High-Level Device Layout

This page gives a high-level description of the hardware for this project, including high-level diagrams.

Sensor Node

The sensor node includes the following active components.

sensor_node.png

Active Components

The sensor node is made of the following active components.

  • Accelerometer - The sensor node uses the Kionix KX134-1211 accelerometer to get acceleration data. To cut down on power, there are no vibration analyses run on the sensor node, so raw acceleration data is sent to the gateway. This accelerometer is able to communicate in I2C or SPI, however currently it has only been configured for SPI in the project firmware.
  • Microphone - The sensor node uses the Infineon IM69D130 microphone to get acoustic data. This microphone is only able to send PDM data to the MCU, where it is converted to PCM data. Raw PCM data is then sent to the gateway.
  • Hydrometer - The sensor node uses the Sensirion SHT40 humidity sensor to get ambient humidity data.
  • Temperature Sensor - The sensor node uses a 1kOhm RTD to collect temperature data. This analog signal goes through the MCU analog-to-digital converter (ADC) and temperature data is sent to the gateway.

Passive Components

The sensor node includes the following passive components.

  • Coin-Cell Battery - A replaceable coin-cell battery is used to supply power to this device.
  • Voltage Regulation Circuit - To ensure that the sensors and MCU have a suitable voltage, a buck converter circuit is used to output 3.3V to the 3V rail.
  • Status LED - A status LED is included to provide a visual indication of connection and battery status. (Note: At the time of writing, this has not been incorporated into the code.)

Gateway

The gateway consists of the following hardware components:

gateway.png

Active Components

  • Processor - This gateway uses a Raspbery Pi 4B as the processor. It uses software written primarily in Python.

Passive Components

  • Wall Outlet - The Pi uses a standard 5.1V, 3A wall outlet charger to ensure that its very precise input power requirements are perfectly met.
  • CPU Fan - Due to the heat requirements of the Pi, a small CPU fan is highly recommended to ensure that the Pi will not overheat and shut itself down.

See Also

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