pcf8574.c

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#include "pcf8574.h"
 
#include "driver/i2c_master.h"
#include "esp_check.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
 
static const char *TAG = "pcf8574";
 
#define I2C_PORT                I2C_NUM_0
 
#define I2C_SCL_GPIO            14
#define I2C_SDA_GPIO            15
 
#define I2C_FREQ_HZ             100000
 
#define I2C_TIMEOUT_MS          1000
 
#define PCF8574_I2C_ADDR        0x20
 
#define LED_CHASE_PIN_COUNT     3
#define LED_CHASE_PIN_MASK      0x07
#define LED_CHASE_PORT_IDLE     0xF8
#define LED_CHASE_STEP_MS       300
 
static i2c_master_bus_handle_t s_i2c_bus;
static i2c_master_dev_handle_t s_pcf8574_dev;
static uint8_t s_port_shadow;
static bool s_initialized;
 
static esp_err_t pcf8574_write_raw(uint8_t value)
{
    return i2c_master_transmit(s_pcf8574_dev, &value, 1, I2C_TIMEOUT_MS);
}
 
static esp_err_t pcf8574_read_raw(uint8_t *value)
{
    return i2c_master_receive(s_pcf8574_dev, value, 1, I2C_TIMEOUT_MS);
}
 
esp_err_t pcf8574_init(void)
{
    if (s_initialized) {
        return ESP_OK;
    }
 
    i2c_master_bus_config_t bus_cfg = {
        .i2c_port = I2C_PORT,
        .sda_io_num = I2C_SDA_GPIO,
        .scl_io_num = I2C_SCL_GPIO,
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .glitch_ignore_cnt = 7,
        .flags.enable_internal_pullup = true,
    };
    ESP_RETURN_ON_ERROR(i2c_new_master_bus(&bus_cfg, &s_i2c_bus), TAG, "i2c bus init failed");
 
    i2c_device_config_t dev_cfg = {
        .dev_addr_length = I2C_ADDR_BIT_LEN_7,
        .device_address = PCF8574_I2C_ADDR,
        .scl_speed_hz = I2C_FREQ_HZ,
    };
    ESP_RETURN_ON_ERROR(i2c_master_bus_add_device(s_i2c_bus, &dev_cfg, &s_pcf8574_dev),
                        TAG, "i2c device add failed");
 
    /* Всее «все»: все пины — вход (1), без активных выходов в 0 */
    s_port_shadow = 0xFF; // все пины входы (1)
    ESP_RETURN_ON_ERROR(pcf8574_write_raw(s_port_shadow), TAG, "initial write failed");
 
    uint8_t readback = 0;
    ESP_RETURN_ON_ERROR(pcf8574_read_raw(&readback), TAG, "initial read failed");
 
    s_initialized = true;
    ESP_LOGI(TAG, "PCF8574 at 0x%02X, I2C SCL=GPIO%d SDA=GPIO%d, port=0x%02X",
             PCF8574_I2C_ADDR, I2C_SCL_GPIO, I2C_SDA_GPIO, readback);
    return ESP_OK;
}
 
esp_err_t pcf8574_write(uint8_t value)
{
    ESP_RETURN_ON_FALSE(s_initialized, ESP_ERR_INVALID_STATE, TAG, "not initialized");
 
    esp_err_t err = pcf8574_write_raw(value);
    ESP_RETURN_ON_ERROR(err, TAG, "write failed");
 
    s_port_shadow = value;
    return ESP_OK;
}
 
esp_err_t pcf8574_read(uint8_t *value)
{
    ESP_RETURN_ON_FALSE(s_initialized, ESP_ERR_INVALID_STATE, TAG, "not initialized");
    ESP_RETURN_ON_FALSE(value, ESP_ERR_INVALID_ARG, TAG, "null value");
 
    return pcf8574_read_raw(value);
}
 
esp_err_t pcf8574_set_pin(uint8_t pin, bool level)
{
    ESP_RETURN_ON_FALSE(pin < 8, ESP_ERR_INVALID_ARG, TAG, "pin out of range");
 
    uint8_t mask = (uint8_t)(1U << pin);
    uint8_t next = s_port_shadow;
 
    if (level) {
        next |= mask;
    } else {
        next &= (uint8_t)~mask;
    }
 
    return pcf8574_write(next);
}
 
esp_err_t pcf8574_get_pin(uint8_t pin, bool *level)
{
    ESP_RETURN_ON_FALSE(pin < 8, ESP_ERR_INVALID_ARG, TAG, "pin out of range");
    ESP_RETURN_ON_FALSE(level, ESP_ERR_INVALID_ARG, TAG, "null level");
 
    uint8_t value = 0;
    ESP_RETURN_ON_ERROR(pcf8574_read(&value), TAG, "read failed");
 
    *level = (value & (1U << pin)) != 0;
    return ESP_OK;
}
 
static void led_chase_task(void *arg)
{
    uint8_t pin = 0;
 
    while (true) {
        uint8_t port = LED_CHASE_PORT_IDLE | (uint8_t)(1U << pin);
        if (pcf8574_write(port) == ESP_OK) {
            ESP_LOGD(TAG, "Chase: P%d on (port=0x%02X)", pin, port);
        }
 
        pin = (uint8_t)((pin + 1) % LED_CHASE_PIN_COUNT);
        vTaskDelay(pdMS_TO_TICKS(LED_CHASE_STEP_MS));
    }
}
 
esp_err_t pcf8574_led_chase_start(void)
{
    static bool started = false;
 
    ESP_RETURN_ON_FALSE(s_initialized, ESP_ERR_INVALID_STATE, TAG, "not initialized");
 
    if (started) {
        return ESP_OK;
    }
 
    BaseType_t created = xTaskCreate(led_chase_task, "led_chase", 2048, NULL, 5, NULL);
    ESP_RETURN_ON_FALSE(created == pdPASS, ESP_ERR_NO_MEM, TAG, "chase task create failed");
 
    started = true;
    ESP_LOGI(TAG, "LED chase started on P0..P%d", LED_CHASE_PIN_COUNT - 1);
    return ESP_OK;
}