arduino-nodejs

Module for arduino-nodejs communication

const arduino_node = require("arduino-nodejs")

// Returns a promise
// Example of result: ["COM9", "COM3", "COM1"]
// The lower on the list, the bigger is the chance
// Of it being a arduino board
arduino_node.list()

// COM_port should be a port returned by list()
// Baud_rate should be one of the rates
// Here: https://arduino.stackexchange.com/questions/296/
// Baud rates higher than 115200 may not work on
// Devices using CH430G/CH430 or other non-standard
// USB to Serial converters

// Delay should be a number in milliseconds to wait
// After sending a message.
// With lower baud rates it may be neccesary to include
// A number bigger than 10
arduino_node.connect(COM_port, Baud_Rate, Delay?)

// Sends a object to the Arduino
await arduino_node.write(object)

// Reads a value. Should be in a interval
// As small as possible to get the 
// information fast
arduino_node.read()

// The arduino code should be like this:

#include <ArduinoJson.h>


void setup()
{
  Serial.begin(115200); // Should be the same baud rate as using in the nodejs file
}

void loop()
{
  if (Serial.available()) {
    DynamicJsonDocument doc(1024);
    deserializeJson(doc, Serial);

    if (doc["fingerprint"] == "X-Node-Fingerprint") {
      // Arduino detected the serial write and that it is from a nodejs script
      // Do something cool here

    }
  }
}

// Example of code that displays the views and likes of a youtube video:

// NodeJS 

await arduino_node.connect(list[0], 115200, 10)

const arduino_node = require("arduino-nodejs")
const gaxios = require("gaxios")
let video_id = "aKkVqmvs4NA"
let youtube_key = ""
let link = `https://www.googleapis.com/youtube/v3/videos?part=statistics&id=${id}&key=${youtube_key}`

function scrapeData(id) {
    return new Promise((resolve, reject) => {
        gaxios.request({ method: "GET", url: link})
            .then((data) => {
                resolve(data.data.items[0].statistics)
            })
            .catch((err) => {
                reject(err)
            })
    })
}

function printToScreen(){
    scrapeData(video_id)
    .then(async (data) => {
        await arduino_node.write({ type: "lcd_clear" })
        await arduino_node.write({ type: "setCursor", "pos1": 0, "pos2": 0 })
        await arduino_node.write({ type: "lcd_print", "text": `views: ${data.viewCount}` })
        await arduino_node.write({ type: "setCursor", "pos1": 0, "pos2": 1 })
        await arduino_node.write({ type: "lcd_print", "text": `likes: ${data.likeCount}` })
    })
}


arduino_node.list().then(async (list) => {
    arduino_node.connect(list[0], 115200, 10)

    printToScreen()
    setInterval(async () => {
        printToScreen()
    }, 8100);
}).catch((err) => {
    console.log(err)
})

// Arduino

#include <LiquidCrystal_I2C.h>
#include <ArduinoJson.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); // This is using the I2C version, change this if you want the normal one

void setup()
{
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
}

void loop()
{
  if (Serial.available()) {
    DynamicJsonDocument doc(1024);
    deserializeJson(doc, Serial);

    if (doc["fingerprint"] == "X-Node-Fingerprint") {
      if (doc["type"] == "lcd_print") {
        lcd.print(doc["text"].as<String>());
      } else if (doc["type"] == "lcd_clear") {
        lcd.clear();
      } else if (doc["type"] == "setCursor") {
        lcd.setCursor(doc["pos1"].as<int>(), doc["pos2"].as<int>());
      }
    }
  }
}