CCS811 driver added (#479)
This commit is contained in:
parent
2f62c6e9df
commit
61f23d0cf4
11 changed files with 1989 additions and 0 deletions
examples/ccs811/ccs811_temperature
4
examples/ccs811/ccs811_temperature/Makefile
Normal file
4
examples/ccs811/ccs811_temperature/Makefile
Normal file
|
@ -0,0 +1,4 @@
|
|||
PROGRAM=CCS811_Temperature
|
||||
EXTRA_COMPONENTS = extras/i2c extras/ccs811
|
||||
LIBS ?= gcc hal m
|
||||
include ../../../common.mk
|
131
examples/ccs811/ccs811_temperature/ccs811_temperature.c
Normal file
131
examples/ccs811/ccs811_temperature/ccs811_temperature.c
Normal file
|
@ -0,0 +1,131 @@
|
|||
/**
|
||||
* Simple example with one sensor connected to I2C bus 0. It demonstrates
|
||||
* how to use CCS811 with an external NTC thermistor to determine ambient
|
||||
* temperature.
|
||||
*
|
||||
* Harware configuration:
|
||||
*
|
||||
* +------------------------+ +--------+
|
||||
* | ESP8266 Bus 0 | | CCS811 |
|
||||
* | GPIO 5 (SCL) >----> SCL |
|
||||
* | GPIO 4 (SDA) ------ SDA |
|
||||
* | GND -----> /WAKE |
|
||||
* +------------------------+ +--------+
|
||||
*/
|
||||
|
||||
#include "espressif/esp_common.h"
|
||||
#include "esp/uart.h"
|
||||
#include "i2c/i2c.h"
|
||||
|
||||
#include "FreeRTOS.h"
|
||||
#include <task.h>
|
||||
|
||||
#include <math.h>
|
||||
|
||||
// include CCS811 driver
|
||||
#include "ccs811/ccs811.h"
|
||||
|
||||
// define I2C interfaces at which CCS811 sensors can be connected
|
||||
#define I2C_BUS 0
|
||||
#define I2C_SCL_PIN 5
|
||||
#define I2C_SDA_PIN 4
|
||||
|
||||
|
||||
static ccs811_sensor_t* sensor;
|
||||
|
||||
|
||||
/*
|
||||
* In this example, user task fetches the sensor values every seconds.
|
||||
*/
|
||||
|
||||
// parameters of the Adafruit CCS811 Air Quality Sensor Breakout
|
||||
#define CCS811_R_REF 100000
|
||||
#define CCS811_R_NTC 10000
|
||||
#define CCS811_R_NTC_TEMP 25
|
||||
#define CCS811_BCONSTANT 3380
|
||||
|
||||
void user_task_periodic(void *pvParameters)
|
||||
{
|
||||
uint16_t tvoc;
|
||||
uint16_t eco2;
|
||||
|
||||
TickType_t last_wakeup = xTaskGetTickCount();
|
||||
|
||||
while (1)
|
||||
{
|
||||
// get environmental data from another sensor and set them
|
||||
// ccs811_set_environmental_data (sensor, 25.3, 47.8);
|
||||
|
||||
// get the results and do something with them
|
||||
if (ccs811_get_results (sensor, &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 NTC resistance
|
||||
uint32_t r_ntc = ccs811_get_ntc_resistance (sensor, CCS811_R_REF);
|
||||
|
||||
// calculation of temperature from application note ams AN000372
|
||||
double ntc_temp;
|
||||
ntc_temp = log((double)r_ntc / CCS811_R_NTC); // 1
|
||||
ntc_temp /= CCS811_BCONSTANT; // 2
|
||||
ntc_temp += 1.0 / (CCS811_R_NTC_TEMP + 273.15); // 3
|
||||
ntc_temp = 1.0 / ntc_temp; // 4
|
||||
ntc_temp -= 273.15; // 5
|
||||
|
||||
printf("%.3f CCS811 Sensor temperature: R_NTC %u Ohm, T %f °C\n",
|
||||
(double)sdk_system_get_time()*1e-3, r_ntc, ntc_temp);
|
||||
|
||||
// passive waiting until 1 second is over
|
||||
vTaskDelayUntil(&last_wakeup, 1100 / 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 sensor with slave address CCS811_I2C_ADDRESS_1 connected I2C_BUS.
|
||||
sensor = ccs811_init_sensor (I2C_BUS, CCS811_I2C_ADDRESS_1);
|
||||
|
||||
if (sensor)
|
||||
{
|
||||
#if defined(INT_DATA_RDY_USED) || defined(INT_THRESHOLD_USED)
|
||||
|
||||
// create a task that is resumed by interrupt handler to use the sensor
|
||||
xTaskCreate(user_task_interrupt, "user_task_interrupt", 256, NULL, 2, &nINT_task);
|
||||
|
||||
// set the GPIO and interrupt handler for *nINT* interrupt
|
||||
gpio_set_interrupt(INT_GPIO, GPIO_INTTYPE_EDGE_NEG, nINT_handler);
|
||||
|
||||
#ifdef INT_DATA_RDY_USED
|
||||
// enable the data ready interrupt
|
||||
ccs811_enable_interrupt (sensor, true);
|
||||
#else
|
||||
// set threshold parameters and enable threshold interrupt mode
|
||||
ccs811_set_eco2_thresholds (sensor, 600, 1100, 40);
|
||||
#endif
|
||||
|
||||
#else
|
||||
|
||||
// create a periodic task that uses the sensor
|
||||
xTaskCreate(user_task_periodic, "user_task_periodic", 256, NULL, 2, NULL);
|
||||
|
||||
#endif
|
||||
|
||||
// start periodic measurement with one measurement per second
|
||||
ccs811_set_mode (sensor, ccs811_mode_1s);
|
||||
}
|
||||
}
|
||||
|
Loading…
Add table
Add a link
Reference in a new issue