05 - GPIO 外设
通用输入输出与PWM控制
GPIO 基础
初始化与配置
#include "driver/gpio.h"
// 复位指定GPIO gpio_reset_pin (GPIO_NUM_2);
// 设置方向 gpio_set_direction (GPIO_NUM_2, GPIO_MODE_OUTPUT);
// 设置方向 (输入) gpio_set_direction (GPIO_NUM_4, GPIO_MODE_INPUT);
// 设置上拉/下拉 gpio_set_pull_mode (GPIO_NUM_4, GPIO_PULLUP_ONLY); // 上拉 gpio_set_pull_mode (GPIO_NUM_4, GPIO_PULLDOWN_ONLY); // 下拉 gpio_set_pull_mode (GPIO_NUM_4, GPIO_FLOATING); // 浮空 读写操作
// 输出电平 gpio_set_level (GPIO_NUM_2, 1 ); // 高电平 gpio_set_level (GPIO_NUM_2, 0 ); // 低电平
// 读取电平 int level = gpio_get_level (GPIO_NUM_4);
// 读取模式 gpio_mode_t mode = gpio_get_mode (GPIO_NUM_4); 中断处理
中断配置
#include "driver/gpio.h" #include "esp_intr_alloc.h"
static IRAM_ATTR void gpio_isr_handler ( void * arg ) { uint32_t gpio_num = ( uint32_t ) arg; printf ( "GPIO %d interrupted! \n " , gpio_num); }
void setup_gpio_interrupt ( void ) { gpio_config_t io_conf = { .pin_bit_mask = ( 1 ULL << GPIO_NUM_4), .mode = GPIO_MODE_INPUT, .pull_up_en = GPIO_PULLUP_ENABLE, .pull_down_en = GPIO_PULLDOWN_DISABLE, .intr_type = GPIO_INTR_POSEDGE // 上升沿触发 }; gpio_config ( & io_conf);
gpio_install_isr_service ( 0 ); gpio_isr_handler_add (GPIO_NUM_4, gpio_isr_handler, ( void * ) GPIO_NUM_4); } 中断触发类型
模式 说明 GPIO_INTR_DISABLE 禁用中断 GPIO_INTR_POSEDGE 上升沿触发 GPIO_INTR_NEGEDGE 下降沿触发 GPIO_INTR_ANYEDGE 任意边沿触发 GPIO_INTR_LOW_LEVEL 低电平触发 GPIO_INTR_HIGH_LEVEL 高电平触发
LEDC (PWM)
PWM 输出配置
#include "driver/ledc.h"
void ledc_pwm_init ( void ) { // 配置定时器 ledc_timer_config_t timer_conf = { .speed_mode = LEDC_LOW_SPEED_MODE, .timer_num = LEDC_TIMER_0, .duty_resolution = LEDC_TIMER_8_BIT, // 8位分辨率 (0-255) .freq_hz = 1000 , // 1kHz .clk_cfg = LEDC_AUTO_CLK }; ledc_timer_config ( & timer_conf);
// 配置通道 ledc_channel_config_t channel_conf = { .gpio_num = GPIO_NUM_2, .speed_mode = LEDC_LOW_SPEED_MODE, .channel = LEDC_CHANNEL_0, .timer_sel = LEDC_TIMER_0, .duty = 0 , .hpoint = 0 }; ledc_channel_config ( & channel_conf); }
// 设置占空比 void ledc_set_duty ( uint8_t duty ) { ledc_set_duty (LEDC_LOW_SPEED_MODE, LEDC_CHANNEL_0, duty); ledc_update_duty (LEDC_LOW_SPEED_MODE, LEDC_CHANNEL_0); } 呼吸灯效果
void breathe_ledc ( void ) { int direction = 1 ; int duty = 0 ;
while ( 1 ) { duty += direction * 5 ; if (duty >= 255 ) direction = - 1 ; if (duty <= 0 ) direction = 1 ;
ledc_set_duty (LEDC_LOW_SPEED_MODE, LEDC_CHANNEL_0, duty); ledc_update_duty (LEDC_LOW_SPEED_MODE, LEDC_CHANNEL_0); vTaskDelay ( pdMS_TO_TICKS ( 20 )); } } DAC 输出
数模转换
#include "driver/dac.h"
// 初始化 DAC1 (GPIO25) void dac_init ( void ) { dac_output_enable (DAC_CHANNEL_1); }
// 输出电压 (0-255 对应 0-3.3V) void dac_output ( uint8_t value ) { dac_output_voltage (DAC_CHANNEL_1, value); }
// 输出正弦波示例 void dac_sine_wave ( void ) { int i = 0 ; while ( 1 ) { uint8_t value = ( sin (i * 0.1 ) + 1 ) * 127 ; // 0-254 dac_output_voltage (DAC_CHANNEL_1, value); vTaskDelay ( pdMS_TO_TICKS ( 10 )); i ++ ; } } DAC 参数
通道 GPIO 分辨率 DAC1 GPIO25 8-bit DAC2 GPIO26 8-bit
ADC 采样
模数转换
#include "driver/adc.h" #include "esp_adc_cal.h"
#define ADC_PIN ADC1_CHANNEL_7 // GPIO35
void adc_init ( void ) { adc1_config_width (ADC_WIDTH_BIT_12); // 12位分辨率 adc1_config_channel_atten (ADC_PIN, ADC_ATTEN_DB_11); // 0-3.3V }
uint32_t adc_read ( void ) { return adc1_get_raw (ADC_PIN); }
// 带校准读取 void adc_read_calibrated ( void ) { esp_adc_cal_characteristics_t chars; esp_adc_cal_characterize (ADC_UNIT_1, ADC_ATTEN_DB_11, ADC_WIDTH_BIT_12, 1100 , & chars);
uint32_t voltage = esp_adc_cal_raw_to_voltage ( adc1_get_raw (ADC_PIN), & chars); printf ( "Voltage: %u mV \n " , voltage); } ADC 参数
参数 值 分辨率 9/10/11/12 位 衰减 0-3.3V / 0-2.6V / 0-1.7V / 0-1.1V 采样率 ~ 6kHz
ADC1 通道映射
通道 GPIO 用途 ADC1_CH0 GPIO36 外部输入 ADC1_CH1 GPIO37 外部输入 ADC1_CH2 GPIO38 外部输入 ADC1_CH3 GPIO39 外部输入 ADC1_CH4 GPIO32 外部输入 ADC1_CH5 GPIO33 外部输入 ADC1_CH6 GPIO34 外部输入 ADC1_CH7 GPIO35 外部输入
触摸传感器
#include "driver/touch_pad.h"
void touch_init ( void ) { touch_pad_init (); touch_pad_config (TOUCH_PAD_NUM4, 0 ); // GPIO4 }
void touch_read ( void ) { uint16_t touch_value; touch_pad_read_filtered (TOUCH_PAD_NUM4, & touch_value); printf ( "Touch value: %d\n " , touch_value); } 参考资料
官方文档
技术参考
图片参考
相关链接
反向链接
进阶学习
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