Project Development

I lost some a lot of time backtracking to figure out how the system should move. During that time the class gave some great feedback regarding the interaction of the control station. The explicate interactions of the control station didn’t really make sense in this context, rather using implied or indirect interactions may be better. I decide to incorporate this feedback into the project and will have two variables for each axis, speed and distance. Sensors will provide the data to be used for each of the variables. I’m currently working with an Adafruit VL53L0X Time-of-flight sensor and a Pololu Tic T834 stepper driver to work out the code for the movement. I’m implementing smoothing on the raw data provided by the VL53L0X in order to provide a more stable set of movement instructions to the motor driver. Below is the current code that I’m working on.

/*
  Smoothing

  Reads repeatedly from an analog input, calculating a running average and
  printing it to the computer. Keeps ten readings in an array and continually
  averages them.

  The circuit:
  - analog sensor (potentiometer will do) attached to analog input 0

  created 22 Apr 2007
  by David A. Mellis  <dam@mellis.org>
  modified 9 Apr 2012
  by Tom Igoe

  This example code is in the public domain.

  http://www.arduino.cc/en/Tutorial/Smoothing
*/

// Define the number of samples to keep track of. The higher the number, the
// more the readings will be smoothed, but the slower the output will respond to
// the input. Using a constant rather than a normal variable lets us use this
// value to determine the size of the readings array.
#include "Adafruit_VL53L0X.h"

Adafruit_VL53L0X lox = Adafruit_VL53L0X();
unsigned long startMillis;
unsigned long currentMillis;
const unsigned long period = 4000;
const int numReadings = 10;

int readings[numReadings];      // the readings from the analog input
int readIndex = 0;              // the index of the current reading
int total = 0;                  // the running total
int average = 0;                // the average

int distance = 0;
//int inputPin = A4;

void setup() {
  // initialize serial communication with computer:
  Serial.begin(115200);

  // initialize all the readings to 0:
  for (int thisReading = 0; thisReading < numReadings; thisReading++) {
    readings[thisReading] = 0;
  }

  // wait until serial port opens for native USB devices
  while (! Serial) {
    delay(1);
  }

  Serial.println("Adafruit VL53L0X test");
  if (!lox.begin()) {
    Serial.println(F("Failed to boot VL53L0X"));
    while (1);
  }
  // power
  Serial.println(F("VL53L0X API Simple Ranging example\n\n"));
  startMillis = millis();  //initial start time
}

void loop() {
  currentMillis = millis();

  VL53L0X_RangingMeasurementData_t measure;
  distance = measure.RangeMilliMeter;

  
  lox.rangingTest(&measure, false); // pass in 'true' to get debug data printout!
  delay(100);

  // subtract the last reading:
  total = total - readings[readIndex];
  // read from the sensor:
  //  readings[readIndex] = analogRead(inputPin);
  readings[readIndex] = distance;
  // add the reading to the total:
  total = total + readings[readIndex];
  // advance to the next position in the array:
  readIndex = readIndex + 1;

  // if we're at the end of the array...
  if (readIndex >= numReadings) {
    // ...wrap around to the beginning:
    readIndex = 0;
  }

  // calculate the average:
  average = total / numReadings;
  int  steps = map(average, 0, 9000, -400, 400);
  // send it to the computer as ASCII digits
  Serial.print("Distance"); Serial.println(distance);
  Serial.print("Average"); Serial.println(average);

  if (currentMillis - startMillis <= period) {
    analogWrite(A0, steps);
    //  delay(5000);        // delay in between reads for stability
  }
  startMillis = currentMillis;
}

The other big change that I haven’t mention yet is the way the RGB LED will react to the movements. Originally the LED just cycled through the RGB spectrum, again this felt a bit disconnected to the overall theme and even the mechanical process by which the images outputs were made. At this point the plan is to use the X/Y location of the carriage to change the HSL value of the RGB LED. This should produce fairly chaotic results even though the carriage position will always produce the same RGB value the position of the pendulum will very rarely be directly under the carriage. So the colors in the image output will never be in the same location.

I’ve made good headway in fully conceptualizing the installation in what could be the final form but there is still a long way to go for realization.