I'm using the ESP32-S2 on Arduino using the idf-release/v4.2 branch of the arduino-esp32 repository. I'm struggling to read data from an ambient light sensor (Adafruit VEML7700) using the I2C bus. I believe I'm setting up the I2C bus incorrectly, but I'm having difficultly finding answers on the proper way to do this.
If I try to initialize the I2C bus using the example initialization (i2c_master_init) from the ESP-IDF https://github.com/espressif/esp-idf/bl ... ple_main.c, I don't get any errors but all of the sensor readings are 0.
If I try to set up my own Wire instance like in this example https://randomnerdtutorials.com/esp32-i ... duino-ide/, I get this error and all my sensors readings are 0:
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E (6161) i2c: i2c_param_config(644): i2c clock choice is invalid, please check flag and frequencyWhat's the correct way to initialize the I2C bus?
Here's my code, with some of the methods I mentioned above commented out.
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#include "Adafruit_VEML7700.h"
#include "Wire.h"
#include "esp_log.h"
#include "driver/i2c.h"
#define _I2C_NUMBER(num) I2C_NUM_##num
#define I2C_NUMBER(num) _I2C_NUMBER(num)
#define DELAY_TIME_BETWEEN_ITEMS_MS 1000 /*!< delay time between different test items */
#define I2C_MASTER_SCL_IO 9 /*!< gpio number for I2C master clock */
#define I2C_MASTER_SDA_IO 8 /*!< gpio number for I2C master data */
#define I2C_MASTER_NUM I2C_NUMBER(1) /*!< I2C port number for master dev */
#define I2C_MASTER_FREQ_HZ 100000 /*!< I2C master clock frequency */
#define I2C_MASTER_TX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
#define I2C_MASTER_RX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
#define WRITE_BIT I2C_MASTER_WRITE /*!< I2C master write */
#define READ_BIT I2C_MASTER_READ /*!< I2C master read */
#define ACK_CHECK_EN 0x1 /*!< I2C master will check ack from slave*/
#define ACK_VAL 0x0 /*!< I2C ack value */
#define NACK_VAL 0x1 /*!< I2C nack value */
TwoWire I2CWire = TwoWire(0);
Adafruit_VEML7700 veml = Adafruit_VEML7700();
void setup() {
Serial.begin(115200);
delay(3000);
Serial.println("Adafruit VEML7700 Test");
Serial.println("Start I2C setup...");
ESP_ERROR_CHECK(i2c_master_init()); // https://github.com/espressif/esp-idf/blob/master/examples/peripherals/i2c/i2c_self_test/main/i2c_example_main.c
//Wire.begin(8,9);
//I2CWire.begin(I2C_MASTER_SDA_IO, I2C_MASTER_SCL_IO, 100000); //https://randomnerdtutorials.com/esp32-i2c-communication-arduino-ide/
if (!veml.begin()) { // use when ESP_ERROR_CHECK or Wire.begin is uncommented
//if (!veml.begin(&I2CWire)) { // use when I2CWire.begin is uncommented
Serial.println("Sensor not found");
while (1);
}
Serial.println("Sensor found");
veml.setGain(VEML7700_GAIN_1);
veml.setIntegrationTime(VEML7700_IT_800MS);
veml.setLowThreshold(10000);
veml.setHighThreshold(20000);
veml.interruptEnable(true);
}
/**
* @brief i2c master initialization from https://github.com/espressif/esp-idf/blob/master/examples/peripherals/i2c/i2c_self_test/main/i2c_example_main.c
*/
static esp_err_t i2c_master_init(void)
{
int i2c_master_port = I2C_MASTER_NUM;
i2c_config_t conf;
conf.mode = I2C_MODE_MASTER;
conf.sda_io_num = I2C_MASTER_SDA_IO;
conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
conf.scl_io_num = I2C_MASTER_SCL_IO;
conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
conf.master.clk_speed = I2C_MASTER_FREQ_HZ;
conf.clk_flags = 0;
i2c_param_config(i2c_master_port, &conf);
return i2c_driver_install(i2c_master_port, conf.mode, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
}
void loop() {
Serial.print("Lux: "); Serial.println(veml.readLux());
Serial.print("White: "); Serial.println(veml.readWhite());
Serial.print("Raw ALS: "); Serial.println(veml.readALS());
uint16_t irq = veml.interruptStatus();
if (irq & VEML7700_INTERRUPT_LOW) {
Serial.println("** Low threshold");
}
if (irq & VEML7700_INTERRUPT_HIGH) {
Serial.println("** High threshold");
}
Serial.println("\n");
delay(500);
}