Added CCS811 library.

CMakeLists.txt

@@ -50,6 +50,7 @@ set(C_LIBRARIES
     "lvgl"
     "st7789"
     "bme280"
+    "ccs811"
 )
 
 add_subdirectory(lib)

lib/CMakeLists.txt

@@ -25,3 +25,11 @@ set(BME280_DHT_SOURCES
 
 add_library(bme280 STATIC ${BME280_DHT_SOURCES})
 target_compile_definitions(bme280 PRIVATE ${BME280_DHT_DEFINES})
+
+set(CCS811_TVOC_SOURCES
+    "ccs811_tvoc/ccs811_tvoc.c"
+)
+
+add_library(ccs811 STATIC ${CCS811_TVOC_SOURCES})
+target_compile_definitions(ccs811 PRIVATE ${CCS811_TVOC_DEFINES})
+

lib/ccs811_tvoc/ccs811_tvoc.c

@@ -0,0 +1,66 @@
+#include "ccs811_tvoc.h"
+
+ccs811_ret_t _ccs811_sw_reset(ccs811_t *ccs);
+ccs811_ret_t _ccs811_app_start(ccs811_t *ccs);
+ccs811_ret_t _ccs811_set_mode(ccs811_t *ccs, uint8_t mode);
+
+
+ccs811_ret_t ccs811_init(ccs811_t *ccs, uint8_t addr, void *arg) {
+    if(_ccs811_sw_reset(ccs) == CCS_FAIL) return CCS_FAIL;
+    ccs->cb.delay_ms_cb(ccs->user_data, 5);
+    if(_ccs811_app_start(ccs) == CCS_FAIL) return CCS_FAIL;
+    ccs->cb.delay_ms_cb(ccs->user_data, 5);
+    if(_ccs811_set_mode(ccs, 0x01) == CCS_FAIL) return CCS_FAIL;
+    return CCS_OK;
+}
+
+ccs811_ret_t ccs811_set_env_data(ccs811_t *ccs, double temperature, double humidity) {
+    uint16_t temp_in_512 = (uint16_t)((temperature + 25.0) * 512.0);
+    uint16_t humid_in_512 = (uint16_t)(humidity * 512.0);
+    uint8_t env_data[4] = {humid_in_512 >> 0x08, humid_in_512 & 0xFF, temp_in_512 >> 0x08, temp_in_512 & 0xFF};
+    return ccs->cb.write_register_cb(ccs->user_data, 0x05, env_data, 0x04);
+}
+
+ccs811_ret_t ccs811_read_baseline(ccs811_t *ccs, uint8_t *baseline) {
+    ccs->cb.read_register_cb(ccs->user_data, 0x11, baseline, 0x02);
+    return CCS_OK;
+}
+
+ccs811_ret_t ccs811_store_baseline(ccs811_t *ccs, uint8_t *baseline) {
+    ccs->cb.write_register_cb(ccs->user_data, 0x11, baseline, 0x02);
+    return CCS_OK;
+}
+
+ccs811_ret_t ccs811_measure(ccs811_t *ccs, ccs811_result_t *result) {
+    uint8_t alg_result[8];
+    uint8_t loop_count = 0;
+    do {
+        ccs->cb.read_register_cb(ccs->user_data, 0x02, alg_result, 0x08);
+        ccs->cb.delay_ms_cb(ccs->user_data, 100);
+        loop_count++;
+    } while(((alg_result[4] & 0x08) == 0) && (loop_count < 12));
+    result->eco2 = alg_result[0] << 0x08 | alg_result[1];
+    result->tvoc = alg_result[2] << 0x08 | alg_result[3];
+    return CCS_OK;
+}
+
+ccs811_ret_t _ccs811_sw_reset(ccs811_t *ccs) {
+    uint8_t magic[4] = {0x11, 0xE5, 0x72, 0x8A};
+    return ccs->cb.write_register_cb(ccs->user_data, 0xFF, magic, 0x04);
+}
+
+ccs811_ret_t _ccs811_app_start(ccs811_t *ccs) {
+    uint8_t status;
+    if(ccs->cb.read_register_cb(ccs->user_data, 0x00, &status, 0x01) == CCS_FAIL) {
+        return CCS_FAIL;
+    }
+    if(status & 0x10 == 0) {
+        return CCS_FAIL;
+    }
+    return ccs->cb.write_register_cb(ccs->user_data, 0xF4, (uint8_t *)0x00, 0x00);
+}
+
+ccs811_ret_t _ccs811_set_mode(ccs811_t *ccs, uint8_t mode) {
+    uint8_t drive_mode = mode << 0x04;
+    return ccs->cb.write_register_cb(ccs->user_data, 0x01, &drive_mode, 0x01);
+}

lib/ccs811_tvoc/ccs811_tvoc.h

@@ -0,0 +1,35 @@
+#ifndef __I2CDEV_CCS811_H
+#define __I2CDEV_CCS811_H
+
+#include <stdint.h>
+
+#define CCS_OK 0
+#define CCS_FAIL -1
+
+typedef int ccs811_ret_t;
+
+typedef struct {
+    uint16_t eco2;
+    uint16_t tvoc;
+} ccs811_result_t;
+
+typedef struct {
+    ccs811_ret_t (*set_nwake_cb)(void *handle, uint8_t is_awake);
+    ccs811_ret_t (*delay_ms_cb)(void *handle, uint32_t msec);
+    ccs811_ret_t (*read_register_cb)(void *handle, uint8_t reg, uint8_t *data, uint8_t len);
+    ccs811_ret_t (*write_register_cb)(void *handle, uint8_t reg, uint8_t *data, uint8_t len);
+} ccs811_cb_t;
+
+typedef struct {
+    uint16_t baseline;
+    void *user_data;
+    ccs811_cb_t cb;
+} ccs811_t;
+
+ccs811_ret_t ccs811_init(ccs811_t *ccs, uint8_t addr, void *arg);
+ccs811_ret_t ccs811_set_env_data(ccs811_t *ccs, double temperature, double humidity);
+ccs811_ret_t ccs811_read_baseline(ccs811_t *ccs, uint8_t *baseline);
+ccs811_ret_t ccs811_store_baseline(ccs811_t *ccs, uint8_t *baseline);
+ccs811_ret_t ccs811_measure(ccs811_t *ccs, ccs811_result_t *result);
+
+#endif

src/tasks/user_dht_task.c

@@ -53,4 +53,4 @@ void *user_dht_task(void *arguments) {
         USER_LOG(USER_LOG_INFO, "BME: %.02f, %.02f, %.02f", res.temperature, res.humidity, res.pressure);
         sleep(1);
     }
-}
+}