I'm tryin' to read sensor data from channel AIN0 of ADS1115 using my esp32 where AIN0 is connected with 5V of a power source and the ADS is grounded to this source.
I found the i2c a bit complex (maybe I didnt understand it correctly), I hope you guys could help me.
I'm using I2C_NUM_0 (as a guess, but tried I2C_NUM_1 too) and after using I2C Scanner, I see the ADS sensor is present at address 0x48.
The pins are correct, I've doubled checked it.
So after installing using the follow code:
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#define SDA_PIN 21
#define SCL_PIN 22
#define SENSOR_ADDRESS 0x48
#define ACK_VAL 0x0 /*!< I2C ack value */
#define AIN0_CHANNEL 0x4000
#define WRITE_BIT I2C_MASTER_WRITE /*!< I2C master write */
#define READ_BIT I2C_MASTER_READ /*!< I2C master read */
void install() {
if(!ic2DriverInstalled) {
ESP_LOGI(tag, "Installing...");
i2c_config_t conf;
conf.mode = I2C_MODE_MASTER;
conf.sda_io_num = SDA_PIN;
conf.scl_io_num = SCL_PIN;
conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
conf.master.clk_speed = 100000;
i2c_param_config(I2C_PORT, &conf);
i2c_driver_install(I2C_PORT, I2C_MODE_MASTER, 0, 0, 0);
ic2DriverInstalled = true;
ESP_LOGI(tag, "Installed!");
}
}
When to use and when not to use ACK wasn't understood by me too.
Ok, after installing I run the code to retrieve sensor data. It's something like this:
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esp_err_t read_sensor(uint8_t* data) {
int ret;
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
i2c_master_start(cmd);
i2c_master_write_byte(cmd, SENSOR_ADDRESS << 1 | WRITE_BIT, ACK_VAL);
i2c_master_write_byte(cmd, AIN0_CHANNEL, ACK_VAL);
i2c_master_stop(cmd);
ret = i2c_master_cmd_begin(I2C_PORT, cmd, 1000 / portTICK_RATE_MS);
i2c_cmd_link_delete(cmd);
ESP_LOGD(tag, "RET X1: %d", ret);
if (ret != ESP_OK) {
return ret;
}
vTaskDelay(30 / portTICK_RATE_MS);
cmd = i2c_cmd_link_create();
i2c_master_start(cmd);
i2c_master_write_byte(cmd, SENSOR_ADDRESS << 1 | READ_BIT, ACK_CHECK_EN);
i2c_master_read_byte(cmd, data, ACK_VAL);
i2c_master_stop(cmd);
ret = i2c_master_cmd_begin(I2C_PORT, cmd, 1000 / portTICK_RATE_MS);
i2c_cmd_link_delete(cmd);
ESP_LOGD(tag, "RET X2: %d", ret);
return ret;
}
The first RET print is 0 the second is 263, but I don't have a clue what I'm doing, really.
Is this the correct flow?
1) Write to I2C the address that I want to communicate
2) Write to I2C the address/channel of the sensor that I want to read
3) Read from I2C (in the address that I first used [SENSOR ADDRESS]) the stored value
I really appreciate any help guys.
God Bless.