diff --git a/drivers/ccs811/doc.txt b/drivers/ccs811/doc.txt index 6ab141b634..aa7a92182d 100644 --- a/drivers/ccs811/doc.txt +++ b/drivers/ccs811/doc.txt @@ -12,22 +12,22 @@ The driver is for the usage with [RIOT-OS](https://github.com/RIOT-OS/RIOT). ## Table of contets 1. [Overview](#overview) - 1. [About the sensor](#about) - 2. [Supported features](#supported) + 1. [About the sensor](#about) + 2. [Supported features](#supported) 2. [Measurement Process](#measurement_process) - 1. [Sensor modes](#sensor_modes) - 2. [Measurement results](#measurement_results) + 1. [Sensor modes](#sensor_modes) + 2. [Measurement results](#measurement_results) 3. [Compensation](#compensation) 4. [Negative Thermal Coefficient Thermistor (NTC)](#ntc) 5. [Interrupts](#interrupts) - 1. [Data ready interrupt](#data_ready_interrupt) - 2. [Threshold interrupt](#threshold interrupt) + 1. [Data ready interrupt](#data_ready_interrupt) + 2. [Threshold interrupt](#threshold interrupt) 6. [Power Saving](#power saving) 7. [Baseline](#baseline) 8. [Error Handling](#error_handling) 19. [Configuration](#configuration) - 1. [Hardware Configurations](#hardware_configuration) - 2. [Driver Configuration Parameters](#driver_configuration) + 1. [Hardware Configurations](#hardware_configuration) + 2. [Driver Configuration Parameters](#driver_configuration) ## Overview    [[TOC](#toc)] @@ -54,26 +54,26 @@ to get CCS811 working. ### Supported Features    [[TOC](#toc)] -@note There are two driver module versions, the ```ccs811``` module -wich provides only basic functionality and the ```ccs811_full``` +@note There are two driver module versions, the `ccs811` module +wich provides only basic functionality and the `ccs811_full` module with additional functionality. -The ```ccs811_full``` module includes the ```ccs811``` module -automatically. If code size is critical, the ```ccs811``` module can -be used, otherwise using the ```ccs811_full``` module is recommended. +The `ccs811_full` module includes the `ccs811` module +automatically. If code size is critical, the `ccs811` module can +be used, otherwise using the `ccs811_full` module is recommended. -The driver supports the following features when modules ```ccs811``` -and ```ccs811_full``` are used. +The driver supports the following features when modules `ccs811` +and `ccs811_full` are used. Feature | Module --------|------- -read raw and converted gas sensor data (eCO2, TVOC) | ```ccs811``` -poling for new sensor gas data | ```ccs811``` -power saving using sleep mode with wakeup | ```ccs811``` -data ready and threshold interrupt handling | ```ccs811_full``` -ambient temperatur calculation with NTC | ```ccs811_full``` -compensate gas readings using an external sensor | ```ccs811_full``` -manual baseline handling | ```ccs811_full``` +read raw and converted gas sensor data (eCO2, TVOC) | `ccs811` +poling for new sensor gas data | `ccs811` +power saving using sleep mode with wakeup | `ccs811` +data ready and threshold interrupt handling | `ccs811_full` +ambient temperatur calculation with NTC | `ccs811_full` +compensate gas readings using an external sensor | `ccs811_full` +manual baseline handling | `ccs811_full` ## Measurement Process    [[TOC](#toc)] @@ -108,12 +108,12 @@ raw data. for 48 hours in the selected mode of operation to ensure sensor performance is stable, see the data sheet for more details. - When the sensor operating mode is changed to a new mode with a lower - sample rate, e.g., from *Pulse Heating Mode* (#CCS811_MODE_10S) to - *Low Power Pulse Heating Mode* (#CCS811_MODE_60S), it should be placed + sample rate, e.g., from *Pulse Heating Mode* (#CCS811_MODE_10S) + to *Low Power Pulse Heating Mode* (#CCS811_MODE_60S), it should be placed in *Idle, Low Current Mode* (#CCS811_MODE_IDLE) for at least 10 minutes before enabling the new mode. When the sensor operating mode is changed - to a new mode with a higher sample rate, e.g., from *Low Power Pulse - Heating Mode* (#CCS811_MODE_60S) to *Pulse Heating Mode* + to a new mode with a higher sample rate, e.g., from + *Low Power Pulse Heating Mode* (#CCS811_MODE_60S) to *Pulse Heating Mode* (#CCS811_MODE_10S), there is no requirement to wait before enabling the new mode. @@ -129,7 +129,7 @@ application can change the measurement mode either Once the measurement mode is set, the user task can use function #ccs811_read_iaq to fetch the results. The function returns **raw data** as well as **Indoor Air Quality (IAQ)** values. If some of the results -are not needed, the corresponding parameters can be set to ```NULL```. +are not needed, the corresponding parameters can be set to `NULL`. While raw data represents simply the current through the sensor and the voltage across the sensor with the selected current, IAQ values are the @@ -187,7 +187,7 @@ If information about the environment like temperature and humidity are available from another sensor, they can be used by CCS811 to compensate gas readings due to temperature and humidity changes. -@note This feature can only be used with the ```ccs811_full``` module. +@note This feature can only be used with the `ccs811_full` module. Function #ccs811_set_environmental_data can be used to set these environmental data. In the following example, the Sensirion SHT3x humidity and @@ -209,7 +209,7 @@ CCS811 supports an external interface for connecting a negative thermal coefficient thermistor (R_NTC) to provide a cost effective and power efficient means of calculating the local ambient temperature. -@note This feature can only be used with the ```ccs811_full``` module. +@note This feature can only be used with the `ccs811_full` module. The sensor measures the voltage V_NTC across R_NTC as well as the voltage V_REF across a connected reference resistor (R_REF). Function #ccs811_read_ntc @@ -217,7 +217,9 @@ can be used at any time to fetch the current resistance of R_NTC. It uses the resistance of R_REF and measured voltages V_REF and V_NTV with the following equation to determine R_NTC: - R_NTC = R_REF / V_REF * V_NTC +``` +R_NTC = R_REF / V_REF * V_NTC +``` Using the data sheet of the NTC, the ambient temperature can be calculated. See application note AMS AN000372 for more details. @@ -254,7 +256,7 @@ CCS811 supports two types of interrupts that can be used to fetch data: - threshold interrupt (#CCS811_INT_THRESHOLD) @note -- Interrupts can only be used with the ```ccs811_full``` module. +- Interrupts can only be used with the `ccs811_full` module. - It is not possible to use both interrupts at the same time. ### Data ready interrupt    [[TOC](#toc)] @@ -338,7 +340,7 @@ value can be saved before the sensor is powered down. This baseline can then be restored with function #ccs811_set_baseline after sensor is powered up again to continue the automatic baseline process. -@note This feature can only be used with the ```ccs811_full``` module. +@note This feature can only be used with the `ccs811_full` module. ## Error Handling    [[TOC](#toc)] @@ -365,7 +367,7 @@ permanently pulled low, leaving the CCS811 and I2C constantly active. +--------+ +--------+ ``` If the interrupt signal **nINT** is used to fetch new data -(only with ```ccs811_full``` module), +(only with `ccs811_full` module), the interrupt pin has to be connected to a GPIO pin. ```