Arduino data to R

serialinput.R

library(serial)

rm(list = ls())         # clear environment
graphics.off()          # close all graphic windows



### establish a serial connection

con <- serialConnection(name = "get_temps",
                        port = "COM5",
                        mode = "115200,n,8,1",
                        buffering = "none",
                        newline = 1,
                        translation = "cr")



#close(con)
isOpen(con)
open(con)
isOpen(con)



### grab data from serial port
read.serialConnection(con)

#Grab last five characters and turn into number
substrRight <- function(x, n){ substr(x, nchar(x)-n+1, nchar(x)) }

tmp <- read.serialConnection(con)
tmp
substrRight(tmp,5)
as.numeric(substrRight(tmp,5))

as.numeric(substrRight(read.serialConnection(con),5))




####  Single Non-Moving Plot

x11()

N <- 1000
x <- rep(NA,N)

for(i in seq(N)) {
  Sys.sleep(0.101)
  
  tmp <- read.serialConnection(con)
  x[i] <- as.numeric(substrRight(tmp,5))
  plot(1:N, x, type="l", ylim=c(22, 28),lwd=2,
       main="Temperature from Arduino", xlab="Seconds*10", 
       ylab="Temperature - Celsius")
}




#### Scrolling Plot

x11()
N <- 1000
x <- rep(NA,N)

for(i in seq(N)) {
  Sys.sleep(0.101)
  
  tmp <- read.serialConnection(con)
  x[i] <- as.numeric(substrRight(tmp,5))
  
  if(i<=200){
    plot(1:200, x[1:200], type="l", ylim=c(22, 28),lwd=2,
         main="Temperature from Arduino", xlab="Seconds*10", 
         ylab="Temperature - Celsius")
  } else
    
    if(i>200){
      plot((i-200):i, x[(i-200):i], type="l", ylim=c(22, 28),lwd=2,
           main="Temperature from Arduino", xlab="Seconds*10", 
           ylab="Temperature - Celsius")
    } 
  
  
}

temp1.txt

/*     ---------------------------------------------------------
 *     |  Arduino Experimentation Kit Example Code             |
 *     |  CIRC-10 .: Temperature :. (TMP36 Temperature Sensor) |
 *     ---------------------------------------------------------
 *   
 *  A simple program to output the current temperature to the IDE's debug window 
 * 
 *  For more details on this circuit: http://tinyurl.com/c89tvd 
 */
//TMP36 Pin Variables
int temperaturePin = 0; //the analog pin the TMP36's Vout (sense) pin is connected to
                        //the resolution is 10 mV / degree centigrade 
                        //(500 mV offset) to make negative temperatures an option

/*
 * setup() - this function runs once when you turn your Arduino on
 * We initialize the serial connection with the computer
 */
void setup()
{
  Serial.begin(115200);  //Start the serial connection with the copmuter
                       //to view the result open the serial monitor 
                       //last button beneath the file bar (looks like a box with an antenae)
}
 
void loop()                     // run over and over again
{
 float temperature = getVoltage(temperaturePin);  //getting the voltage reading from the temperature sensor
 temperature = (temperature - .5) * 100;          //converting from 10 mv per degree wit 500 mV offset
                                                  //to degrees ((volatge - 500mV) times 100)
 Serial.println(temperature);                     //printing the result
 delay(100);                                     //waiting a tenth of a second
}

/*
 * getVoltage() - returns the voltage on the analog input defined by
 * pin
 */
float getVoltage(int pin){
 return (analogRead(pin) * .004882814); //converting from a 0 to 1023 digital range
                                        // to 0 to 5 volts (each 1 reading equals ~ 5 millivolts
}

Great code, works great for acquisition of the data. But my plot is just empty!