pca9535.c

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#include "pca9535.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 = "pca9535";
 
#define I2C_PORT                I2C_NUM_0
#define I2C_SCL_GPIO            14
#define I2C_SDA_GPIO            15
#define I2C_FREQ_HZ             400000
#define I2C_TIMEOUT_MS          1000
 
#define PCA9535_I2C_ADDR        0x20
 
#define PCA9535_REG_INPUT0      0x00
#define PCA9535_REG_INPUT1      0x01
#define PCA9535_REG_OUTPUT0     0x02
#define PCA9535_REG_OUTPUT1     0x03
#define PCA9535_REG_INVERT0     0x04
#define PCA9535_REG_INVERT1     0x05
#define PCA9535_REG_CONFIG0     0x06
#define PCA9535_REG_CONFIG1     0x07
 
#define LED_P03_BIT             (1U << 3)
#define LED_P04_BIT             (1U << 4)
#define LED_MASK                (LED_P03_BIT | LED_P04_BIT)
 
#define PORT0_CONFIG_LEDS       0xE7
 
#define TEST_BLINK_MS           400
 
static i2c_master_bus_handle_t s_i2c_bus;
static i2c_master_dev_handle_t s_pca9535_dev;
static uint8_t s_output0;
static bool s_initialized;
 
static esp_err_t pca9535_write_reg(uint8_t reg, uint8_t value)
{
    uint8_t buf[2] = {reg, value};
    return i2c_master_transmit(s_pca9535_dev, buf, sizeof(buf), I2C_TIMEOUT_MS);
}
 
static esp_err_t pca9535_read_reg(uint8_t reg, uint8_t *value)
{
    return i2c_master_transmit_receive(s_pca9535_dev, &reg, 1, value, 1, I2C_TIMEOUT_MS);
}
 
static esp_err_t pca9535_set_port0(uint8_t value)
{
    ESP_RETURN_ON_ERROR(pca9535_write_reg(PCA9535_REG_OUTPUT0, value), TAG, "write output0 failed");
    s_output0 = value;
    return ESP_OK;
}
 
esp_err_t pca9535_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 = PCA9535_I2C_ADDR,
        .scl_speed_hz = I2C_FREQ_HZ,
    };
    ESP_RETURN_ON_ERROR(i2c_master_bus_add_device(s_i2c_bus, &dev_cfg, &s_pca9535_dev),
                        TAG, "i2c device add failed");
 
    ESP_RETURN_ON_ERROR(pca9535_write_reg(PCA9535_REG_INVERT0, 0x00), TAG, "invert0 failed");
    ESP_RETURN_ON_ERROR(pca9535_write_reg(PCA9535_REG_INVERT1, 0x00), TAG, "invert1 failed");
    ESP_RETURN_ON_ERROR(pca9535_write_reg(PCA9535_REG_CONFIG0, PORT0_CONFIG_LEDS),
                        TAG, "config0 failed");
    ESP_RETURN_ON_ERROR(pca9535_write_reg(PCA9535_REG_CONFIG1, 0xFF), TAG, "config1 failed");
    ESP_RETURN_ON_ERROR(pca9535_set_port0(0x00), TAG, "output0 failed");
 
    uint8_t config0 = 0;
    ESP_RETURN_ON_ERROR(pca9535_read_reg(PCA9535_REG_CONFIG0, &config0), TAG, "read config0 failed");
 
    s_initialized = true;
    ESP_LOGI(TAG, "PCA9535 at 0x%02X, %u Hz, SCL=GPIO%d SDA=GPIO%d, config0=0x%02X",
             PCA9535_I2C_ADDR, I2C_FREQ_HZ, I2C_SCL_GPIO, I2C_SDA_GPIO, config0);
    return ESP_OK;
}
 
static void pca9535_test_task(void *arg)
{
    const uint8_t patterns[] = {LED_P03_BIT, LED_P04_BIT};
    size_t idx = 0;
 
    while (true) {
        uint8_t port = patterns[idx];
        if (pca9535_set_port0(port) == ESP_OK) {
            ESP_LOGI(TAG, "Test LED port0=0x%02X", port);
        }
 
        idx = (idx + 1) % (sizeof(patterns) / sizeof(patterns[0]));
        vTaskDelay(pdMS_TO_TICKS(TEST_BLINK_MS));
    }
}
 
esp_err_t pca9535_test_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(pca9535_test_task, "pca9535_test", 2048, NULL, 5, NULL);
    ESP_RETURN_ON_FALSE(created == pdPASS, ESP_ERR_NO_MEM, TAG, "test task create failed");
 
    started = true;
    ESP_LOGI(TAG, "Test task started: LEDs on P0.3 and P0.4");
    return ESP_OK;
}