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README.md

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+# flow3r-mqtt
+
+An app for the CCCamp 2023 [flow3r][flow3r] badge that submits detected touch gestures to an MQTT broker.
+
+I wrote this so that the flow3r can be used as a remote control for
+OpenHAB (which subscribes to the MQTT broker), but it should be usable
+with other subscribers as well.
+
+## Installation
+
+1. Edit `flow3r_openhab/__init__.py` and set the variables `WIFI_SSID`, `WIFI_PSK` and `MQTT_BROKER_IP`.
+1. Copy the `flow3r_openhab` directory to `/sys/apps/flow3r_openhab` on the flow3r's flash filesystem.
+1. Reboot the flow3r and start the `OpenHAB` app
+
+## Events
+
+The touch events detected by the flow3r are published to the topic `flow3r-<macaddress>/event`.
+
+Each event is a JSON string that looks like this:
+
+    {"petal":"2","event":"touch_tip","dx":8083,"dy":6960,"duration":150}
+
+The keys and their values are defined as follows:
+
+| Key | Value |
+|:---|:---|
+| `petal` | The petal the event was detected on.  Uses the numbers printed on the PCB (1-10), rather than the `captouch` indexes (0-9). |
+| `event` | The type of gesture that was detected.  One of `touch_tip`, `touch_base`, `swipe_up`, `swipe_right`, `swipe_down`, swipe_left`, whereas `swipe_up` always means a swipe towards the tip of the petal, and `swipe_down towards its base. |
+| `dx` | The distance between start and end of the touch event in `x` (base-to-tip) direction.  Unitless number, as returned by [captouch's `position()` function][captouch]. |
+| `dy` | The distance between start and end of the touch event in `y` (side-to-side) direction. |
+| `duration` | The duration between start and end of the touch event in `ms`. |
+
+
+## License
+
+MIT License
+
+[flow3r]: https://flow3r.garden/
+[captouch]: https://docs.flow3r.garden/api/captouch.html#captouch.CaptouchPetalState.position