MultiGeiger Companion

The MultiGeiger Companion android app can be used for mobile radiation measurements.

Getting Started with MultiGeiger Companion

This app:

• collects data from connected MultiGeiger via Bluetooth®
• displays the data in a chart
• aggregates the data
  • when a certain time (default: 5 min) has passed, or
  • when the location changes (default: ~10 m difference for new position update)
    AND more than a minimum (default: 3) of count rate packets were registered
• sets a marker for every new data aggregation
• shows current position and markers on a map

The current marker collection is not stored on the mobile device, but can be sent via the floating action button by mail.

Screenshot:

Some links:

• Project overview, hardware and embedded ESP32 based firmware development:
  https://github.com/ecocurious2/MultiGeiger
• Map with Multigeiger data:
  https://multigeiger.citysensor.de/
• Ecocurious:
  https://ecocurious.de/
• TTN Region Stuttgart / IoT Makers Region Stuttgart e.V.:
  https://www.thethingsnetwork.org/community/region-stuttgart/

Bluetooth® Communication

BLE Heart Rate Service

The MultiGeiger provides a Bluetooth® Low Energy (BLE) service to allow the collection of the Geiger-Mueller count rate via a GATT Heart Rate Service (Service UUID 0x180D).

The following characteristics are used:

• 0x2A37 ('Heart Rate Measurement Characteristic'):
  • The first byte is a collection of status flags, according to the service's standard
  • 'Heart Rate Measurement' as 16 bit value (little endian), corresponds to Geiger-Mueller counts per minute (CPM)
  • 'Energy Expenditure' as 16 bit value (little endian), represents a rolling packet counter
• 0x2A38 ('Heart Rate Sensor Position Characteristic')
  • 'Sensor Position' as 8 bit value, corresponds to TUBE-TYPE, allowing the conversion of CPM to radiation rate
• 0x2A39 ('Heart Rate Control Point Characteristic')
  • Write characteristic, required by service's standard to reset Energy Expenditure to 0. Writing 0x01 resets the rolling packet counter to 0.

Getting Started with Flutter and this app

A few resources to get you started if this is your first Flutter project:

• Lab: Write your first Flutter app
• Cookbook: Useful Flutter samples

For help getting started with Flutter, view the online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

If you have Flutter up and running the demo successfully, clone this repository, connect your device and execute

flutter run