initial display readme

display/README.md

@@ -1,5 +1,35 @@
+# Alert-Me Display
+
+A simple application for an
+[nRF52840](https://www.nordicsemi.com/Products/nRF52840) microcontroller using
+[embassy](https://embassy.dev/).
+
+It consists of multiple parts:
+
+- Configuration interface leveraging BLE
+- Connect to WiFi in order subscribe to a configured MQTT topic
+- Show information on an LCD screen
+
+This is a learning environment, not a finished product.
+
+# Development
+
+## Nix
+
+If using the nix way as described in the [top-level readme](../README.md), no
+further dependencies need to be installed.
+
+## Manual Way
+
+In addition to the [top-level readme](../README.md) dependencies, the following
+has to be installed:
+
+- [probe-rs](https://probe.rs/docs/getting-started/installation/)
+
+## Softdevice
+
 The softdevice blob is not distributed with this repository for licensing
-reasons (even though it would be possible if my understanding is correct).
+reasons (even though my understanding is that it is possible).
 
 Download the
 [S140 Softdevice](https://www.nordicsemi.com/Products/Development-software/s140/download)
@@ -10,3 +40,10 @@ _Example command to flash the softdevice_
 ```
 probe-rs download --verify --format hex --chip nRF52840_xxAA ./s140_nrf52_7.3.0_softdevice.hex
 ```
+
+## Running
+
+Verify that the microcontrolleris recognized by running `probe-rs list`.
+
+A simple `cargo run` will then connect to it and upload the code. Logging output
+should be visible.