I've tweaked the code on the thermal flashlight a bit. In our testing, we were getting red for hot, but blue-green for cold (and figured 'blue' should be for the cold).

Here is a reference on how the color HSV (hue, saturation and value) converts to RGB:

http://en.wikipedia.org/wiki/HSV_color_space

Figure 24 shows the essence of what we are trying to do; 0 degrees = red; 240 degrees = blue.

The code in the sketch is almost correct; originally, the value was 360*0.6 = 216 degrees for the coldest value, which is blue-green. 240 degrees gives you blue, so you have:

// Regular ol' RGB LED: // original //int hue = map(state,0,255,(360.00*0.60),0); // not the whole color wheel // // 0 degrees is red, 240 degrees is blue // See http://en.wikipedia.org/wiki/HSV_color_space // Figure 24. // 0=cold is 240 degrees (blue) // 255=hot is 0 degrees (red) int hue = map(state,0,255,240,0);

setLedColorHSV(hue,1,1); //We are using Saturation and Value constant at 1

The other part of the code that will have to change is that if you use a common anode RGB LED (the LED from RadioShack is 276-0028 (common anode (+), which is at 5V), when the PWM output is at 255 for a particular color (5V is on all the time), that color in the LED will be off. So we have to invert the output (zero becomes 255, 255 becomes zero):

// Since we are using common anode, when value is 255 (on always) // the LED for that element is OFF, so, make a swap setLedColor(255-red,255-green,255-blue);