flow3r-openhab/README.md

# flow3r-openhab

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. Copy `flow3r_openhab/config.example.json` to `flow3r_openhab/config.json` and enter your configuration details.
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

## MQTT Topics

* `flow3r-<macaddress>/event`: The app publishes events to this topic. see "Events" below.
* `flow3r-<macaddress>/status`: The app publishes the string `Online` to this topic when started, and submits an `Offline` LWT message.
* `flow3r-<macaddress>/ui_config`: You can publish a label for each petal to this topic, which will be shown on the flow3r's display. See "UI Config" below.

## 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:

```json
{"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`. |


## UI Config

The app subscribes to the topic `flow3r-<macaddress>/ui_config`, at which it listens for JSON arrays such as below:

```json
["I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX", "X"]
```

Each position in the array corrensponds to one of the petals, and the text for each petal is shown on the display close to the corresponding petal.


## Integration into OpenHAB

The following is an example of how this can be integrated into OpenHAB.

The recommended `Thing` definition is as follows:

```yaml
label: flow3r
thingTypeUID: mqtt:topic
configuration:
  availabilityTopic: flow3r-<macaddress>/status
  payloadNotAvailable: Offline
  payloadAvailable: Online
channels:
  - id: event
    channelTypeUID: mqtt:trigger
    label: Event
    configuration:
      stateTopic: flow3r-<macaddress>/event
  - id: ui_config
    channelTypeUID: mqtt:string
    label: UI Config
    configuration:
      commandTopic: flow3r-<macaddress>/ui_config
```

The UI Config can be performed easiest by creating a rule that is triggered by the `Online` message on the status topic:

```yaml
configuration: {}
triggers:
  - id: "1"
    configuration:
      thingUID: mqtt:topic:...
      status: ONLINE
    type: core.ThingStatusUpdateTrigger
conditions: []
actions:
  - inputs: {}
    id: "2"
    configuration:
      itemName: flow3r_ui_config  # item needs to be created and linked to the ui_config topic beforehand
      command: '["I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX", "X"]'
    type: core.ItemCommandAction
```

For handling touch gestures, another rule can be created; the example below runs a JS script that parses the JSON payload and reacts on a long press on petal 10:

```yaml
configuration: {}
triggers:
  - id: "1"
    configuration:
      thingUID: mqtt:topic:...
      channelUID: mqtt:topic:...:event
    type: core.ChannelEventTrigger
conditions: []
actions:
  - inputs: {}
    id: "2"
    type: script.ScriptAction
    configuration:
      type: application/javascript
      script: >-
        var payload = JSON.parse(this.event.event);
        if (payload.petal == "10" and payload.duration > 1000) {
          console.log("longpress!");
        }
```


## License

MIT License

[flow3r]: https://flow3r.garden/
[captouch]: https://docs.flow3r.garden/api/captouch.html#captouch.CaptouchPetalState.position