MAE 221/224 Lab Stuff

arduino_listener.ino

void setup(){
  Serial.begin(57600);
  millis();
  //analogReference(DEFAULT);
}

float vals[6];

void RMSAveraged(int time){
  float n=0;
  for(int i=0;i<6;i++) vals[i]=0;
  int sleep = ceil(float(time)/50);
  for(int t=0;t<sleep;t++){
    n++;
    for(int i=0;i<6;i++){
      vals[i]=vals[i]+sq(analogRead(i)/1023.0*5);
    }
    delay(50);
  }
  if(n>0){
    for(int i=0;i<6;i++){
      vals[i]=sqrt(vals[i]/n);
    }
  }
}

void rawRead(){
  for(int i=0;i<6;i++){
    vals[i]=analogRead(i)/1023.0*5;
  }
}

void voltsToJSON(){
  RMSAveraged(1000);
  //rawRead();

  Serial.print("{\"A0\":");
  Serial.print(((vals[0])));

  Serial.print(",\"A1\":");
  Serial.print(((vals[1])));

  Serial.print(",\"A2\":");
  Serial.print(((vals[2])));

  Serial.print(",\"A3\":");
  Serial.print(((vals[3])));

  Serial.print(",\"A4\":");
  Serial.print(((vals[4])));

  Serial.print(",\"A5\":");
  Serial.print(((vals[5])));

  Serial.print("}");
  Serial.println("");
}

void loop(){
  if(Serial.available()>0){
    Serial.flush();
    //voltsToJSON();
  }
  voltsToJSON();
  //delay(500);
}

nodeforwarder.js

/* 
NodeForwader: an serial to http proxy driven by ghetto get calls
requirements 
   -- serialport -> npm install serialport
   -- express -> npm install express
   -- sleep -> npm install sleep

to start: node nodeforwader.js [HTTP PORT] [SERIAL PORT] [BAUD] [BUFFER LENGTH]
to read: http://[yourip]:[spec'd port]/read/  -> returns the last [BUFFER LENGTH] bytes from the serial port as a string
to write: http://[yourip]:[spec'd port]/write/[YOUR STRING HERE]

what will probably create farts/list of things to deal with later if I need to:
- returning characters that html has issues with
- spaces in the url

*/

parts = process.argv

if (parts.length < 6)
{
  console.log("usage: node nodeforwader.js [HTTP PORT] [SERIAL PORT] [BAUD] [BUFFER LENGTH]")
	process.exit(1);
}

else
{
	console.log(parts);
	hp = parts[2]
	sp = parts[3]
	baud = parseInt(parts[4])
	blen = parseInt(parts[5])
}

var express = require('express');
var app = express();

app.listen(hp);

var sleep = require("sleep").sleep
var SerialPort = require("serialport").SerialPort ;
var serialPort = new SerialPort(
	sp, 
	{
		baudrate: baud		
	}
);

serialPort.on("open", function () { 
	console.log('open');
    
});  

//sleep for 5 seconds for arduino serialport purposes
for (var i=0; i<5; i++ )
{
	console.log(i);
	sleep(1); 
}


//On Data fill a circular buf of the specified length
buf = ""
serialPort.on('data', function(data) {
   buf += data	   
   if (buf.length > blen) buf = buf.substr(buf.length-blen,buf.length) 
   
});

//Write to serial port
app.get('/write/*',function(req,res){	
	toSend = req.originalUrl.replace("/write/","")
	toSend = decodeURIComponent(toSend);
	serialPort.write(toSend)
	res.send(toSend)
});

//read buffer
app.get('/read/', function(req, res){
	res.send(buf)
});