Telemetry end-to-end

For running the sensor firmware, you will need a micro:bit v2. Unfortunately, the example does not work with earlier versions of the micro:bit. It also does not work with other boards, like e.g. the Raspberry Pi Pico (which doesn’t have Bluetooth), or the ESP32 (which has different CPU architecture: Xtensa or RISC-V). As also the Bluetooth driver is part of the firmware, you cannot simply flash it to a different ARM based device.

However, as the overall example is only relying on Bluetooth, GATT, and the micro:bit temperature profile. You can of course drop in your down device, as long it is implementing the same profile.

One alternative to achieve the same, is to use “Make Code” with this example project.

To install the firmware on the micro:bit, you can either use pre-compiled HEX file, or build the firmware using the Rust toolchain.

Option 1: Installing pre-compiled firmware

The easiest way to get started is to download the pre-compiled firmware here. When powering on your micro:bit, it should attach itself as a USB storage device. Copy the downloaded file to the MICROBIT folder. Once the file ‘disappears’ from the folder, the firmware is installed. For more details, have a look at the https://microbit.org/get-started/first-steps/set-up/.

Once installed, the text ‘Hello, Drogue’ should slide across the LED matrix display of the micro:bit.

Option 2: Building firmware from scratch

Before continuing, make sure your micro:bit is loaded with the default firmware (If you get the noisy greeting when starting the device, you probably have the default firmware).

Reset micro:bit to factory defaults

To reset the micro:bit to factory defaults, use this link for downloading the “Out of the box” firmware.

When powering on your micro:bit, it should attach itself as a USB storage device. Copy the downloaded file to the MICROBIT folder. Once the file ‘disappears’ from the folder, the firmware is installed, and the micro:bit should be making some noise. For more details, have a look at the https://microbit.org/get-started/first-steps/set-up/.

Install Rust

In order to install Rust, installing rustup is sufficient on most cases:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Clone the firmware repository

git clone https://github.com/drogue-iot/drogue-device.git
git checkout 0.4.0

Flash the device

Attach the device to your USB port and execute the following command to build and flash the firmware:

cd examples/nrf/microbit/ble-temperature
cargo run --release

Once the device is flashed, it will start to announce its services using Bluetooth.

What is next?