Processing+Arduino+DistanceSensor

jobomb

Processing+Arduino+DistanceSensor

in Integration and Hardware • 1 year ago

Trying to figure out how to code in processing to read values from my distance sensor (HC-SR04) and have the values change an image on the screen. Ideally I'd like to be able to change the brightness of an image, and eventually be able to change frames in a short animation using the distance sensor.

I've followed this tutorial on youtube http://www.youtube.com/watch?v=g0pSfyXOXj8 which teaches how to use a potentiometer to change the brightness of a drawn rectangle, but I couldn't figure out how to replace the potentiometer with the distance sensor.

Any ideas?

Here's the code I used for both the arduino and processing.

Any help is much appreciated!

Arduino code:

#include "Ultrasonic.h"

int TRIG = 2; // Trigger Pin
int ECHO = 3; // Echo Pin
int Range; // The range of the object from the HC-SR04 Ultarsonic Module

Ultrasonic ultrasonic(TRIG,ECHO); // Create and initialize the Ultrasonic object.

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

void loop() {

Range = ultrasonic.Ranging(CM); // Range is calculated in Centimeters.
// Range = ultrasonic.Ranging(INC); // Range is calculated in Inches.

int val = map(analogRead(Range), 0, 1023, 0, 255);

Serial.print(Range);
Serial.println("CM");
Serial.println(val);
delay(50);

}

Processing Code:

import processing.serial.*;
Serial port;
float brightness = 0;

void setup()
{
size (500,500);
port = new Serial(this, "/dev/tty.usbmodem1d11", 9600);
port.bufferUntil('\n');
}
void draw()
{
background(0,0,brightness);
}

void serialEvent (Serial Port)
{
brightness = float(port.readStringUntil('\n'));
}

Replies(14)

Jesse Sco..

Re: Processing+Arduino+DistanceSensor

1 year ago

That seems like it will work...

One thing is that you are sending an Integer and trying to receive it as a Float, but that's possible to do if you cast it correctly...

But, you are sending the range variable, not the mapped val variable... so either send the val or map it again in Processing...

jobomb

Re: Re: Processing+Arduino+DistanceSensor

1 year ago

Thanks,

Im pretty new to programming so you haveto be a bit more specific as to what you said to do here "...so either send the val or map it again in Processing..."

I'm still learning so I don't quite understand everything in the code, I just copied and pasted it from the tutorials so I'm having a bit of trouble getting it to work.

I tried another arduino code for the distance sensor and I seem to be getting feedback through processing, but no matter what values i put in the map, i get the same results... The image also flashes a lot, which i'm guessing is do to the noise being picked up by the sensor...

anyways here's the code for arduino im trying now...

double ping(int outPin, int inPin) //Get CM to obstacle in front of the sensor
{
long duration;
pinMode(outPin, OUTPUT);
pinMode(inPin, INPUT);
digitalWrite(outPin, LOW);
delayMicroseconds(2);
digitalWrite(outPin, HIGH);
delayMicroseconds(15);
digitalWrite(outPin, LOW);
delayMicroseconds(20);
duration = pulseIn(inPin, HIGH);
return duration / 29.0 / 2.0;
}

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

void loop()
{
int val = map(ping(2, 3), 40, 200, 0, 255);       // for the values here I am using 40 (cm) as my minimum
Serial.println(ping(2, 3));                                    and 200 (cm) as my maximum distance...
delay(50);
}

I have a feeling that for the map values i'm not supposed to use the distance in "cm" but probably the readings from the sensor before being converted to "cm" , so i tried to get those values and serialPrintln them and i got some really long numbers in the thousands, and i tried them as the map values but the result was no different as before.... which is the image brightness not going black until im a couple cm away from the sensor (practically touching it)

Thanks again for the help! I really appreciate it!

jobomb

Re: Processing+Arduino+DistanceSensor

1 year ago

any suggestions?

bngllghr

Re: Processing+Arduino+DistanceSensor

1 year ago

Hi Jobomb,

I'm looking at something similar myself, but haven't quite cracked it yet. Also, I'm using a 3pin sensor, so my code differs a bit from yours. But, one thing I see from your code is that you map your sensor input to a variable called val but you don't print the new mapped value. Instead you are printing the raw data from the sensor (which is the number of microseconds that it takes for the ultrasonic signal to return). This likely explains the large numbers you're getting.

Try Serial.println(val); // print the mapped value (See if you get anything in the serial monitor).

Also, you can't use analogueRead on a digital pin (your first Arduino code).

The other thing I noticed in your Processing code was that you haven't set the colour mode to HSB (hue, saturation, brightness). Processing, by default, uses RGB. So the third parameter you are controlling (brightness) is currently changing the blue value of your background, rather than the brightness.

I hope this at least helps to point you in the right direction. I'm not entirely certain of the fix yet, but will post back if I sort it. Unless, someone more experienced comes along;)

jobomb

Re: Re: Processing+Arduino+DistanceSensor

1 year ago

Thank you, that makes sense... and yeah I did it using RGB because I was following a tutorial that did it that way... just trying to figure it out this way, then hopefully I'll be able to figure out how to change brightness of an image I upload.

And please comment back if you figure it out! and I will do the same.

Thanks again for the heads up!

bngllghr

Re: Processing+Arduino+DistanceSensor

1 year ago

Here's my code as it stands, in case it helps. I've got it mapped to 0-255, but need to look more at data types to know how to get it into processing correctly. Hope to find time to do this in the next couple of days. I've taken the distance stuff out of the ping example because I don't need it, but you should be able to see where it goes by looking at the original. For 3 pin ultrasonic.

// Adapted from: http://www.arduino.cc/en/Tutorial/Ping
// this constant won't change. It's the pin number
// of the sensor's output:
const int pingPin = 7;
void setup() {
// initialize serial communication:
Serial.begin(9600);
}
void loop()
{
// establish variables for duration of the ping
long duration;
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);
// The same pin is used to read the signal from the PING))): a HIGH
// pulse whose duration is the time (in microseconds) from the sending
// of the ping to the reception of its echo off of an object.
pinMode(pingPin, INPUT);
duration = pulseIn(pingPin, HIGH); // Read pulse length and store it in 'duration'
duration = constrain(duration, 1000, 20000); // Ignore values outside 1000 & 20000 //microseconds
int val = map(duration, 1000, 20000, 0, 255); // Map duration to the range 0 - 255 (consider data //type!)
Serial.println(val); // Print the value within the new range
delay(100);
}

jobomb

Re: Processing+Arduino+DistanceSensor

1 year ago

any luck?

bngllghr

Re: Processing+Arduino+DistanceSensor

1 year ago

Not really. Spent quite some time on it today, but am struggling. Bytes printing ok to arduino monitor, but processsing isn't picking them up.

bngllghr

Re: Processing+Arduino+DistanceSensor

1 year ago

Ok, got it. Finally. You'll need to adapt this for your 4pin, and if you need cm's etc, but this works.

Arduino code:

const int pingPin = 7;
void setup() {
// initialize serial communication:
Serial.begin(9600);
}
void loop()
{
// establish variables for duration of the ping
int duration;
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);
// The same pin is used to read the signal from the PING))): a HIGH
// pulse whose duration is the time (in microseconds) from the sending
// of the ping to the reception of its echo off of an object.
pinMode(pingPin, INPUT);
duration = pulseIn(pingPin, HIGH); // Read pulse length and store it in 'duration'
int val = map(duration, 1000, 5000, 0, 255); // Map duration to the range 0 - 255
val = constrain(val, 0, 255); // Limit to desired range
Serial.print(val, BYTE); // Print as bytes
delay(5);
}

Processing code:

// Example by Tom Igoe
import processing.serial.*;
Serial myPort; // The serial port
void setup() {
// List all the available serial ports
println(Serial.list());
// I know that the first port in the serial list on my mac
// is always my Keyspan adaptor, so I open Serial.list()[0].
// Open whatever port is the one you're using.
myPort = new Serial(this, Serial.list()[0], 9600);
}
void draw() {
while (myPort.available() > 0) {
int inByte = myPort.read();
println(inByte);
background(inByte);
}
}

jobomb

Re: Processing+Arduino+DistanceSensor

1 year ago

Awesome!

Im gonna have to try this out!!!

Thanks!

jobomb

Re: Processing+Arduino+DistanceSensor

1 year ago

Great!

I tried to modify this to my 4 pin but couldn't figure it out for some reason. ANyways, I actually had a 3 pin LV MaxSonar EZ-1 sensor laying around and this code worked fine with it! jut wish the LV Maxsonar had better detection. Anyways thanks alot for the help...

Now I need to figure out how to upload an image and make that fade to black instead of a white fading to black... suggestions for that?

Update**

Ok, figured out how to control image birhgtness with the following code.

// Example by Tom Igoe

import processing.serial.*;

Serial myPort; // The serial port
PImage img;

void setup() {
// List all the available serial ports
println(Serial.list());
// I know that the first port in the serial list on my mac
// is always my Keyspan adaptor, so I open Serial.list()[0].
// Open whatever port is the one you're using.
myPort = new Serial(this, Serial.list()[0], 9600);
   size(600, 900);
img = loadImage("g.jpg");
}

void draw() {
while (myPort.available() > 0) {
    int inByte = myPort.read();
    println(inByte);
    tint(inByte);
    image(img, 0,0,width,height);

}
}

But not getting great results as far as the transition of the fading. Seems to jump alot, It could just have to do with the precision of the sensor. I tried plugging the arduino in with the wall adapter to see if it needed more power but its still not going that smooth. I think it may have something to do with the serial write speed from arduino to processing? IDK

bngllghr

Re: Processing+Arduino+DistanceSensor

1 year ago

There was a bug in my Arduino code, causing the data to jump between 0 and 255; results were inconsistent. I've put in a small delay to fix it (also taken the first constrain function out as it was inefficient). Give it a try.

I don't imagine it's too difficult to substitute for your 4 pin sensor, just get the reading (in microseconds) into duration, and then add the last few lines of my code:

1. int val = map(duration, 1000, 5000, 0, 255); // Map duration to the range 0 - 255
2. val = constrain(val, 0, 255); // Limit to desired range
3. Serial.print(val, BYTE); // Print as bytes
4. delay(5);

bngllghr

Re: Processing+Arduino+DistanceSensor

1 year ago

Also, this is smoother:

void draw() {
image(img, 0,0,width,height);
while (myPort.available() > 0) {
int inByte = myPort.read();
println(inByte);
tint(inByte);
}

jobomb

Re: Processing+Arduino+DistanceSensor

1 year ago

Thanks!

Ill test it out when i get home from work

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