Recitation 10 – Connor S.

I believe Young did a great job in his workshop on serial communication explaining how to send multiple values from Arduino to Processing. I learned that the process is fairly simple in that it requires fairly little on the Arduino side, and is relatively easy to grasp after taking some time to become acquainted with the format. 

The examples given explaining how to send information from Arduino to Processing and vice versa were helpful in understanding the relationship between the two programs and how they communicate with each other. I especially enjoyed learning more about sending multiple values from Arduino to Processing because I could see myself using this feature in future projects involving physical interactions.      

Arduino code from example:

// For sending multiple values from Arduino to Processing

void setup() {
Serial.begin(9600);
}

void loop() {
int sensor1 = analogRead(A0);
int sensor2 = analogRead(A1);
int sensor3 = analogRead(A2);

// keep this format
Serial.print(sensor1);
Serial.print(“,”); // put comma between sensor values
Serial.print(sensor2);
Serial.print(“,”);
Serial.print(sensor3);
Serial.println(); // add linefeed after sending the last sensor value

// too fast communication might cause some latency in Processing
// this delay resolves the issue.
delay(100);
}

Processing code from example:

import processing.serial.*;

String myString = null;
Serial myPort;

int NUM_OF_VALUES = 3; /** MUST CHANGE THIS **/
int[] sensorValues; /** this array stores values from Arduino **/

void setup() {
size(500, 500);
background(0);
setupSerial();
}

void draw() {
updateSerial();
printArray(sensorValues);

// use the values like this!
// sensorValues[0], sensorValues[1], …
}

// never touch below here
void setupSerial() {
printArray(Serial.list());
myPort = new Serial(this, Serial.list()[ PORT_INDEX ], 9600);
// WARNING!
// You will definitely get an error here.
// Change the PORT_INDEX to 0 and try running it again.
// And then, check the list of the ports,
// find the port “/dev/cu.usbmodem—-” or “/dev/tty.usbmodem—-”
// and replace PORT_INDEX above with the index number of the port.

myPort.clear();
// Throw out the first reading,
// in case we started reading in the middle of a string from the sender.
myString = myPort.readStringUntil( 10 ); // 10 = ‘\n’ Linefeed in ASCII
myString = null;

sensorValues = new int[NUM_OF_VALUES];
}

void updateSerial() {
while (myPort.available() > 0) {
myString = myPort.readStringUntil( 10 ); // 10 = ‘\n’ Linefeed in ASCII
if (myString != null) {
String[] serialInArray = split(trim(myString), “,”);
if (serialInArray.length == NUM_OF_VALUES) {
for (int i=0; i<serialInArray.length; i++) {
sensorValues[i] = int(serialInArray[i]);
}
}
}
}
}

Leave a Reply