106 lines
3.3 KiB
C
106 lines
3.3 KiB
C
/**
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* Simple example with one CCS811 sensor connected to I2C bus 0 and one SHT3x
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* sensor to determine ambient temperature. New data are fetched peridically.
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*
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* Harware configuration:
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*
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* +------------------------+ +--------+
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* | ESP8266 Bus 0 | | CCS811 |
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* | GPIO 14 (SCL) ---+----> SCL |
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* | GPIO 13 (SDA) <--|-+--> SDA |
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* | GND ---|-|--> /WAKE |
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* | | | | +--------+
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* | | | | | SHT3x |
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* | | +----> SCL |
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* | | +--> SDA |
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* +------------------------+ +--------+
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*/
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#include "espressif/esp_common.h"
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#include "esp/uart.h"
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#include "i2c/i2c.h"
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#include "FreeRTOS.h"
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#include <task.h>
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// include CCS811 driver
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#include "ccs811/ccs811.h"
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// include SHT3x driver
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#include "sht3x/sht3x.h"
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// define I2C interfaces at which CCS811 and SHT3x sensors are connected
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#define I2C_BUS 0
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#define I2C_SCL_PIN 14
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#define I2C_SDA_PIN 13
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static ccs811_sensor_t* ccs811; // CCS811 device data structure
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static sht3x_sensor_t* sht3x; // SHT3x device data structure
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/*
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* User task that fetches the sensor values every 2 seconds.
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*/
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void user_task(void *pvParameters)
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{
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uint16_t tvoc;
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uint16_t eco2;
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float temperature;
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float humidity;
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// start periodic measurement with 1 measurement per second
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ccs811_set_mode (ccs811, ccs811_mode_1s);
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// start periodic measurements with 1 measurement per second
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sht3x_start_measurement (sht3x, sht3x_periodic_1mps, sht3x_high);
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// passive waiting until measurement results are available
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vTaskDelay (sht3x_get_measurement_duration (sht3x_high));
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TickType_t last_wakeup = xTaskGetTickCount();
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while (1)
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{
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// get the results from CCS811 and do something with them
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if (ccs811_get_results (ccs811, &tvoc, &eco2, 0, 0))
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printf("%.3f CCS811 Sensor periodic: TVOC %d ppb, eCO2 %d ppm\n",
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(double)sdk_system_get_time()*1e-3, tvoc, eco2);
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// get the values from SHT3x and do something with them
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if (sht3x_get_results (sht3x, &temperature, &humidity))
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{
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printf("%.3f SHT3x Sensor: %.2f °C, %.2f %%\n",
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(double)sdk_system_get_time()*1e-3, temperature, humidity);
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// set CCS811 environmental data with values fetched from SHT3x
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ccs811_set_environmental_data (ccs811, temperature, humidity);
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}
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// passive waiting until 2 seconds is over
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vTaskDelayUntil(&last_wakeup, 2000 / portTICK_PERIOD_MS);
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}
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}
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void user_init(void)
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{
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// set UART Parameter
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uart_set_baud(0, 115200);
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// give the UART some time to settle
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sdk_os_delay_us(500);
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/** -- MANDATORY PART -- */
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// init all I2C bus interfaces at which CCS811 sensors are connected
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i2c_init(I2C_BUS, I2C_SCL_PIN, I2C_SDA_PIN, I2C_FREQ_100K);
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// longer clock stretching is required for CCS811
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i2c_set_clock_stretch (I2C_BUS, CCS811_I2C_CLOCK_STRETCH);
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// init the sensors
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ccs811 = ccs811_init_sensor (I2C_BUS, CCS811_I2C_ADDRESS_1);
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sht3x = sht3x_init_sensor (I2C_BUS, SHT3x_ADDR_2);
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if (ccs811 && sht3x)
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// create a task that uses the sensor
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xTaskCreate(user_task, "user_task", 256, NULL, 2, NULL);
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}
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