 #define SSD1306_SETDISPLAYCLOCKDIV 0xD5
kohlerba 0:cf50c95c11c5 18 #define SSD1306_SETPRECHARGE 0xD9
kohlerba 0:cf50c95c11c5 19 #define SSD1306_SETMULTIPLEX 0xA8
kohlerba 0:cf50c95c11c5 20 #define SSD1306_SETLOWCOLUMN 0x00
kohlerba 0:cf50c95c11c5 21 #define SSD1306_SETHIGHCOLUMN 0x10
kohlerba 0:cf50c95c11c5 22 #define SSD1306_SETSTARTLINE 0x40
kohlerba 0:cf50c95c11c5 23 #define SSD1306_MEMORYMODE 0x20
kohlerba 0:cf50c95c11c5 24 #define SSD1306_COLUMNADDR 0x21
kohlerba 0:cf50c95c11c5 25 #define SSD1306_PAGEADDR 0x22
kohlerba 0:cf50c95c11c5 26 #define SSD1306_COMSCANINC 0xC0
kohlerba 0:cf50c95c11c5 27 #define SSD1306_COMSCANDEC 0xC8
kohlerba 0:cf50c95c11c5 28 #define SSD1306_SEGREMAP 0xA0
kohlerba 0:cf50c95c11c5 29 #define SSD1306_CHARGEPUMP 0x8D
kohlerba 0:cf50c95c11c5 30 #define SSD1306_EXTERNALVCC 0x1
kohlerba 0:cf50c95c11c5 31 #define SSD1306_SWITCHCAPVCC 0x2
kohlerba 0:cf50c95c11c5 32
kohlerba 0:cf50c95c11c5 33 I2C i2c(I2C_SDA, I2C_SCL);
kohlerba 0:cf50c95c11c5 34
kohlerba 0:cf50c95c11c5 35 char _i2c_address;
kohlerba 0:cf50c95c11c5 36 char display_buffer[1024];
kohlerba 0:cf50c95c11c5 37
kohlerba 0:cf50c95c11c5 38 void ssd1306_command(char c){
kohlerba 0:cf50c95c11c5 39 char control = 0x00;
kohlerba 0:cf50c95c11c5 40 i2c.start();
kohlerba 0:cf50c95c11c5 41 i2c.write(_i2c_address);
kohlerba 0:cf50c95c11c5 42 i2c.write(control);
kohlerba 0:cf50c95c11c5 43 i2c.write(c);
kohlerba 0:cf50c95c11c5 44 i2c.stop();
kohlerba 0:cf50c95c11c5 45 }
kohlerba 0:cf50c95c11c5 46
kohlerba 0:cf50c95c11c5 47 void ssd1306_data(char c){
kohlerba 0:cf50c95c11c5 48 i2c.start();
kohlerba 0:cf50c95c11c5 49 i2c.write(_i2c_address);
kohlerba 0:cf50c95c11c5 50 i2c.write(0x40);
kohlerba 0:cf50c95c11c5 51 i2c.write(c);
kohlerba 0:cf50c95c11c5 52 i2c.stop();
kohlerba 0:cf50c95c11c5 53 }
kohlerba 0:cf50c95c11c5 54
kohlerba 0:cf50c95c11c5 55 void setColAddress()
kohlerba 0:cf50c95c11c5 56 {
kohlerba 0:cf50c95c11c5 57 ssd1306_command(SSD1306_COLUMNADDR); // 0x21 COMMAND
kohlerba 0:cf50c95c11c5 58 ssd1306_command(0); // Column start address
kohlerba 0:cf50c95c11c5 59 ssd1306_command(SSD1306_LCDWIDTH-1); // Column end address
kohlerba 0:cf50c95c11c5 60 }
kohlerba 0:cf50c95c11c5 61
kohlerba 0:cf50c95c11c5 62 void setPageAddress()
kohlerba 0:cf50c95c11c5 63 {
kohlerba 0:cf50c95c11c5 64 ssd1306_command(SSD1306_PAGEADDR); // 0x22 COMMAND
kohlerba 0:cf50c95c11c5 65 ssd1306_command(0); // Start Page address
kohlerba 0:cf50c95c11c5 66 ssd1306_command((SSD1306_LCDHEIGHT/8)-1);// End Page address
kohlerba 0:cf50c95c11c5 67 }
kohlerba 0:cf50c95c11c5 68
kohlerba 0:cf50c95c11c5 69 void TransferBuffer()
kohlerba 0:cf50c95c11c5 70 {
kohlerba 0:cf50c95c11c5 71 int j=0;
kohlerba 0:cf50c95c11c5 72
kohlerba 0:cf50c95c11c5 73 // set the Column and Page addresses to 0,0
kohlerba 0:cf50c95c11c5 74 setColAddress();
kohlerba 0:cf50c95c11c5 75 setPageAddress();
kohlerba 0:cf50c95c11c5 76
kohlerba 0:cf50c95c11c5 77 i2c.start();
kohlerba 0:cf50c95c11c5 78 i2c.write(_i2c_address);
kohlerba 0:cf50c95c11c5 79 i2c.write(0X40); // data not command
kohlerba 0:cf50c95c11c5 80 for(j=0;j<1024;j++)
kohlerba 0:cf50c95c11c5 81 {
kohlerba 0:cf50c95c11c5 82 i2c.write(display_buffer[j]);
kohlerba 0:cf50c95c11c5 83 }
kohlerba 0:cf50c95c11c5 84
kohlerba 0:cf50c95c11c5 85 i2c.stop();
kohlerba 0:cf50c95c11c5 86 }
kohlerba 0:cf50c95c11c5 87
kohlerba 0:cf50c95c11c5 88 void InitializeDisplay()
kohlerba 0:cf50c95c11c5 89 {
kohlerba 0:cf50c95c11c5 90 DigitalOut(DISPLAY_RESET,1);
kohlerba 0:cf50c95c11c5 91 // VDD (3.3V) goes high at start, lets just chill for a ms
kohlerba 0:cf50c95c11c5 92 wait_ms(1);
kohlerba 0:cf50c95c11c5 93 // bring reset low
kohlerba 0:cf50c95c11c5 94 DigitalOut(DISPLAY_RESET,0);
kohlerba 0:cf50c95c11c5 95 // wait 10ms
kohlerba 0:cf50c95c11c5 96 wait_ms(10);
kohlerba 0:cf50c95c11c5 97 // bring out of reset
kohlerba 0:cf50c95c11c5 98 DigitalOut(DISPLAY_RESET,1);
kohlerba 0:cf50c95c11c5 99 // turn on VCC (9V?)
kohlerba 0:cf50c95c11c5 100
kohlerba 0:cf50c95c11c5 101 // Init sequence for 128x64 OLED module
kohlerba 0:cf50c95c11c5 102 ssd1306_command(SSD1306_DISPLAYOFF); // 0xAE
kohlerba 0:cf50c95c11c5 103
kohlerba 0:cf50c95c11c5 104 ssd1306_command(SSD1306_SETDISPLAYCLOCKDIV); // 0xD5
kohlerba 0:cf50c95c11c5 105 ssd1306_command(0x80); // the suggested ratio 0x80
kohlerba 0:cf50c95c11c5 106
kohlerba 0:cf50c95c11c5 107 ssd1306_command(SSD1306_SETMULTIPLEX); // 0xA8
kohlerba 0:cf50c95c11c5 108 ssd1306_command(0x3F);
kohlerba 0:cf50c95c11c5 109
kohlerba 0:cf50c95c11c5 110 ssd1306_command(SSD1306_SETDISPLAYOFFSET); // 0xD3
kohlerba 0:cf50c95c11c5 111 ssd1306_command(0x0); // no offset
kohlerba 0:cf50c95c11c5 112
kohlerba 0:cf50c95c11c5 113 ssd1306_command(SSD1306_SETSTARTLINE);// | 0x0); // line #0
kohlerba 0:cf50c95c11c5 114
kohlerba 0:cf50c95c11c5 115 ssd1306_command(SSD1306_CHARGEPUMP); // 0x8D
kohlerba 0:cf50c95c11c5 116 ssd1306_command(0x14); // using internal VCC
kohlerba 0:cf50c95c11c5 117
kohlerba 0:cf50c95c11c5 118 ssd1306_command(SSD1306_MEMORYMODE); // 0x20
kohlerba 0:cf50c95c11c5 119 ssd1306_command(0x00); // 0x00 horizontal addressing
kohlerba 0:cf50c95c11c5 120
kohlerba 0:cf50c95c11c5 121 ssd1306_command(SSD1306_SEGREMAP | 0x1); // rotate screen 180
kohlerba 0:cf50c95c11c5 122
kohlerba 0:cf50c95c11c5 123 ssd1306_command(SSD1306_COMSCANDEC); // rotate screen 180
kohlerba 0:cf50c95c11c5 124
kohlerba 0:cf50c95c11c5 125 ssd1306_command(SSD1306_SETCOMPINS); // 0xDA
kohlerba 0:cf50c95c11c5 126 ssd1306_command(0x12);
kohlerba 0:cf50c95c11c5 127
kohlerba 0:cf50c95c11c5 128 ssd1306_command(SSD1306_SETCONTRAST); // 0x81
kohlerba 0:cf50c95c11c5 129 ssd1306_command(0xCF);
kohlerba 0:cf50c95c11c5 130
kohlerba 0:cf50c95c11c5 131 ssd1306_command(SSD1306_SETPRECHARGE); // 0xd9
kohlerba 0:cf50c95c11c5 132 ssd1306_command(0xF1);
kohlerba 0:cf50c95c11c5 133
kohlerba 0:cf50c95c11c5 134 ssd1306_command(SSD1306_SETVCOMDETECT); // 0xDB
kohlerba 0:cf50c95c11c5 135 ssd1306_command(0x40);
kohlerba 0:cf50c95c11c5 136
kohlerba 0:cf50c95c11c5 137 ssd1306_command(SSD1306_DISPLAYALLON_RESUME); // 0xA4
kohlerba 0:cf50c95c11c5 138
kohlerba 0:cf50c95c11c5 139 ssd1306_command(SSD1306_NORMALDISPLAY); // 0xA6
kohlerba 0:cf50c95c11c5 140
kohlerba 0:cf50c95c11c5 141 ssd1306_command(SSD1306_DISPLAYON); //switch on OLED
kohlerba 0:cf50c95c11c5 142 }
kohlerba 0:cf50c95c11c5 143
kohlerba 0:cf50c95c11c5 144 int main() {
kohlerba 0:cf50c95c11c5 145
kohlerba 0:cf50c95c11c5 146 // fill buffer with something for test
kohlerba 0:cf50c95c11c5 147 memset( display_buffer, 0X02, 1024); // tried other values
kohlerba 0:cf50c95c11c5 148
kohlerba 0:cf50c95c11c5 149 _i2c_address = 0x78;
kohlerba 0:cf50c95c11c5 150
kohlerba 0:cf50c95c11c5 151 InitializeDisplay();
kohlerba 0:cf50c95c11c5 152
kohlerba 0:cf50c95c11c5 153 TransferBuffer(); // try sending buffer
kohlerba 0:cf50c95c11c5 154
kohlerba 0:cf50c95c11c5 155 while(1)
kohlerba 0:cf50c95c11c5 156 {
kohlerba 0:cf50c95c11c5 157 wait_ms(1000); // keyboard code here
kohlerba 0:cf50c95c11c5 158 if(DigitalIn(LED1) == 0){DigitalOut(LED1,1);}
kohlerba 0:cf50c95c11c5 159 else{DigitalOut(LED1,0);}
kohlerba 0:cf50c95c11c5 160 }
kohlerba 0:cf50c95c11c5 161 }