Hello! I'm new to Processing, and am making an installation project based on Muybridge image sequences. I want to capture images of people jumping, and play the images back randomly in a grid. I have the basic code and steps outlined, I'm just not sure what the missing pieces are.

Steps:
-capture (saveFrame) is supposed to be set off by a tilt switch (Arduino)
-saved frames sent with naming convention to a folder called jump (would overwrite after 500 images)
-images are called back into a grid of 10 x 10 images. This is to display the jump states of various people together in a grid

My questions are:
- if it's possible to capture as well as call back images to display at the same time. I tried with a second camera.
- how to capture images at 640 x 480 and resize to the grid of 10 x 10 (64 x 48)

I'll copy both the code for the image capture/ serial event and the image grid below. Any help would be really appreciated. Thanks in advance.

GRID:
import processing.video.*; // video library

int maxImages = 16; // Total # of images (will be more)
int imageIndex = 0; // Initial image to be displayed is the first

// Declaring an array of images.
PImage[] images = new PImage[maxImages];
ImageGrid grid;

void setup() {
  size(640, 480, P2D);
  for (int i = 0; i < images.length; i ++ ) {
    images[i] = loadImage("jump" + nf(i,3) + ".jpg" );  
  }
  frameRate(5);
  grid = new ImageGrid(images,10,10);
}

void draw() {
 
  background(0);
  grid.draw(imageIndex);
 
  // increment image index by one each cycle
  // use modulo " % "to return to 0 once the end of the array is reached
  imageIndex = (imageIndex + 1) % images.length;
}

class ImageGrid {
  int xSize;
  int ySize;
  int xTiles;
  int yTiles;
  int xTile;
  int yTile;
  int xImagePos;
  int yImagePos;
  int offset;
  PImage[] images;
  int imageCount;

  ImageGrid(PImage[] tempImages, int tempXtiles, int tempYtiles) {
    images = tempImages;
    xTiles = tempXtiles;
    yTiles = tempYtiles;
  }
 
  void draw(int startOffset) {
  // get the image size
    xSize = images[0].width;
    ySize = images[0].height;
    imageCount = 0;
    for (yTile = 0; yTile < yTiles; yTile++) {
      for (xTile = 0; xTile < xTiles; xTile++) {
        xImagePos = xTile * (xSize+10) + 10;
        yImagePos = yTile * (ySize+10) + 10;
        offset = (startOffset + imageCount) % images.length;
        image(images[offset],xImagePos,yImagePos);
        imageCount++;
      }
    }
  }
}

CAPTURE/ SERIAL EVENT

import processing.video.*;
import processing.serial.*;

Serial myPort;       
Capture myCapture;

int jumpThreshold; 

void setup()
{
  size(640, 480);
myCapture = new Capture(this, width, height, 30);

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

void captureEvent(Capture myCapture) {
  myCapture.read();
 
 }

void serialEvent(Serial myPort) {
int inByte = myPort.read();
println(inByte);
jumpThreshold=inByte;
if (jumpThreshold > 0);
saveFrame("jump/jump###.jpg");
}
}