Can Processing Send Serial Data to Arduino if the Processing Sketch is NOT the Focus Program???

zjweaver

Can Processing Send Serial Data to Arduino if the Processing Sketch is NOT the Focus Program???

in Integration and Hardware • 1 year ago

Hi gang. The wordy title says it all. I want to be able to send serial data to Arduino (simply key stroke counting) but be able to focus on other programs on my Mac.

Is there a way for me to be typing in Word, let's say, and have Processing count my keystrokes and send that to Arduino?

Any other software for that? Doesn't have to be Processing.

Much appreciated. Cheers,

Replies(4)

deancs

Re: Can Processing Send Serial Data to Arduino if the Processing Sketch is NOT the Focus Program???

1 year ago

Hi, Processing apps run as standard Java so there is no issue sending serial data whilst your application is in the background. I can't comment on the ability get get/count key strokes from another app though.

zjweaver

Re: Re: Can Processing Send Serial Data to Arduino if the Processing Sketch is NOT the Focus Program???

1 year ago

That's exactly the issue. The app is open in processing, in the background. But as soon as you begin working in another application (thus becoming the focus), the Processing app no longer counts keystrokes. Here is the Processing side of the code if it helps:

And thank you for the reply.

//Open the Serial library

import processing.serial.*;

//give the Serial port a name

Serial myPort;

//The variable that is sent to Arduino. Byte converts an ASCII value to a corresponding

//integer that Arduino equilibrates with the variable 'Position'.

byte target;

int keyCount;

int timePassed;

boolean noActionYet;

void setup()

{

size(100,100);

keyCount = 0;

timePassed = 0;

noActionYet = true;

////Begin adapted example by Tom Igoe from Processing API reference: write()

// List all the available serial ports in the terminal window at startup.

println(Serial.list());

//The following is used to select the proper Serial port from the list generated above

myPort = new Serial(this, Serial.list()[0], 9600); //Array index [0] corresponds with the Serial port I need to use.

myPort.bufferUntil('\n');

////End adapted example by Tom Igoe from Processing API reference of write()

}

void draw()

{

activity();

}

void activity()

{

timePassed ++;

target = byte(keyCount);

if (keyPressed){

noActionYet = false;

keyCount = keyCount +1;

timePassed = 0;

}

if(timePassed > 300 && noActionYet == false){

keyCount = keyCount -10;

timePassed = 0;

}

myPort.write(keyCount);

//println(target);

}

deancs

Re: Can Processing Send Serial Data to Arduino if the Processing Sketch is NOT the Focus Program???

1 year ago

The modal basis of most (any) windowing environment is that the application with "focus" captures the keyboard. As a result this constraint exists with most programming environments. In order to achieve what you require you would require some form a low level keyboard intercepter that can read your keystrokes whilst passing them to the in focus application. As this has been the basis for all forms of hacks/viruses/snooping the OS controls around this are pretty tight. Under MSWindows and OSX this is managed by the HID (Human Interface Device) APIs. Try goggling 'keyboard listener'

zjweaver

Re: Re: Can Processing Send Serial Data to Arduino if the Processing Sketch is NOT the Focus Program???

1 year ago

deancs,

Right on! Using "keyboard listener" as a search (instead of "key logger" which has nefarious connotations) I found a free app called logKext which runs via Terminal in Mac and the directory can be accessed via Processing using BufferReader library which in turn is set to send serial to Arduino as long as the sketch is running.

Thank you for the clue.

zjw

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