参考文章:
1. u8g2移植教程:
STM32移植U8g2图形库——玩转OLED显示_u8g2库的使用_码农爱学习的博客-优快云博客
2. us级延迟实现:
STM32CubeIDE如何实现HAL库 微秒Us延迟(HAL_Us_Delay)_hal delay us-优快云博客
本次的实验硬件为:
- STM32:型号为最常见的STM32L431RCT6
- OLED:128x64,GPIO仿的IIC接口(如果是SPI接口,文中也有对应的修改介绍)
0 工程配置cubemx
- GPIO:仿I2C用,本实验中PB6仿SCL,PB7仿SDA
- TIM: 定时器,生成us级别的延时用
GPIO的配置无特殊处理,默认参数即可
tim6的配置参考文章2,注意修改两处参数,查阅数据手册,发现TIM6在APB1总线上,而APB1时钟为32HZ,所以修改两处参数为32-1=31和1。
其余部分常规设置,详情参考文章末尾视频。
1 U8g2简介
U8g2 是一个用于嵌入式设备的单色图形库。U8g2支持单色OLED和LCD,并支持如SSD1306等多种类型的OLED驱动。
U8g2源码的开源库地址:GitHub - olikraus/u8g2: U8glib library for monochrome displays, version 2
2 移植步骤
首先下载U8g2的源码,因为STM32主要是使用C语言编程,所以只需关注源码中的C源码部分,即csrc文件夹下的文件。
2.1 精简c源码
U8g2支持多种显示驱动的屏幕,因为源码中也包含了各个驱动对应的文件,为了减小整个工程的代码体积,在移植U8g2时,可以删除一些无用的文件。
2.1.1 去掉无用的驱动文件
这些驱动文件通常是u8x8_d_xxx.c,xxx包括驱动的型号和屏幕分辨率。ssd1306驱动芯片的OLED,使用u8x8_ssd1306_128x64_noname.c这个文件,其它的屏幕驱动和分辨率的文件可以删掉。
2.1.2 精简u8g2_d_setup.c
由于我的OLED是IIC接口,只留一个本次要用到的u8g2_Setup_ssd1306_i2c_128x64_noname_f就好(如果是SPI接口,需要使用u8g2_Setup_ssd1306_128x64_noname_f这个函数),其它的可以删掉或注释掉。
#include "u8g2.h"
/* ssd1306 f */
void u8g2_Setup_ssd1306_i2c_128x64_noname_f(u8g2_t *u8g2, const u8g2_cb_t *rotation, u8x8_msg_cb byte_cb, u8x8_msg_cb gpio_and_delay_cb)
{
uint8_t tile_buf_height;
uint8_t *buf;
u8g2_SetupDisplay(u8g2, u8x8_d_ssd1306_128x64_noname, u8x8_cad_ssd13xx_fast_i2c, byte_cb, gpio_and_delay_cb);
buf = u8g2_m_16_8_f(&tile_buf_height);
u8g2_SetupBuffer(u8g2, buf, tile_buf_height, u8g2_ll_hvline_vertical_top_lsb, rotation);
}
注意,与这个函数看起来十分相似的函数的有:
u8g2_Setup_ssd1306_128x64_noname_1
u8g2_Setup_ssd1306_128x64_noname_2
u8g2_Setup_ssd1306_128x64_noname_f
u8g2_Setup_ssd1306_i2c_128x64_noname_1
u8g2_Setup_ssd1306_i2c_128x64_noname_2
u8g2_Setup_ssd1306_i2c_128x64_noname_f
其中,前面3个,是给SPI接口的OLED用的,函数最后的数字或字母,代表显示时的buf大小:
1:128字节
2:256字节
f:1024字节
2.1.3 精简u8g2_d_memory.c
由于用到的u8g2_Setup_ssd1306_i2c_128x64_noname_f函数中,只调用了u8g2_m_16_8_f这个函数,所以留下这个函数,其它的函数一定要删掉或注释掉,否则编译时很可能会提示内存不足!!!
#include "u8g2.h"
uint8_t *u8g2_m_16_8_f(uint8_t *page_cnt)
{
#ifdef U8G2_USE_DYNAMIC_ALLOC
*page_cnt = 8;
return 0;
#else
static uint8_t buf[1024];
*page_cnt = 8;
return buf;
#endif
}
2.2 编写移植函数
精简源码之后,还需要编写如下的配置函数。
2.2.1 GPIO初始化
对OLED用到的IIC接口进行GPIO的初始化配置:
#define SCL_Pin GPIO_Pin_6
#define SDA_Pin GPIO_Pin_7
#define IIC_GPIO_Port GPIOB
注意,该初始化部分由cubemx自动生成,我们只需要在main.h文件中,添加几个define。
2.2.2 u8x8_gpio_and_delay
这个函数也需要自己写,主要的修改包括:
赋予U8g2相应的延时函数,比如下面的HAL_Delay_us
为U8g2提供IIC接口的高低电平调用:
U8X8_MSG_GPIO_I2C_CLOCK:IIC的SCL
U8X8_MSG_GPIO_I2C_DATA:IIC的SDA
uint8_t u8x8_gpio_and_delay(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
{
switch (msg)
{
case U8X8_MSG_DELAY_100NANO: // delay arg_int * 100 nano seconds
__NOP();
break;
case U8X8_MSG_DELAY_10MICRO: // delay arg_int * 10 micro seconds
for (uint16_t n = 0; n < 320; n++)
{
__NOP();
}
break;
case U8X8_MSG_DELAY_MILLI: // delay arg_int * 1 milli second
HAL_Delay(1);
break;
case U8X8_MSG_DELAY_I2C: // arg_int is the I2C speed in 100KHz, e.g. 4 = 400 KHz
HAL_Delay_us(5);
break; // arg_int=1: delay by 5us, arg_int = 4: delay by 1.25us
case U8X8_MSG_GPIO_I2C_CLOCK: // arg_int=0: Output low at I2C clock pin
if(arg_int == 1)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_6,GPIO_PIN_SET);
}
else if(arg_int == 0)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_6,GPIO_PIN_RESET);
}
break; // arg_int=1: Input dir with pullup high for I2C clock pin
case U8X8_MSG_GPIO_I2C_DATA: // arg_int=0: Output low at I2C data pin
if(arg_int == 1)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_7,GPIO_PIN_SET);
}
else if(arg_int == 0)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_7,GPIO_PIN_RESET);
}
break; // arg_int=1: Input dir with pullup high for I2C data pin
case U8X8_MSG_GPIO_MENU_SELECT:
u8x8_SetGPIOResult(u8x8, /* get menu select pin state */ 0);
break;
case U8X8_MSG_GPIO_MENU_NEXT:
u8x8_SetGPIOResult(u8x8, /* get menu next pin state */ 0);
break;
case U8X8_MSG_GPIO_MENU_PREV:
u8x8_SetGPIOResult(u8x8, /* get menu prev pin state */ 0);
break;
case U8X8_MSG_GPIO_MENU_HOME:
u8x8_SetGPIOResult(u8x8, /* get menu home pin state */ 0);
break;
default:
u8x8_SetGPIOResult(u8x8, 1); // default return value
break;
}
return 1;
}
注意:其中的HAL_Delay_us非HAL库自带函数,需要采用定时器自己编写该函数,在tim.c文件中,加入如下代码:
void HAL_Delay_us(uint16_t us)
{
uint16_t delay = 0xffff-us-5; //???????,????65535????1us
HAL_TIM_Base_Start(&htim6); //?????
__HAL_TIM_SetCounter(&htim6,delay); //?????
while(delay<0xffff-5)
{
delay = __HAL_TIM_GetCounter(&htim6);
}
HAL_TIM_Base_Stop(&htim6);
}
并在tim.h中声明。
2.2.3 u8g2Init
U8g2的初始化,需要调用下面这个u8g2_Setup_ssd1306_128x64_noname_f函数,该函数的4个参数含义:
u8g2:传入的U8g2结构体
U8G2_R0:默认使用U8G2_R0即可(用于配置屏幕是否要旋转)
u8x8_byte_sw_i2c:使用软件IIC驱动,该函数由U8g2源码提供
u8x8_gpio_and_delay:就是上面我们写的配置函数
在main.c中加入以下代码:
u8g2_Setup_ssd1306_i2c_128x64_noname_f(u8g2, U8G2_R0, u8x8_byte_sw_i2c, u8x8_gpio_and_delay); // 初始化 u8g2 结构体
u8g2_InitDisplay(u8g2); // 根据所选的芯片进行初始化工作,初始化完成后,显示器处于关闭状态
u8g2_SetPowerSave(u8g2, 0); // 打开显示器
u8g2_ClearBuffer(u8g2);
完成对oled的初始化。
2.2.4 显示测试函数
使用U8g2提供的测试函数,用于查看显示效果
void draw(u8g2_t *u8g2)
{
u8g2_SetFontMode(u8g2, 1); /*字体模式选择*/
u8g2_SetFontDirection(u8g2, 0); /*字体方向选择*/
u8g2_SetFont(u8g2, u8g2_font_inb24_mf); /*字库选择*/
u8g2_DrawStr(u8g2, 0, 20, "U");
u8g2_SetFontDirection(u8g2, 1);
u8g2_SetFont(u8g2, u8g2_font_inb30_mn);
u8g2_DrawStr(u8g2, 21,8,"8");
u8g2_SetFontDirection(u8g2, 0);
u8g2_SetFont(u8g2, u8g2_font_inb24_mf);
u8g2_DrawStr(u8g2, 51,30,"g");
u8g2_DrawStr(u8g2, 67,30,"\xb2");
u8g2_DrawHLine(u8g2, 2, 35, 47);
u8g2_DrawHLine(u8g2, 3, 36, 47);
u8g2_DrawVLine(u8g2, 45, 32, 12);
u8g2_DrawVLine(u8g2, 46, 33, 12);
u8g2_SetFont(u8g2, u8g2_font_4x6_tr);
u8g2_DrawStr(u8g2, 1,54,"github.com/olikraus/u8g2");
u8g2_SendBuffer(u8g2);
}
2.3 源码加入到MDK编译
1. 在cubemx生成的工程文件夹中,新建一个文件夹名为u8g2,并将之前精简过的csrc中的所有文件拷贝进来。
2. 在keil中加入该文件夹和全部文件:
3. 将include path中包含u8g2的路径
4. main.c文件中#include “u8g2.h”
5. main()函数中结构体一个对象:
6. 调用draw()测试程序
完整main函数如下:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2023 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "tim.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "u8g2.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t u8x8_gpio_and_delay(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
{
switch (msg)
{
case U8X8_MSG_DELAY_100NANO: // delay arg_int * 100 nano seconds
__NOP();
break;
case U8X8_MSG_DELAY_10MICRO: // delay arg_int * 10 micro seconds
for (uint16_t n = 0; n < 320; n++)
{
__NOP();
}
break;
case U8X8_MSG_DELAY_MILLI: // delay arg_int * 1 milli second
HAL_Delay(1);
break;
case U8X8_MSG_DELAY_I2C: // arg_int is the I2C speed in 100KHz, e.g. 4 = 400 KHz
HAL_Delay_us(5);
break; // arg_int=1: delay by 5us, arg_int = 4: delay by 1.25us
case U8X8_MSG_GPIO_I2C_CLOCK: // arg_int=0: Output low at I2C clock pin
if(arg_int == 1)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_6,GPIO_PIN_SET);
}
else if(arg_int == 0)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_6,GPIO_PIN_RESET);
}
break; // arg_int=1: Input dir with pullup high for I2C clock pin
case U8X8_MSG_GPIO_I2C_DATA: // arg_int=0: Output low at I2C data pin
if(arg_int == 1)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_7,GPIO_PIN_SET);
}
else if(arg_int == 0)
{
HAL_GPIO_WritePin(IIC_GPIO_Port, GPIO_PIN_7,GPIO_PIN_RESET);
}
break; // arg_int=1: Input dir with pullup high for I2C data pin
case U8X8_MSG_GPIO_MENU_SELECT:
u8x8_SetGPIOResult(u8x8, /* get menu select pin state */ 0);
break;
case U8X8_MSG_GPIO_MENU_NEXT:
u8x8_SetGPIOResult(u8x8, /* get menu next pin state */ 0);
break;
case U8X8_MSG_GPIO_MENU_PREV:
u8x8_SetGPIOResult(u8x8, /* get menu prev pin state */ 0);
break;
case U8X8_MSG_GPIO_MENU_HOME:
u8x8_SetGPIOResult(u8x8, /* get menu home pin state */ 0);
break;
default:
u8x8_SetGPIOResult(u8x8, 1); // default return value
break;
}
return 1;
}
void draw(u8g2_t *u8g2)
{
u8g2_SetFontMode(u8g2, 1); /*??????*/
u8g2_SetFontDirection(u8g2, 0); /*??????*/
u8g2_SetFont(u8g2, u8g2_font_inb24_mf); /*????*/
u8g2_DrawStr(u8g2, 0, 20, "U");
u8g2_SetFontDirection(u8g2, 1);
u8g2_SetFont(u8g2, u8g2_font_inb30_mn);
u8g2_DrawStr(u8g2, 21,8,"8");
u8g2_SetFontDirection(u8g2, 0);
u8g2_SetFont(u8g2, u8g2_font_inb24_mf);
u8g2_DrawStr(u8g2, 51,30,"g");
u8g2_DrawStr(u8g2, 67,30,"\xb2");
u8g2_DrawHLine(u8g2, 2, 35, 47);
u8g2_DrawHLine(u8g2, 3, 36, 47);
u8g2_DrawVLine(u8g2, 45, 32, 12);
u8g2_DrawVLine(u8g2, 46, 33, 12);
u8g2_SetFont(u8g2, u8g2_font_4x6_tr);
u8g2_DrawStr(u8g2, 1,54,"github.com/olikraus/u8g2");
u8g2_SendBuffer(u8g2);
}
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
u8g2_t u8g2;
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_TIM6_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
u8g2_Setup_ssd1306_i2c_128x64_noname_f(&u8g2, U8G2_R0, u8x8_byte_sw_i2c, u8x8_gpio_and_delay); // ??? u8g2 ???
u8g2_InitDisplay(&u8g2); // ??????????????,??????,?????????
u8g2_SetPowerSave(&u8g2, 0); // ?????
u8g2_ClearBuffer(&u8g2);
draw(&u8g2);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
{
Error_Handler();
}
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 1;
RCC_OscInitStruct.PLL.PLLN = 8;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
完整流程视频: