does someone have working code in Processing for Serial processing from Arduino ( a line at a time )

Integration and Hardware

jdawgaz

does someone have working code in Processing for Serial processing from Arduino ( a line at a time )

in Integration and Hardware • 1 year ago

I am fairly new to Processing, so pardon the newbie question

I have an arduino program that prints out a csv string val1,val2,val3,val4\n:

int firstSensor = 0;

int secondSensor = 0;

int reset = 0;

int serve = 0;

int inByte = 0;

void setup()

{

// start serial port at 9600 bps:

Serial.begin(9600);

randomSeed(10);

//establishContact(); // send a byte to establish contact until Processing responds

}

void loop()

{

// if we get a valid byte, read analog ins:

if (Serial.available() > 0) {

inByte = Serial.read();

firstSensor = random(385);

secondSensor = random(385);

reset = random(0,2);

serve = random(0,2);

if (reset == 1) {

serve = 0;

}

Serial.print(firstSensor);

Serial.print(',');

Serial.print(secondSensor);

Serial.print(',');

Serial.print(reset);

Serial.print(',');

Serial.println(serve);

}

I can read the data in python:

#!/usr/bin/env python

import serial

from time import sleep

s = serial.Serial(port='/dev/tty.usbmodem411', baudrate=9600)

while (1):

sleep(1)

s.write('\n')

l = s.readline().strip()

print l

but I can't get this to work in Processing:

I am trying to use serialEvent and bufferUntil, but no matter what I try, absolutely nothing comes over.

Does anyone have any working code that would take the output of the arduino in processing?

thanks,

Jerry

Replies(3)

monk_of

Re: does someone have working code in Processing for Serial processing from Arduino ( a line at a time )

1 year ago

Hey!

look at this... http://wiring.org.co/learning/basics/sendingmultipledata.html , wiring/arduino has the same code.

Sending strings separated by commas and the semicolon is being used to determine end of the line.

:) hope it helps!

jdawgaz

Re: does someone have working code in Processing for Serial processing from Arduino ( a line at a time )

1 year ago

monk_of:

I copied your code and added a couple of print statements:

I also downloaded the latest 2.x beta release.

I forgot to mention that I am running this on OSX 10.7 (maybe thats the problem)

Heres your code with the mods:

(Basically, I get the "draw()" message, but not the "serialEvent(): at start" message):

Is there something else that I need to do?

Jerry

===== your code + mods =====

/**

* Data from multiple sensors / Processing

* by BARRAGAN < http://barraganstudio.com>

* based on Tom Igoe's example from Making Things Talk book

* read serial data until a linefeed character found

* data are values comma separated. Split the data and convert it

* into numbers in an array for firther use.

import processing.serial.*;

Serial myPort;

int linefeed = 10; // Linefeed in ASCII

int numSensors = 4; // we will be expecting for reading data from four sensors

int sensors[]; // array to read the 4 values

int pSensors[]; // array to store the previuos reading, usefur for comparing

// actual reading with the last one

void setup() {

size(200, 200);

// List all the available serial ports in the output pane.

// You will need to choose the port that the Wiring board is

// connected to from this list. The first port in the list is

// port #0 and the third port in the list is port #2.

println(Serial.list());

myPort = new Serial(this, Serial.list()[0], 9600);

// read bytes into a buffer until you get a linefeed (ASCII 10):

myPort.bufferUntil(linefeed);

}

void draw() {

if ((pSensors != null) && (sensors != null)) {

// if valid data arrays are not null

// compare each sensor value with the previuos reading

// to establish change

for (int i=0; i < numSensors; i++) {

float f = sensors[i] - pSensors[i]; // actual - previous value

if (f > 0) {

println("sensor "+i+" increased by "+f); // value increased

}

if (f < 0) {

println("sensor "+i+" decreased by "+f); // value decreased

}

// now do something with the values read sensors[0] .. sensors[3]

}

delay(300);

println("draw(): writing to myPort");

myPort.write(linefeed);

}

void serialEvent(Serial myPort) {

println("serialEvent(): at start");

// read the serial buffer:

String myString = myPort.readStringUntil(linefeed);

// if you got any bytes other than the linefeed:

if (myString != null) {

myString = trim(myString);

// split the string at the commas

// and convert the sections into integers:

pSensors = sensors;

sensors = int(split(myString, ','));

// print out the values you got:

for (int sensorNum = 0; sensorNum < sensors.length; sensorNum++) {

print("Sensor " + sensorNum + ": " + sensors[sensorNum] + "\t");

}

// add a linefeed after all the sensor values are printed:

println();

}

jdawgaz

Re: does someone have working code in Processing for Serial processing from Arduino ( a line at a time )

1 year ago

I tried something a little different. I started the arduino as usual.

I could run my python program, and it worked beautifully, but couldn't get anything to work in Processing.

What I did, was:

1. run arduino program

2. this time I ran the python program.

3. run Processing sketch (it was stopped -- no input as before)

4. stop the python program

Processing keeps on running great.

After running the python program (for just a little bit), the Processing sketch worked as designed (getting data).

So I am thinking its the way Processing is setting up the Serial port (at least on osx).

I started stepping through code in my python program and here is what I have found:

bytesize=8,

parity='N',

stopbits=1,

timeout=None,

xonxoff=False,

rtscts=False,

dsrdtr=False

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