2.3 KiB
node-red-node-arduino
A Node-RED node to talk to an Arduino running standard firmata 2.2 or better.
Install
Run the following command in the root directory of your Node-RED install, usually
this is ~/.node-red
npm install node-red-node-arduino
Usage
The Firmata firmware must be loaded into the Arduino.
See the main documentation for details and examples of how to use this node.
Input Node
Connects to local Arduino and monitors the selected pin for changes.
You can select either Digital or Analogue input type. Outputs the value read as msg.payload and the pin number as msg.topic.
It only outputs on a change of value - fine for digital inputs, but you can get a lot of data from analogue pins which you must then handle.
You can set the sample rate from 20 to 65535 mS.
Output Node
Connects to local Arduino and writes to the selected pin.
You can select
- Digital - accepts 0, 1, true, false, on, off
- Analogue (PWM) - accepts Integer 0 to 255
- Servo - accepts Integer 0 - 180
Expects a numeric value in msg.payload. The pin number is set in the properties panel.
Note - some servos will not travel a full 180 degree range so may only accept 30 - 150 degrees for example.
Please use the range node to scale the input appropriately.
Example
Simple flow to blink Pin 13
[{"id":"d7663aaf.47194","type":"arduino-board","device":""},{"id":"dae8234f.2517e","type":"inject","name":"0.5s tick","topic":"","payload":"","payloadType":"date","repeat":"0.5","crontab":"","once":false,"x":150,"y":100,"z":"359a4b52.ca65b4","wires":[["56a6f8f2.a95908"]]},{"id":"2db61802.d249e8","type":"arduino out","name":"","pin":"13","state":"OUTPUT","arduino":"d7663aaf.47194","x":570.5,"y":100,"z":"359a4b52.ca65b4","wires":[]},{"id":"56a6f8f2.a95908","type":"function","name":"Toggle output on input","func":"\n// If it does exist make it the inverse of what it was or else initialise it to false\n// (context variables persist between calls to the function)\ncontext.level = !context.level || false;\n\n// set the payload to the level and return\nmsg.payload = context.level;\nreturn msg;","outputs":1,"noerr":0,"x":358,"y":100,"z":"359a4b52.ca65b4","wires":[["2db61802.d249e8"]]}]