====== Configuration of the Device ======
The device is configured by careful selection of **R1** and **R2**.  The formula used to select the resistors is:

  vTrigger ≈ 2.6 × ( 1 + ( R1 / R2 ) )
  
For example, using an **R1** of 3.9K and an **R2** of 3.3K yields a trigger voltage of about 5.67v:

  vTrigger ≈ 2.6 × ( 1 + ( 3.9 / 3.3 ) ) ≈ 5.67272727
  
Another way to calculate the resistors is starting with a known //vTrigger// and **R1** values in order to calculate **R2**:

  ( ( R1 * vTrigger ) / 2.6 ) - R1 ≈ R2

For example, I want a //vTrigger// of 7v and I want an **R2** to be a 3.3K resistor:

  ( ( 3.3 * 7.0 ) / 2.6 ) - 3.3 ≈ 5.58

So my **R1** should be 5.58K.  Now, it might be hard to find a 5.58K resistor but you at least know the neighborhood you need to be in.  It is also important to remember that when you do select your resistor, remember that its tolerance plays a part in determining the actual trigger voltage.  So you might not hit exactly on the calculated voltage.

Another way to wire the board for greater flexibility is to use 3.3K resistors for both **R1** and **R2** but wire **R1** inline with a 10k or 20k pot.  Combined with an adjustable power supply, you should be able to dial in a desired //vTrigger// easily.

Lastly, note that I am //quite// bad with math, so double-check any values you get from this second formula calculation against the first one.