esp-open-rtos/examples/ccs811/ccs811_plus_sht3x/ccs811_plus_sht3x.c

107 lines
3.3 KiB
C
Raw Normal View History

2017-12-11 03:00:53 +00:00
/**
* Simple example with one CCS811 sensor connected to I2C bus 0 and one SHT3x
* sensor to determine ambient temperature. New data are fetched peridically.
*
* Harware configuration:
*
* +------------------------+ +--------+
* | ESP8266 Bus 0 | | CCS811 |
* | GPIO 5 (SCL) >--+----> SCL |
* | GPIO 4 (SDA) ---|-+--- SDA |
* | GND ---|-|--> /WAKE |
* | | | | +--------+
* | | | | | SHT3x |
* | | +----> SCL |
* | | +--- SDA |
* +------------------------+ +--------+
*/
#include "espressif/esp_common.h"
#include "esp/uart.h"
#include "i2c/i2c.h"
#include "FreeRTOS.h"
#include <task.h>
// include CCS811 driver
#include "ccs811/ccs811.h"
// include SHT3x driver
#include "sht3x/sht3x.h"
// define I2C interfaces at which CCS811 and SHT3x sensors are connected
#define I2C_BUS 0
#define I2C_SCL_PIN 5
#define I2C_SDA_PIN 4
static ccs811_sensor_t* ccs811; // CCS811 device data structure
static sht3x_sensor_t* sht3x; // SHT3x device data structure
/*
* User task that fetches the sensor values every 2 seconds.
*/
void user_task(void *pvParameters)
{
uint16_t tvoc;
uint16_t eco2;
float temperature;
float humidity;
// start periodic measurement with 1 measurement per second
ccs811_set_mode (ccs811, ccs811_mode_1s);
// start periodic measurements with 1 measurement per second
sht3x_start_measurement (sht3x, sht3x_periodic_1mps, sht3x_high);
// passive waiting until measurement results are available
vTaskDelay (sht3x_get_measurement_duration (sht3x_high));
TickType_t last_wakeup = xTaskGetTickCount();
while (1)
{
// get the results from CCS811 and do something with them
if (ccs811_get_results (ccs811, &tvoc, &eco2, 0, 0))
printf("%.3f CCS811 Sensor periodic: TVOC %d ppb, eCO2 %d ppm\n",
(double)sdk_system_get_time()*1e-3, tvoc, eco2);
// get the values from SHT3x and do something with them
if (sht3x_get_results (sht3x, &temperature, &humidity))
{
printf("%.3f SHT3x Sensor: %.2f °C, %.2f %%\n",
(double)sdk_system_get_time()*1e-3, temperature, humidity);
// set CCS811 environmental data with values fetched from SHT3x
ccs811_set_environmental_data (ccs811, temperature, humidity);
}
// passive waiting until 2 seconds is over
vTaskDelayUntil(&last_wakeup, 2000 / portTICK_PERIOD_MS);
}
}
void user_init(void)
{
// set UART Parameter
uart_set_baud(0, 115200);
// give the UART some time to settle
sdk_os_delay_us(500);
/** -- MANDATORY PART -- */
// init all I2C bus interfaces at which CCS811 sensors are connected
i2c_init(I2C_BUS, I2C_SCL_PIN, I2C_SDA_PIN, I2C_FREQ_100K);
// longer clock stretching is required for CCS811
i2c_set_clock_stretch (I2C_BUS, CCS811_I2C_CLOCK_STRETCH);
// init the sensors
ccs811 = ccs811_init_sensor (I2C_BUS, CCS811_I2C_ADDRESS_1);
sht3x = sht3x_init_sensor (I2C_BUS, SHT3x_ADDR_2);
if (ccs811 && sht3x)
// create a task that uses the sensor
xTaskCreate(user_task, "user_task", 256, NULL, 2, NULL);
}