Combustion Inc. Android Example

About Combustion Inc.

We build nice things that make cooking more enjoyable. Like a thermometer that's wireless, oven-safe, and uses machine learning to do what no other thermometer can: predict your food’s cooking and resting times with uncanny accuracy.

Our Predictive Thermometer's eight temperature sensors measure the temp outside and inside the food, in the center and at the surface, and nearly everywhere in between. So you know what’s really happening in and around your food. There's a display Timer that's big and bold—legible even through tears of joy and chopped onions—and a mobile app.

Or you can create your own mobile app to work with the Predictive Thermometer using our open source libraries for Android and iOS.

Visit www.combustion.inc to purchase or learn more about the Predictive Thermometer.

Head on over to our FAQ for more product details.

Ask us a quick question on Twitter.

Email [email protected] for OEM partnership information.

Overview

The project is an example Android app for the combustion-android-ble open source library.

The example uses Jetpack Compose and follows Android's Guide to App Architecture with example UI Layer code for interacting with the Combustion Library as the Data Layer.

The example shows how to use the Flow instances produced by the library to handle and present probe data and state updates to your user. If you are looking for more information on how to use our library or the API, head over to the combustion-android-ble repo.

The Application

This example is a fully functional mobile app that interacts with Combustion devices. The app generally follows a list/details information architecture and is organized as follows:

• Devices Screen: The main screen on launch, it shows a card for each device that has been discovered and displays summary measurements in real-time for the device (e.g. instant read, handle, etc.)
• Details Screen: Includes cards for instant read, sensor measurements, line plotting of temperature measurements, and details on the device's configuration and state.
• Settings Screen: For global app settings.

Example Use-Cases

Initialization & Setup

The example uses a single Activity. See the source comments in MainActivity for a walk-through of the following:

• How to initialize the library and start Combustion's Android Service.
• How to create a notification and have the service run in the foreground for long-running use-cases.
• How to discover advertising probes and their temperature readings independent of the service.
• How to request Bluetooth permissions from the user so that your app can access Android Bluetooth resources.
• How to discover devices and be notified of global changes such as Bluetooth on/off and BLE scanning state changes.
• How to create simulated probes to support development without real hardware in the loop.
• How to configure debugging logging from the library.

Device Discovery & State Updates

The example uses a ViewModel to adapt data and state changes produced by the library to the app's View. See the source comments in DevicesViewModel for a walk-through of the following:

• How to subscribe to and handle device discovery events.
• How to connect to and disconnect from temperature probes.
• How to collect probe state and data updates in real-time from the library.
• How to start a transfer of the device's temperature log to the library.
• How to dependency inject the DeviceManager instance into a ViewModel for easier unit testing.

Displaying Data & State

Following the State and Jetpack Compose guidelines, the example shows how to bind the View and probe's state changes using the observables updated by the DevicesViewModel. See the DevicesScreen, ProbeState and DevicesScreenState classes for more details on:

• How to display the real-time temperature updates of a probe.
• How to display Instant Read temperature from the probe.
• How to display probe color and ID values.
• How to monitor the upload progress of a record transfer from a probe.
• How to display a list of all discovered probes.
• How to display static properties of a probe, such as serial number, firmware version and hardware revision.
• How to display dynamic BLE properties of a probe, such as connection state and RSSI.

Service Lifecycle

The DeviceManager class in the framework manages the lifecycle of the CombustionService. The following are lifecycle guidelines for managing the service.

• Call startCombustionService at the point that you want to start consuming the API, for instance from onCreate in your launcher activity.
• Call bindCombustionService at least once, after startCombustionService to establish the connection.
• If the DeviceManager is used across multiple lifecycle components, each component should call bindCombustionService when created and unbindCombustionService when destroyed.
• The DeviceManager maintains a reference count on bindings. After first binding, it will automatically unbind the singleton connection when the reference count reaches 0.
• You can call stopCombustionService to reset the reference count to 0 and stop the service. This will bring the lifecycle to initial state and the earlier steps still apply.

Reporting Issues

Your feedback is important. For reporting issues use the issue tracker.