Aku340: Acoustic Noise Sensor; Max44009: Ambient Light Sensor - Bosch XDK110 General Information Manual

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Note: Measurement errors due to self-heating
As any electronic component, the sensor is subject to self-heating, which can be from the sensor
itself, as well as from other components used at the time of measurement. Unfortunately, this self-
heating strongly depends on the usage, and as the XDK can be freely programmed, the self-
heating depends on so many factors that we cannot provide a universal compensation algorithm.
The sensor can be influenced to some extent by the sampling rate and by how fast a reading is
taken after switching it on (see sensor datasheet for details).
For a user-defined program, we suggest monitoring the outside temperature with a reference
thermometer and once a stable offset value is observed, use this to compensate the
measurements. As an indication, a self-heating of 3-4 K under a normal load profile using sensors
and Bluetooth can be expected.
The accuracy of the humidity measurement is strongly related the temperature, as relative humidity
is calculated using the temperature reading. Hence, a higher temperature leads to a lower relative
humidity. Once the temperature compensation is done, the relative humidity can be calculated
using the temperature difference.
For more information please refer to the datasheet:
http://www.bosch-sensortec.com/en/homepage/products_3/environmental_sensors_1/bme280/bme280_1

2.3.6 AKU340: Acoustic Noise Sensor

The XDK is equipped with an AKU340 analog microphone. Due to limitations of the MCU, the
detection of sound patterns (e.g. voice) is not possible. However, the AKU340 can be used as a
sensor to detect ambient noise.
Unfortunately, the current version of the XDK workbench does not contain an implementation of the
noise sensor into the API. However, it is possible to access the device via the following pins:
PD9: AKU340_VDD
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PD4: AKU340_OUT (can be sampled using the analog/digital converter)
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For more information please refer to the datasheet:
http://www.akustica.com/Files/Admin/PDFs/Datasheets/DS26%2D1%2E03%20AKU340%20Datasheet%2Epdf

2.3.7 MAX44009: Ambient Light Sensor

The MAX44009 ambient light sensor is ideal for a number of portable applications such as
smartphones, notebooks, and industrial sensors. At less than 1µA operating current, it is the lowest
power ambient light sensor in the industry and features an ultra-wide 22-bit dynamic range from
0.045 lux to 188,000 lux.
For more information please refer to the datasheet:
http://datasheets.maximintegrated.com/en/ds/MAX44009.pdf
XDK110
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Note: Specifications within this document are subject to change without notice.
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