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在AT-START-L021开发板上配有ArduinoTM Uno R3扩展接口，合理地所用它可起到事半功倍的效果。这里以一款I2C接口的OLED屏显示驱动为例来进行介绍，为了借用图1所示的扩展接口从而免去接线的问题，故OLED屏与开发板的连接关系为： SCL---PA5 SDA---PA6
图1 所用接口 使这2个引脚输出高低电平的语句定义为： #define OLED_SCLK_Clr() gpio_bits_write(GPIOA,GPIO_PINS_5,FALSE) #define OLED_SCLK_Set() gpio_bits_write(GPIOA,GPIO_PINS_5,TRUE) #define OLED_SDIN_Clr() gpio_bits_write(GPIOA,GPIO_PINS_6,FALSE) #define OLED_SDIN_Set() gpio_bits_write(GPIOA,GPIO_PINS_6,TRUE) 配置这2个引脚为输出功能的函数为： - void oled_CONFIG(void)
- {
- gpio_init_type gpio_init_struct;
- crm_periph_clock_enable(CRM_GPIOA_PERIPH_CLOCK, TRUE);
- gpio_default_para_init(&gpio_init_struct);
- gpio_init_struct.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
- gpio_init_struct.gpio_out_type = GPIO_OUTPUT_PUSH_PULL;
- gpio_init_struct.gpio_mode = GPIO_MODE_OUTPUT;
- gpio_init_struct.gpio_pins = GPIO_PINS_5|GPIO_PINS_6;
- gpio_init_struct.gpio_pull = GPIO_PULL_NONE;
- gpio_init(GPIOA, &gpio_init_struct);
- }
该显示屏的初始化函数为： - void OLED_Init(void)
- {
- Write_IIC_Command(0xAE);
- Write_IIC_Command(0x20);
- Write_IIC_Command(0x10);
- Write_IIC_Command(0xb0);
- Write_IIC_Command(0xc8);
- Write_IIC_Command(0x00);
- Write_IIC_Command(0x10);
- Write_IIC_Command(0x40);
- Write_IIC_Command(0x81);
- Write_IIC_Command(0xdf);
- Write_IIC_Command(0xa1);
- Write_IIC_Command(0xa6);
- Write_IIC_Command(0xa8);
- Write_IIC_Command(0x3F);
- Write_IIC_Command(0xa4);
- Write_IIC_Command(0xd3);
- Write_IIC_Command(0x00);
- Write_IIC_Command(0xd5);
- Write_IIC_Command(0xf0);
- Write_IIC_Command(0xd9);
- Write_IIC_Command(0x22);
- Write_IIC_Command(0xda);
- Write_IIC_Command(0x12);
- Write_IIC_Command(0xdb);
- Write_IIC_Command(0x20);
- Write_IIC_Command(0x8d);
- Write_IIC_Command(0x14);
- Write_IIC_Command(0xaf);
- }
实现清屏处理的函数为： - void OLED_Clear(void)
- {
- uint8_t i,n;
- for(i=0;i<8;i++)
- {
- OLED_WR_Byte (0xb0+i,OLED_CMD);
- OLED_WR_Byte (0x00,OLED_CMD);
- OLED_WR_Byte (0x10,OLED_CMD);
- for(n=0;n<128;n++)OLED_WR_Byte(0,OLED_DATA);
- }
- }
实现字符串显示功能的函数为： - void OLED_ShowString(uint8_t x,uint8_t y,uint8_t *chr,uint8_t 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++;
- }
- }
显示显示功能测试的主程序为： - int main(void)
- {
- system_clock_config();
- at32_board_init();
- oled_CONFIG();
- OLED_Init();
- OLED_Clear();
- OLED_ShowString(0,0,"AT32L021 TEST",16);
- OLED_ShowString(0,2,"OLED DISPLAY",16);
- OLED_ShowString(0,4,"jinglixixi",16);
- OLED_ShowString(0,6,"2024.11.28",16);
- while(1)
- {
- at32_led_toggle(LED2);
- delay_ms(200);
- at32_led_toggle(LED3);
- delay_ms(200);
- at32_led_toggle(LED4);
- delay_ms(200);
- }
- }
经程序的编译与下载，其显示效果如图2所示。 图2 显示效果
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