Page 344 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

Chapter 10 Projects 321

photo_right = analogRead(3);
Serial.print("right");
Serial.println(photo_right);

delay(1000); //give me time to read them in the monitor
//before drawing, check our totalHeight and totalWidth
Serial.print("totalHeight:");
Serial.println(totalHeight);
Serial.print("totaWidth:");
Serial.println(totalWidth);

delay(1000); //give me time to read them in the monitor
//store photocell values in an array
int photoValues[]= {photo_up, photo_down, photo_left, photo_right};
lowest = 9999; //set this higher than possible photocell values

//loop to find lowest photocell value
for(i = 0;i<4; i++) //4 = number of sensors
{
Serial.println(photoValues[i]); //prints out photoValue array
//assign actual photocell value to "lowest" variable if it's lower
//than whatever "lowest" is set to (starts at 9999)
if (lowest >= photoValues[i] )
{
lowest = photoValues[i];
}

//print it out to confirm that the lowest value is being selected
Serial.print("lowest:");
Serial.println(lowest);
delay(1000); //wait one second before looping so we can read the values

}//end for
distance = lowest; //set travel distance = lowest value

//if lowest value indicates a covered photocell, draw towards lowest
if (lowest < 550 )
{
//find the sensor that matched the lowest, go that direction,
//but only if SADbot is within the bounds of the canvas
if ((lowest == photoValues[0]) && ((totalHeight + distance) <
CANVASHEIGHT))