Foreword:
There is no preface. For relevant knowledge, please refer to my other blog. This one is for practice. The general idea is still to write the i2c device address in the device tree, register the i2c driver in the driver code, write the “hard operation of entering the number and note section” in the probe, and then initialize it according to the OLED data manual, and then pass it according to the application layer The characters are displayed on the OLED. As for how to display some of the click algorithms involved, we refer to the OLED code written in stm32 before. In fact, they are almost the same, and it is easy to transplant into C language.
Linux driver i2c subsystem mpu6050_Soul of Ca’s blog-CSDN blog
Code:
First ~ write the device tree. At first I looked at the data sheet and found that the address was 0x78, but then I never succeeded. Then I looked at someone else’s SSD1306 and the address was 0x3c. I tried it and it succeeded. I was very confused. Again, just write the address.
Device tree:
&i2c_7{
status = "okay";
mpu6050@68{
compatible = "lch-mpu6050";
reg = h;
};
oled@3c{
compatible = "lch-oled";
reg = ?;
};
};
Looking at the header file, driver.c and application.c should share a data structure, so that data transmission and docking between the application layer and the driver layer are more convenient. In the font array inside, you can create a new .h specifically for driver .c, so that application .c will be smaller.
oled.h
#ifndef __OLED_H__
#define __OLED_H__
union oled_data{//The size of the union depends on the largest member. It is best to use only one member at a time, because it is the same memory space and may be overwritten.
struct{
unsigned char x; //The left and right positions are 128/8=16, and the middle is 7
unsigned char y; //up and down position 64/16=4，0/2/4/6
unsigned char mystr[16];//Save characters
unsigned char size; //Which font 16/8
}font8_16;
struct{
unsigned char x; //The left and right positions are 128/6=21, and the middle is 10
unsigned char y; //The upper and lower positions are 64/8=8, and the middle is 3
unsigned char mystr[21];//Save characters
unsigned char size; //Which font 16/8
}font6_8;
};
//This is simply to get a unique number as a sign.
#define IOC_SET_FONT8_16 _IOR('M', 0x34,union oled_data)
#define IOC_SET_FONT6_8 _IOR('M', 0x35,union oled_data)
const unsigned char F8X16[]=
{
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,// 0
0x00,0x00,0x00,0xF8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x33,0x30,0x00,0x00,0x00,//! 1
0x00,0x10,0x0C,0x06,0x10,0x0C,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//" 2
0x40,0xC0,0x78,0x40,0xC0,0x78,0x40,0x00,0x04,0x3F,0x04,0x04,0x3F,0x04,0x04,0x00,//# 3
0x00,0x70,0x88,0xFC,0x08,0x30,0x00,0x00,0x00,0x18,0x20,0xFF,0x21,0x1E,0x00,0x00,//$ 4
0xF0,0x08,0xF0,0x00,0xE0,0x18,0x00,0x00,0x00,0x21,0x1C,0x03,0x1E,0x21,0x1E,0x00,//% 5
0x00,0xF0,0x08,0x88,0x70,0x00,0x00,0x00,0x1E,0x21,0x23,0x24,0x19,0x27,0x21,0x10,// & amp; 6
0x10,0x16,0x0E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//' 7
0x00,0x00,0x00,0xE0,0x18,0x04,0x02,0x00,0x00,0x00,0x00,0x07,0x18,0x20,0x40,0x00,//( 8
0x00,0x02,0x04,0x18,0xE0,0x00,0x00,0x00,0x00,0x40,0x20,0x18,0x07,0x00,0x00,0x00,//) 9
0x40,0x40,0x80,0xF0,0x80,0x40,0x40,0x00,0x02,0x02,0x01,0x0F,0x01,0x02,0x02,0x00,//* 10
0x00,0x00,0x00,0xF0,0x00,0x00,0x00,0x00,0x01,0x01,0x01,0x1F,0x01,0x01,0x01,0x00,// + 11
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0xB0,0x70,0x00,0x00,0x00,0x00,0x00,//, 12
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x01,0x01,0x01,0x01,0x01,//- 13
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00,0x00,0x00,//. 14
0x00,0x00,0x00,0x00,0x80,0x60,0x18,0x04,0x00,0x60,0x18,0x06,0x01,0x00,0x00,0x00,/// 15
0x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,0x00,0x0F,0x10,0x20,0x20,0x10,0x0F,0x00,//0 16
0x00,0x10,0x10,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//1 17
0x00,0x70,0x08,0x08,0x08,0x88,0x70,0x00,0x00,0x30,0x28,0x24,0x22,0x21,0x30,0x00,//2 18
0x00,0x30,0x08,0x88,0x88,0x48,0x30,0x00,0x00,0x18,0x20,0x20,0x20,0x11,0x0E,0x00,//3 19
0x00,0x00,0xC0,0x20,0x10,0xF8,0x00,0x00,0x00,0x07,0x04,0x24,0x24,0x3F,0x24,0x00,//4 20
0x00,0xF8,0x08,0x88,0x88,0x08,0x08,0x00,0x00,0x19,0x21,0x20,0x20,0x11,0x0E,0x00,//5 21
0x00,0xE0,0x10,0x88,0x88,0x18,0x00,0x00,0x00,0x0F,0x11,0x20,0x20,0x11,0x0E,0x00,//6 22
0x00,0x38,0x08,0x08,0xC8,0x38,0x08,0x00,0x00,0x00,0x00,0x3F,0x00,0x00,0x00,0x00,//7 23
0x00,0x70,0x88,0x08,0x08,0x88,0x70,0x00,0x00,0x1C,0x22,0x21,0x21,0x22,0x1C,0x00,//8 24
0x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,0x00,0x00,0x31,0x22,0x22,0x11,0x0F,0x00,//9 25
0x00,0x00,0x00,0xC0,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00,//: 26
0x00,0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x60,0x00,0x00,0x00,0x00,//; 27
0x00,0x00,0x80,0x40,0x20,0x10,0x08,0x00,0x00,0x01,0x02,0x04,0x08,0x10,0x20,0x00,//< 28
0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x00,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x00,//= 29
0x00,0x08,0x10,0x20,0x40,0x80,0x00,0x00,0x00,0x20,0x10,0x08,0x04,0x02,0x01,0x00,//> 30
0x00,0x70,0x48,0x08,0x08,0x08,0xF0,0x00,0x00,0x00,0x00,0x30,0x36,0x01,0x00,0x00,//? 31
0xC0,0x30,0xC8,0x28,0xE8,0x10,0xE0,0x00,0x07,0x18,0x27,0x24,0x23,0x14,0x0B,0x00,//@ 32
0x00,0x00,0xC0,0x38,0xE0,0x00,0x00,0x00,0x20,0x3C,0x23,0x02,0x02,0x27,0x38,0x20,//A 33
0x08,0xF8,0x88,0x88,0x88,0x70,0x00,0x00,0x20,0x3F,0x20,0x20,0x20,0x11,0x0E,0x00,//B 34
0xC0,0x30,0x08,0x08,0x08,0x08,0x38,0x00,0x07,0x18,0x20,0x20,0x20,0x10,0x08,0x00,//C 35
0x08,0xF8,0x08,0x08,0x08,0x10,0xE0,0x00,0x20,0x3F,0x20,0x20,0x20,0x10,0x0F,0x00,//D 36
0x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,0x20,0x3F,0x20,0x20,0x23,0x20,0x18,0x00,//E 37
0x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,0x20,0x3F,0x20,0x00,0x03,0x00,0x00,0x00,//F 38
0xC0,0x30,0x08,0x08,0x08,0x38,0x00,0x00,0x07,0x18,0x20,0x20,0x22,0x1E,0x02,0x00,//G 39
0x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,0x20,0x3F,0x21,0x01,0x01,0x21,0x3F,0x20,//H 40
0x00,0x08,0x08,0xF8,0x08,0x08,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//I 41
0x00,0x00,0x08,0x08,0xF8,0x08,0x08,0x00,0xC0,0x80,0x80,0x80,0x7F,0x00,0x00,0x00,//J 42
0x08,0xF8,0x88,0xC0,0x28,0x18,0x08,0x00,0x20,0x3F,0x20,0x01,0x26,0x38,0x20,0x00,//K 43
0x08,0xF8,0x08,0x00,0x00,0x00,0x00,0x00,0x20,0x3F,0x20,0x20,0x20,0x20,0x30,0x00,//L 44
0x08,0xF8,0xF8,0x00,0xF8,0xF8,0x08,0x00,0x20,0x3F,0x00,0x3F,0x00,0x3F,0x20,0x00,//M 45
0x08,0xF8,0x30,0xC0,0x00,0x08,0xF8,0x08,0x20,0x3F,0x20,0x00,0x07,0x18,0x3F,0x00,//N 46
0xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,0x0F,0x10,0x20,0x20,0x20,0x10,0x0F,0x00,//O 47
0x08,0xF8,0x08,0x08,0x08,0x08,0xF0,0x00,0x20,0x3F,0x21,0x01,0x01,0x01,0x00,0x00,//P 48
0xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,0x0F,0x18,0x24,0x24,0x38,0x50,0x4F,0x00,//Q 49
0x08,0xF8,0x88,0x88,0x88,0x88,0x70,0x00,0x20,0x3F,0x20,0x00,0x03,0x0C,0x30,0x20,//R 50
0x00,0x70,0x88,0x08,0x08,0x08,0x38,0x00,0x00,0x38,0x20,0x21,0x21,0x22,0x1C,0x00,//S 51
0x18,0x08,0x08,0xF8,0x08,0x08,0x18,0x00,0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00,//T 52
0x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00,//U 53
0x08,0x78,0x88,0x00,0x00,0xC8,0x38,0x08,0x00,0x00,0x07,0x38,0x0E,0x01,0x00,0x00,//V 54
0xF8,0x08,0x00,0xF8,0x00,0x08,0xF8,0x00,0x03,0x3C,0x07,0x00,0x07,0x3C,0x03,0x00,//W 55
0x08,0x18,0x68,0x80,0x80,0x68,0x18,0x08,0x20,0x30,0x2C,0x03,0x03,0x2C,0x30,0x20,//X 56
0x08,0x38,0xC8,0x00,0xC8,0x38,0x08,0x00,0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00,//Y 57
0x10,0x08,0x08,0x08,0xC8,0x38,0x08,0x00,0x20,0x38,0x26,0x21,0x20,0x20,0x18,0x00,//Z 58
0x00,0x00,0x00,0xFE,0x02,0x02,0x02,0x00,0x00,0x00,0x00,0x7F,0x40,0x40,0x40,0x00,//[ 59
0x00,0x0C,0x30,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x06,0x38,0xC0,0x00,//\ 60
0x00,0x02,0x02,0x02,0xFE,0x00,0x00,0x00,0x00,0x40,0x40,0x40,0x7F,0x00,0x00,0x00,//] 61
0x00,0x00,0x04,0x02,0x02,0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//^ 62
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,//_ 63
0x00,0x02,0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//` 64
0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x19,0x24,0x22,0x22,0x22,0x3F,0x20,//a 65
0x08,0xF8,0x00,0x80,0x80,0x00,0x00,0x00,0x00,0x3F,0x11,0x20,0x20,0x11,0x0E,0x00,//b 66
0x00,0x00,0x00,0x80,0x80,0x80,0x00,0x00,0x00,0x0E,0x11,0x20,0x20,0x20,0x11,0x00,//c 67
0x00,0x00,0x00,0x80,0x80,0x88,0xF8,0x00,0x00,0x0E,0x11,0x20,0x20,0x10,0x3F,0x20,//d 68
0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x1F,0x22,0x22,0x22,0x22,0x13,0x00,//e 69
0x00,0x80,0x80,0xF0,0x88,0x88,0x88,0x18,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//f 70
0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x6B,0x94,0x94,0x94,0x93,0x60,0x00,//g 71
0x08,0xF8,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20,//h 72
0x00,0x80,0x98,0x98,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//i 73
0x00,0x00,0x00,0x80,0x98,0x98,0x00,0x00,0x00,0xC0,0x80,0x80,0x80,0x7F,0x00,0x00,//j 74
0x08,0xF8,0x00,0x00,0x80,0x80,0x80,0x00,0x20,0x3F,0x24,0x02,0x2D,0x30,0x20,0x00,//k 75
0x00,0x08,0x08,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//l 76
0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x00,0x20,0x3F,0x20,0x00,0x3F,0x20,0x00,0x3F,//m 77
0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20,//n 78
0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00,//o 79
0x80,0x80,0x00,0x80,0x80,0x00,0x00,0x00,0x80,0xFF,0xA1,0x20,0x20,0x11,0x0E,0x00,//p 80
0x00,0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x0E,0x11,0x20,0x20,0xA0,0xFF,0x80,//q 81
0x80,0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x20,0x20,0x3F,0x21,0x20,0x00,0x01,0x00,//r 82
0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x33,0x24,0x24,0x24,0x24,0x19,0x00,//s 83
0x00,0x80,0x80,0xE0,0x80,0x80,0x00,0x00,0x00,0x00,0x00,0x1F,0x20,0x20,0x00,0x00,//t 84
0x80,0x80,0x00,0x00,0x00,0x80,0x80,0x00,0x00,0x1F,0x20,0x20,0x20,0x10,0x3F,0x20,//u 85
0x80,0x80,0x80,0x00,0x00,0x80,0x80,0x80,0x00,0x01,0x0E,0x30,0x08,0x06,0x01,0x00,//v 86
0x80,0x80,0x00,0x80,0x00,0x80,0x80,0x80,0x0F,0x30,0x0C,0x03,0x0C,0x30,0x0F,0x00,//w 87
0x00,0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x31,0x2E,0x0E,0x31,0x20,0x00,//x 88
0x80,0x80,0x80,0x00,0x00,0x80,0x80,0x80,0x80,0x81,0x8E,0x70,0x18,0x06,0x01,0x00,//y 89
0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x21,0x30,0x2C,0x22,0x21,0x30,0x00,//z 90
0x00,0x00,0x00,0x00,0x80,0x7C,0x02,0x02,0x00,0x00,0x00,0x00,0x00,0x3F,0x40,0x40,//{ 91
0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,//| 92
0x00,0x02,0x02,0x7C,0x80,0x00,0x00,0x00,0x00,0x40,0x40,0x3F,0x00,0x00,0x00,0x00,//} 93
0x00,0x06,0x01,0x01,0x02,0x02,0x04,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//~ 94
};
//Commonly used ASCII tables
//Offset 32
//ASCII character set
//Offset 32
//Size:12*6
/**********************************6*8 dot matrix****** *******************************/
const unsigned char F6x8[][6] =
{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00,// sp
0x00, 0x00, 0x00, 0x2f, 0x00, 0x00,// !
0x00, 0x00, 0x07, 0x00, 0x07, 0x00,// "
0x00, 0x14, 0x7f, 0x14, 0x7f, 0x14,// #
0x00, 0x24, 0x2a, 0x7f, 0x2a, 0x12,// $
0x00, 0x62, 0x64, 0x08, 0x13, 0x23,// %
0x00, 0x36, 0x49, 0x55, 0x22, 0x50,// & amp;
0x00, 0x00, 0x05, 0x03, 0x00, 0x00,// '
0x00, 0x00, 0x1c, 0x22, 0x41, 0x00,// (
0x00, 0x00, 0x41, 0x22, 0x1c, 0x00,// )
0x00, 0x14, 0x08, 0x3E, 0x08, 0x14,// *
0x00, 0x08, 0x08, 0x3E, 0x08, 0x08,// +
0x00, 0x00, 0x00, 0xA0, 0x60, 0x00,// ,
0x00, 0x08, 0x08, 0x08, 0x08, 0x08,// -
0x00, 0x00, 0x60, 0x60, 0x00, 0x00,// .
0x00, 0x20, 0x10, 0x08, 0x04, 0x02,// /
0x00, 0x3E, 0x51, 0x49, 0x45, 0x3E,// 0
0x00, 0x00, 0x42, 0x7F, 0x40, 0x00,// 1
0x00, 0x42, 0x61, 0x51, 0x49, 0x46,// 2
0x00, 0x21, 0x41, 0x45, 0x4B, 0x31,// 3
0x00, 0x18, 0x14, 0x12, 0x7F, 0x10,// 4
0x00, 0x27, 0x45, 0x45, 0x45, 0x39,// 5
0x00, 0x3C, 0x4A, 0x49, 0x49, 0x30,// 6
0x00, 0x01, 0x71, 0x09, 0x05, 0x03,// 7
0x00, 0x36, 0x49, 0x49, 0x49, 0x36,// 8
0x00, 0x06, 0x49, 0x49, 0x29, 0x1E,// 9
0x00, 0x00, 0x36, 0x36, 0x00, 0x00,//:
0x00, 0x00, 0x56, 0x36, 0x00, 0x00,//;
0x00, 0x08, 0x14, 0x22, 0x41, 0x00,// <
0x00, 0x14, 0x14, 0x14, 0x14, 0x14,// =
0x00, 0x00, 0x41, 0x22, 0x14, 0x08,// >
0x00, 0x02, 0x01, 0x51, 0x09, 0x06,// ?
0x00, 0x32, 0x49, 0x59, 0x51, 0x3E,// @
0x00, 0x7C, 0x12, 0x11, 0x12, 0x7C,// A
0x00, 0x7F, 0x49, 0x49, 0x49, 0x36,// B
0x00, 0x3E, 0x41, 0x41, 0x41, 0x22,// C
0x00, 0x7F, 0x41, 0x41, 0x22, 0x1C,// D
0x00, 0x7F, 0x49, 0x49, 0x49, 0x41,// E
0x00, 0x7F, 0x09, 0x09, 0x09, 0x01,// F
0x00, 0x3E, 0x41, 0x49, 0x49, 0x7A,// G
0x00, 0x7F, 0x08, 0x08, 0x08, 0x7F,// H
0x00, 0x00, 0x41, 0x7F, 0x41, 0x00,//I
0x00, 0x20, 0x40, 0x41, 0x3F, 0x01,// J
0x00, 0x7F, 0x08, 0x14, 0x22, 0x41,// K
0x00, 0x7F, 0x40, 0x40, 0x40, 0x40,// L
0x00, 0x7F, 0x02, 0x0C, 0x02, 0x7F,// M
0x00, 0x7F, 0x04, 0x08, 0x10, 0x7F,// N
0x00, 0x3E, 0x41, 0x41, 0x41, 0x3E,// O
0x00, 0x7F, 0x09, 0x09, 0x09, 0x06,// P
0x00, 0x3E, 0x41, 0x51, 0x21, 0x5E,// Q
0x00, 0x7F, 0x09, 0x19, 0x29, 0x46,// R
0x00, 0x46, 0x49, 0x49, 0x49, 0x31,// S
0x00, 0x01, 0x01, 0x7F, 0x01, 0x01,// T
0x00, 0x3F, 0x40, 0x40, 0x40, 0x3F,// U
0x00, 0x1F, 0x20, 0x40, 0x20, 0x1F,// V
0x00, 0x3F, 0x40, 0x38, 0x40, 0x3F,// W
0x00, 0x63, 0x14, 0x08, 0x14, 0x63,// X
0x00, 0x07, 0x08, 0x70, 0x08, 0x07,// Y
0x00, 0x61, 0x51, 0x49, 0x45, 0x43,// Z
0x00, 0x00, 0x7F, 0x41, 0x41, 0x00,// [
0x00, 0x55, 0x2A, 0x55, 0x2A, 0x55,// 55
0x00, 0x00, 0x41, 0x41, 0x7F, 0x00,// ]
0x00, 0x04, 0x02, 0x01, 0x02, 0x04,// ^
0x00, 0x40, 0x40, 0x40, 0x40, 0x40,// _
0x00, 0x00, 0x01, 0x02, 0x04, 0x00,// '
0x00, 0x20, 0x54, 0x54, 0x54, 0x78,// a
0x00, 0x7F, 0x48, 0x44, 0x44, 0x38,// b
0x00, 0x38, 0x44, 0x44, 0x44, 0x20,// c
0x00, 0x38, 0x44, 0x44, 0x48, 0x7F,// d
0x00, 0x38, 0x54, 0x54, 0x54, 0x18,//e
0x00, 0x08, 0x7E, 0x09, 0x01, 0x02,// f
0x00, 0x18, 0xA4, 0xA4, 0xA4, 0x7C,// g
0x00, 0x7F, 0x08, 0x04, 0x04, 0x78,//h
0x00, 0x00, 0x44, 0x7D, 0x40, 0x00,// i
0x00, 0x40, 0x80, 0x84, 0x7D, 0x00,// j
0x00, 0x7F, 0x10, 0x28, 0x44, 0x00,// k
0x00, 0x00, 0x41, 0x7F, 0x40, 0x00,//l
0x00, 0x7C, 0x04, 0x18, 0x04, 0x78,// m
0x00, 0x7C, 0x08, 0x04, 0x04, 0x78,// n
0x00, 0x38, 0x44, 0x44, 0x44, 0x38,// o
0x00, 0xFC, 0x24, 0x24, 0x24, 0x18,// p
0x00, 0x18, 0x24, 0x24, 0x18, 0xFC,// q
0x00, 0x7C, 0x08, 0x04, 0x04, 0x08,// r
0x00, 0x48, 0x54, 0x54, 0x54, 0x20,// s
0x00, 0x04, 0x3F, 0x44, 0x40, 0x20,// t
0x00, 0x3C, 0x40, 0x40, 0x20, 0x7C,// u
0x00, 0x1C, 0x20, 0x40, 0x20, 0x1C,// v
0x00, 0x3C, 0x40, 0x30, 0x40, 0x3C,// w
0x00, 0x44, 0x28, 0x10, 0x28, 0x44,// x
0x00, 0x1C, 0xA0, 0xA0, 0xA0, 0x7C,// y
0x00, 0x44, 0x64, 0x54, 0x4C, 0x44,// z
0x14, 0x14, 0x14, 0x14, 0x14, 0x14,// horiz lines
};
#endif
16th_i2c_0.96oled.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h>
#include <linux/i2c.h>
#include <linux/types.h>
#include <asm/io.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
\t\t\t\t\t\t\t\t\t
#include "oled.h"
\t\t\t\t\t\t\t\t\t
#define OLED_CMD 0 //Write command
#define OLED_DATA 1 //Write data
#define OLED_MODE 0
#define COMMAND 0X00 //The data in the register set is updated according to the sampling frequency
#defineMYDATA 0X40
//OLED mode setting
//0:4-wire serial mode
//1: Parallel 8080 mode not used
#define SIZE 16
#define XLevelL 0x02
#define XLevelH 0x10
#define Max_Column 128
#define Max_Row 64
#define Brightness 0xFF
#define X_WIDTH 128
#define Y_WIDTH 64
//Design a global device object
//Mainly record the client as global, some functions need to be used
struct oled_sensor{
int dev_major;
struct device *dev;
struct class *cls;
struct i2c_client *client;//Record client in probe
};
struct oled_sensor *oled_dev;
//The underlying code for assigning values to the oled register
int oled_write_bytes(struct i2c_client *client, char *buf, int count)
{
int ret;
struct i2c_adapter *adapter = client->adapter;
struct i2c_msg msg;
msg.addr = client->addr;
msg.flags = 0;
msg.len = count;
msg.buf = buf;
\t
ret = i2c_transfer(adapter, &msg, 1);
return ret==1?count:ret;
}
//Not used in this code
int oled_read_bytes(struct i2c_client *client, char *buf, int count)
{
\t
int ret;
struct i2c_adapter *adapter = client->adapter;
struct i2c_msg msg;
\t
msg.addr = client->addr;
msg.flags = I2C_M_RD;
msg.len = count;
msg.buf = buf;
\t\t
ret = i2c_transfer(adapter, & amp;msg, 1);//0 write 1 read
\t
return ret==1?count:ret;
}
//Read the address of a specific register and return the value
//This code is not used
int oled_read_reg_byte(struct i2c_client *client, char reg)
{
//Write the address of the register first, then read the value of the register
int ret;
struct i2c_adapter *adapter = client->adapter;
struct i2c_msg msg[2];
char rxbuf[1];
\t
msg[0].addr = client->addr;
msg[0].flags = 0;
msg[0].len = 1;
msg[0].buf = & amp;reg;
msg[1].addr = client->addr;
msg[1].flags = I2C_M_RD;
msg[1].len = 1;
msg[1].buf = rxbuf;
\t\t
ret = i2c_transfer(adapter, msg, 2);
if(ret < 0)
{
printk("i2c_transfer read error\
");
return ret;
}
return rxbuf[0];
}
//In oled, register 0x40 is the data register
//Register 0x00 is the command register
void OLED_WR_Byte(unsigned char dat,unsigned char cmd){
if(cmd==1){//Write data 0x40 + dat
char buf1[2] = {MYDATA, dat};
oled_write_bytes(oled_dev->client, buf1, 2);
\t\t
}else{//Write command 0x00 + dat
char buf2[2] = {COMMAND, dat};
oled_write_bytes(oled_dev->client, buf2, 2);
}
}
//Clear screen function, after clearing the screen, the entire screen will be black! It’s the same as not being lit!!!
void OLED_Clear(void)
{
u8i,n;
for(i=0;i<8;i + + )
{
OLED_WR_Byte (0xb0 + i,OLED_CMD); //Set page address (0~7)
OLED_WR_Byte (0x00,OLED_CMD); //Set the display position-column low address
OLED_WR_Byte (0x10,OLED_CMD); //Set the display position-column high address
for(n=0;n<128;n + + )OLED_WR_Byte(0,OLED_DATA);
} //Update display
}
//Copied from stm32
void OLED_Init(void)
{
mdelay(100);//Delay for more stability
OLED_WR_Byte(0xAE,OLED_CMD);//--display on
OLED_WR_Byte(0x00,OLED_CMD);//---set low column address
OLED_WR_Byte(0x10,OLED_CMD);//---set high column address
OLED_WR_Byte(0x40,OLED_CMD);//--set start line address
OLED_WR_Byte(0xB0,OLED_CMD);//--set page address
OLED_WR_Byte(0x81,OLED_CMD); // contract control
OLED_WR_Byte(0xFF,OLED_CMD);//--128
OLED_WR_Byte(0xA1,OLED_CMD);//set segment remap
OLED_WR_Byte(0xA6,OLED_CMD);//--normal / reverses
OLED_WR_Byte(0xA8,OLED_CMD);//--set multiplex ratio(1 to 64)
OLED_WR_Byte(0x3F,OLED_CMD);//--1/32 duty
OLED_WR_Byte(0xC8,OLED_CMD);//Com scan direction
OLED_WR_Byte(0xD3,OLED_CMD);//-set display offset
OLED_WR_Byte(0x00,OLED_CMD);//
OLED_WR_Byte(0xD5,OLED_CMD);//set osc division
OLED_WR_Byte(0x80,OLED_CMD);//
OLED_WR_Byte(0xD8,OLED_CMD);//set area color mode off
OLED_WR_Byte(0x05,OLED_CMD);//
OLED_WR_Byte(0xD9,OLED_CMD);//Set Pre-Charge Period
OLED_WR_Byte(0xF1,OLED_CMD);//
OLED_WR_Byte(0xDA,OLED_CMD);//set com pin configuration
OLED_WR_Byte(0x12,OLED_CMD);//
OLED_WR_Byte(0xDB,OLED_CMD);//set Vcomh
OLED_WR_Byte(0x30,OLED_CMD);//
OLED_WR_Byte(0x8D,OLED_CMD);//set charge pump enable
OLED_WR_Byte(0x14,OLED_CMD);//
OLED_WR_Byte(0xAF,OLED_CMD);//--turn on oled panel
\t
}
//Copied from stm32
void OLED_Set_Pos(unsigned char x, unsigned char y)
{ OLED_WR_Byte(0xb0 + y,OLED_CMD);
OLED_WR_Byte(((x & amp;0xf0)>>4)|0x10,OLED_CMD);
OLED_WR_Byte((x & amp;0x0f),OLED_CMD);
}
//Display a character at the specified position, including some characters
//x:0~127
//y:0~63
//mode: 0, reverse display; 1, normal display
//size:Select font 16/12
void OLED_ShowChar(u8 x,u8 y,u8 chr,u8 Char_Size)
{
unsigned char c=0,i=0;
c=chr-' ';//Get the offset value
if(x>Max_Column-1){x=0;y=y + 2;}
if(Char_Size ==16)
{
OLED_Set_Pos(x,y);
for(i=0;i<8;i + + )
OLED_WR_Byte(F8X16[c*16 + i],OLED_DATA);
OLED_Set_Pos(x,y + 1);
for(i=0;i<8;i + + )
OLED_WR_Byte(F8X16[c*16 + i + 8],OLED_DATA);
}
else
{
OLED_Set_Pos(x,y);
for(i=0;i<6;i + + )
OLED_WR_Byte(F6x8[c][i],OLED_DATA);
}
}
//Copied, all copied
//Display a character string
void OLED_ShowString(u8 x,u8 y,u8 *chr,u8 Char_Size)
{
unsigned char j=0;
while (chr[j]!='\0')
{ OLED_ShowChar(x,y,chr[j],Char_Size);
x + =8;
if(x>120){x=0;y + =2;}
j + + ;
}
}
//When the application is running, initialize oled
int oled_drv_open(struct inode *inode, struct file *filp)
{
OLED_Init();
mdelay(200);
OLED_Clear();
mdelay(200);
OLED_Clear();
// OLED_ShowString(0,0,"lch",16); //Left and right, top and bottom, content, font size
// OLED_ShowString(0,2,"love",16);//8*16 128*64
//OLED_ShowString(0,4,"lyt",16);//There are 0, 2, 4, and 6 on y, and 16 on x
// OLED_ShowString(0,6,"lch",16); //The middle of x is 7, and the middle of y is 2
/*
6*8
x 128/6 = 21 x The middle is 10
y 128/8 = 16 y, the middle of y is 7
*/
return 0;
}
int oled_drv_close(struct inode *inode, struct file *filp)
{
return 0;
}
//Judge cmd to see if it is a font in 6*8 format or a font in 16*8 format
//Call the oled function again to display the string passed from the application layer (via & args)
long oled_drv_ioctl (struct file *filp, unsigned int cmd, unsigned long args)
{
union oled_data data;
\t
//Give all data to the user
if(copy_from_user( & amp;data,(void __user * )args, sizeof(data)) > 0)
return -EFAULT;
switch(cmd){
case IOC_SET_FONT8_16:
OLED_ShowString(data.font8_16.x,data.font8_16.y,data.font8_16.mystr,16);//left and right, top and bottom, content, font size
mdelay(100);
// OLED_Clear();
break;
case IOC_SET_FONT6_8:
OLED_ShowString(data.font6_8.x,data.font6_8.y,data.font6_8.mystr,8);//Left and right, top and bottom, content, font size
mdelay(100);
// OLED_Clear();
break;
default:
printk("invalid cmd\
");
return -EINVAL;
}
return 0;
}
const struct file_operations oled_fops = {
.open = oled_drv_open,
.release = oled_drv_close,
.unlocked_ioctl = oled_drv_ioctl,
};
//Character device related operations
int oled_drv_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
printk("-----%s----\
", __FUNCTION__);
/*
Apply for a device number and implement fops
Create device file
Initialize the i2c slave device through the i2c interface
*/
oled_dev = kzalloc(sizeof(struct oled_sensor), GFP_KERNEL);
\t
oled_dev->client = client;
oled_dev->dev_major = register_chrdev(0,"oled_drv", & amp;oled_fops);
oled_dev->cls = class_create(THIS_MODULE, "oled_cls");
oled_dev->dev = device_create(oled_dev->cls, NULL, MKDEV(oled_dev->dev_major, 0),
NULL, "my-oled");
\t
return 0;
}
int oled_drv_remove(struct i2c_client *client)
{
printk("-----%s----\
", __FUNCTION__);
device_destroy(oled_dev->cls, MKDEV(oled_dev->dev_major, 0));
class_destroy(oled_dev->cls);
unregister_chrdev(oled_dev->dev_major, "oled_drv");
kfree(oled_dev);
return 0;
}
//Things that match the device tree node
const struct of_device_id of_oled_id[] = {
{
.compatible = "lch-oled",
},
{/*northing to be done*/},
};
const struct i2c_device_id oled_id_table[] = {
{"oled_drv", 0x1111},
{/*northing to be done*/},
};
\t
struct i2c_driver oled_drv = {
.probe = oled_drv_probe,
.remove = oled_drv_remove,
.driver = {
.name = "lch-oled",//Write whatever you want, /sys/bus/i2c/driver/oled_drv
.of_match_table = of_match_ptr(of_oled_id),
},
\t
.id_table = oled_id_table, // Matching in non-device tree situations, no need to use it in device tree mode
};
//Register i2c driver to i2c_bus
static int __init oled_drv_init(void)
{
// 1. Build the i2c driver and register it to the i2c bus
return i2c_add_driver( & amp;oled_drv);
}
static void __exit oled_drv_exit(void)
{
i2c_del_driver( & amp;oled_drv);
}
module_init(oled_drv_init);
module_exit(oled_drv_exit);
MODULE_LICENSE("GPL");
app_i2c_0.96oled.c
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include "oled.h"
int fd;
void OLED_ShowString(unsigned char x, unsigned char y, unsigned char *chr, unsigned char Char_Size){
union oled_data data;
if(Char_Size==16){
data.font8_16.x = x;
data.font8_16.y = y;
strncpy(data.font8_16.mystr,chr,16);
data.font8_16.size = Char_Size;
ioctl(fd, IOC_SET_FONT8_16, & amp;data);
}else if(Char_Size==8){
data.font8_16.x = x;
data.font8_16.y = y;
strncpy(data.font8_16.mystr,chr,21);
data.font8_16.size = Char_Size;
ioctl(fd, IOC_SET_FONT6_8, & amp;data);
}
}
int main(int argc, char *argv[])
{
unsigned char i;
unsigned char mystr[20];
union oled_data data;
\t
fd = open("/dev/my-oled", O_RDWR);
if(fd < 0)
{
perror("open");
exit(1);
}
\t
while(1)
{
sprintf(mystr,"LOVE-%d",i + + );
OLED_ShowString(0,0,mystr,16);
usleep(20);
OLED_ShowString(0,2,mystr,16);
usleep(20);
OLED_ShowString(0,4,mystr,16);
usleep(20);
OLED_ShowString(0,6,mystr,16);
if(i>=200){
i=0;
}
sleep(1);
}
close(fd);
return 0;
}
Operating effect:
