Arduino EMI shield

So a while ago I answered a question on Arduino.SE with regards to a person wanting to shield there Arduino from EMI( Electromagnetic Interference) that was coming from some AC they were feeding into a shield on the Arduino, and thus they asked if it would be plausible to use a shield in between the Arduino and the other device to stop interference. Thus I brought out some points to help that person.

Some things I answered in it:

• Using DC Ground
• Using AC Earth/Ground
• Isolating circuitry 
• Extra, PCB layout

Sound sensor with Arduino, freeform

 

I was in need of a sound sensor board because I wanted to test some code that someone was experiencing issues with, so I scrounged around for some scrap parts and decided to make a free form circuit of the common sound sensor circuit, I used this as a base:

I made some modifications for the look of it, such as the ceramic caps and not the electrolytic ones.

The modification I made to the circuit was the addition of a comparator using the free half of the LM358. That is what the green trim pot is for at the top of the circuit.

I used enamel coated wire from a stripped transformer. The other parts were from various PCBs I have collected... Hackaday calls it Fracking.

 

 That seems to be about all the photos I took. But the idea is simple in that you take the wire and bend it around a cylindrical shape of your choice and arrange the curves to the way in which it best fits. 

I ran two lines straight down the centre to get Positive and Ground along the sides where the OP-AMP power pins are. Also I ran the output from the final stage down the side too. Any other connections were made however they best fitted into the arrangement.