March Madness Challenge - Day 22

Thought about what I was going to do, figured it would be some twist yesterday, and lo it was. Based on some sample code, and mixing it with simplejson I'm loading json data from the Arduino over serail and transforming it into a Python dictionary. This is neat for few things. One is that is formatted to be Python friendly or anything that reads JSON. it can easily be hooked up to something like a web framework like Django, Pylons, etc. I'll show the test Python code and then the updated Arduino code.

Python

import serial
import simplejson as json

ser = serial.Serial('/dev/tty.usbserial-A7004qpc',19200)
while 1:
 try:
  entry = json.loads(ser.readline())
  print entry
  print entry[u'entry'].keys()
 except KeyboardInterrupt:
         raise
 except:
  print "value not json"

Arduino RGB Calibration JSON code

/*
* The RGB Calibrator
* 
* Find, and monitor max brightness of red, green, and blue in an RGB led
*/


int redPin = 9;    // LED connected to digital pin 9
int greenPin = 11;
int bluePin = 10;
int pins[] = 
{
    redPin, greenPin, bluePin
};
int i =0;

int photoPin = 0;
int potPin = 1;

int photoVal = -1;
int r,g,b = -1;
int rmax, gmax, bmax = 0;
int rmin, gmin, bmin = 1024;

long interval = 500; 
long previousMillis = 0;

void setup()  
{ 
  Serial.begin(19200);
 // Serial.println("Setup done");
  
  pinMode(redPin, OUTPUT);     
  pinMode(greenPin, OUTPUT);     
  pinMode(bluePin, OUTPUT);  
  digitalWrite(redPin, HIGH);
  digitalWrite(greenPin, HIGH);
  digitalWrite(bluePin, HIGH); 

  digitalWrite(redPin, LOW);
  delay(1000);
  digitalWrite(redPin, HIGH);

  digitalWrite(greenPin, LOW);
  delay(1000);
  digitalWrite(greenPin, HIGH);

  digitalWrite(bluePin, LOW);
  delay(1000);
  digitalWrite(bluePin, HIGH);
  
} 


void loop()  
{
  if (i > 2) //The number of LEDS being measured
  {
     i = 0; 
  }
  
  digitalWrite(pins[i], LOW);     
  photoVal = analogRead(photoPin);
  
  
  switch (i)
  {
   case 0: //red led
     r = photoVal;
     rmin = min(rmin, r);
     rmax = max(rmax, r);
     break;
   case 1: //green led
     g = photoVal;
     gmin = min(gmin, g);
     gmax = max(gmax, g);
     break;
   case 2: //blue led
     b = photoVal;
     bmin = min(bmin, b);
     bmax = max(bmax, b);
    break;
   default: //should not happen
     break;
    
  }
  Serial.print ("{ \"entry\" :");
  Serial.print(" { \"photoVal\" : ");
  Serial.print(photoVal);
  
  Serial.print(", \"rmax\" : ");
  Serial.print(rmax);
  Serial.print(", \"gmax\" : ");
  Serial.print(gmax);
  Serial.print(", \"bmax\" : ");
  Serial.print(bmax);
  
  Serial.print(", \"rmin\" : ");
  Serial.print(rmin);
  Serial.print(", \"gmin\" : ");
  Serial.print(gmin);
  Serial.print(", \"bmin\" : ");
  Serial.print(bmin);
  
  Serial.print(", \"r\" : ");
  Serial.print(r);
  Serial.print(", \"g\" : ");
  Serial.print(g);
  Serial.print(", \"b\" : ");
  Serial.print(b);
  Serial.println("}}");
  
  if (millis() - previousMillis > interval) {
    previousMillis = millis();   
    digitalWrite(pins[i], HIGH);
    i++;    
   }
}