reTerminalとは5インチのタッチスクリーン付きのRaspberry Piです。Raspberry Pi Compute Module 4を内蔵できます。Switch Scienceや秋月電子通商で売られているものは、メモリが4GBで32GB eMMCストレージ、Wi-Fi、Bluetoothがついたモデルです。技適マークも付いています。
enebular-agentをインストール
reTerminalは、最初からRaspberryPi OS Busterがインストールされていました。タッチスクリーンが初期状態で動作するので、キーボードを用意すればWi-Fiの設定等の初期セットアップが行なえます。
enebular-agentも特に問題なくインストールができました。（enebular-agentのインストール方法は「enebular-agentをRaspberry Piにインストールする」を参照下さい）
センサー値を可視化
ディスプレイ付きということで、単純にDashboardを使って、センサーから取得できる値をゲージやグラフで表示させてみます。
センサー
センサーはオムロンのUSB型環境センサー 2JCIE-BU01を使用します。
USBに指すことで、温度、湿度、照度、気圧、騒音、3軸加速度、eTVOC（室内環境下における総揮発性有機化合物濃度）が取得できます。
以下のブログ記事にNode-REDでの使用方法が書かれています。
事前準備
センサーを使うために事前に設定が必要になります。センサーをreTerminalのUSBに刺した状態で、以下のコマンドを順に LXTerminalで実行します。
$ sudo su
$ modprobe ftdi_sio
$ echo "0590 00d4" > /sys/bus/usb-serial/drivers/ftdi_sio/new_id
$ cd /etc/udev/rules.d/
$ echo "ACTION==\"add\", ATTRS{idVendor}==\"0590\", ATTRS{idProduct}==\"00d4\", RUN+=\"/sbin/modprobe ftdi_sio\" RUN+=\"/bin/sh -c 'echo 0590 00d4 > /sys/bus/usb-serial/drivers/ftdi_sio/new_id'\"" >> 80-rename-2JCIE-BU.rules
フロー
フローは単純に1秒周期でセンサーから取得した値（温度、湿度、気圧、騒音）をDashboardのゲージノードとグラフノードで表示しているだけです。reTerminalが起動したら表示するように内蔵しているChromiumブラウザを起動し、Dashboardを表示するようにしています。これは、以前書いた記事と同様です。詳細な説明は以下を確認して下さい。
作ったフローはenebularのDiscoverで公開しています。
https://enebular.com/discover/flow/bdb14ab9-4e41-474a-8442-21f26f7a1418
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動作確認
enebularからフローをデプロイして、動作確認します。デプロイしてフローが動作すれば、Dashboardが表示されました。
最後に
Node-REDのDashboardで簡単にUIを作れるので、reTerminalとの相性は良いですね。いろいろなケースのアプリケーションが想像できます。
reTerminal内臓のセンサー（3軸加速度、環境光）やボタン、ブザー、タッチ位置を扱うためのノードも見つけました。こちらも活用して他にも作って記事にしたいと思います。
※本記事は、enebular公式に動作を保証するものではありません。