BME 68x ESP-IDF Component

Fully working, read all parameters correctly. Based on Arduino Lib by Bosch.

Description

1. The componenet depends on my modified i2cdev componment for all i2c bus i/o which can be found here: https://github.com/Rajssss/esp_i2cdev_mod
2. Only I2C support for now
3. Kconfig/menuconfig support is WIP, see #define marcos in bme68xLibrary.cpp file to configure the driver for now.

     
    #define I2C_SDA_GPIO 			40
    #define I2C_SCL_GPIO 			39
    #define I2C_PORT 			0
    #define I2C_BME68x_ADDR		0x76
    #define I2C_FREQ_HZ 			40000
    

4. Tested on ESP-IDF v4.4 (ESP-IDF v4.4-beta1-284-gd83021a6e8-dirty) (release/v4.4 branch)

Example Code for IDF

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include "bme68xLibrary.h"
#include "i2cdev.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "sdkconfig.h"

#define NOP() asm volatile ("nop")

static const char* TAG = "main";

Bme68x bme;
i2c_dev_t dev;


static unsigned long IRAM_ATTR micros()
{
    return (unsigned long) (esp_timer_get_time());
}

static void IRAM_ATTR delayMicroseconds(uint32_t us)
{
    uint32_t m = micros();
    if(us){
        uint32_t e = (m + us);
        if(m > e){ //overflow
            while(micros() > e){
                NOP();
            }
        }
        while(micros() < e){
            NOP();
        }
    }
}


extern "C" void app_main()
{    
	i2cdev_init(); // from i2cdev

	/* initializes the sensor based on SPI library */
	bme.begin(&dev);

	ESP_LOGI(TAG,"checkStatus: %d", bme.checkStatus());

	if(bme.checkStatus())
	{
		ESP_LOGI(TAG,"statusString: %s", bme.statusString());

		if (bme.checkStatus() == BME68X_ERROR)
		{
			ESP_LOGE(TAG,"Sensor error: %s", bme.statusString());
			return;
		}
		else if (bme.checkStatus() == BME68X_WARNING)
		{
			ESP_LOGW(TAG,"Sensor Warning: %s", bme.statusString());
		}
	}

	/* Set the default configuration for temperature, pressure and humidity */
	bme.setTPH();

	/* Set the heater configuration to 300 deg C for 100ms for Forced mode */
	bme.setHeaterProf(300, 100);

	while(1)
	{
		bme68xData data;

		bme.setOpMode(BME68X_FORCED_MODE);
		delayMicroseconds(bme.getMeasDur());

		if (bme.fetchData())
		{
			bme.getData(data);

			ESP_LOGI(TAG,"Temp = %f\n", data.temperature);

			ESP_LOGI(TAG,"Pressure = %f\n", data.pressure);

			ESP_LOGI(TAG,"Humidity = %f\n", data.humidity);

			ESP_LOGI(TAG,"GAS RES = %f\n", data.gas_resistance);
		}
	}
}