| Title: Environmental Sensing |
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| Description: |
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| This sample is a simple environmental sensing service for the Arduino 101 board. |
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| The ARC application collects temperature, humidity and pressure data from |
| a set of sensors connected to the Arduino 101 and sends it to the x86 core |
| through IPM. The colected sensor data is also displayed by the ARC core on |
| a Grove LCD. |
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| The x86 application exposes the received sensor data as a simple Bluetooth |
| Environmental Sensing Service. |
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| Sensor wiring: |
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| The sample uses the HDC1008 sensor for temperature and humidity measurement, and |
| the BMP280 sensor for pressure measurement. This section describes how to wire |
| these sensors to the Arduino 101 board. |
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| Both sensors operate at 3.3V and use I2C to comunicate with the Arduino. On the |
| Arduino 101, the I2C data pin (SDA) is exposed as pin A4 (on the ANALOG IN header) |
| and the I2C clock pin (SCL) as pin A5 (also on the ANALOG IN header). Since the |
| Arduino 101 doesn't have internal pull-up resitors, these need to be added externally |
| when connecting SCL and SDA to the sensors. |
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| In addition to connecting the ground (GND), 3.3V power (VDD and VDDIO) and I2C |
| pins, both HDC1008 and BMP280 require some extra wiring. |
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| For HDC1008, connect the address pins (A0 and A1) to GND (this sets the device |
| address to the default used by the app). Also connect the RDY pin of the sensor |
| to the A1 pin (on ANALOG IN header) of the Arduino board. This is needed as the |
| app configures data-ready interrupt on that pin (GPIO pin 3). |
| |
| For BMP280, connect the SDO pin to GND and the CSB pin to VDDIO, since the sensor |
| needs to be setup to use I2C, and not SPI. |
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| Internal sensor: |
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| If you do not want to use any external sensors, you can use the Arduino 101's internal |
| BMI160 sensor to do just temperature readings. To do this, you need to modify the |
| channel_info array from the ARC application to contain only BMI160's temperature channel, |
| and also remove the humidity and pressure characteristic from the x86 application. |
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| If you choose this approach and you also want to use the Grove LCD, then you also need |
| to modify the ARC application to only display temperature on the LCD, as humidity and |
| pressure values will not be available. |
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| --------------------------------------------------------------------------------------------------- |
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| Grove LCD: |
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| Using the Grove LCD is optional and it can be disabled by removing the Grove configuration |
| options from the arc/proj.conf file. |
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| The Grove LCD communcicates with the ARC core though the I2C bus. When connecting the Grove |
| LCD to the Arduino 101, either directly (similar to sensor wiring) or through a Grove Base |
| Shield, you need to make sure that the I2C SDA and SCL lines have pull-up resistors connected |
| between GND and the 3.3V power source. |
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| Take note that even though SDA and SCL are connected to a 3.3V power source, the Grove LCD |
| VDD line needs to be connected to the 5V power line, otherwise characters will not be displayed |
| on the LCD (3.3V is enough to power just the backlight). |