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CHALLENGE: Dirty Video Mixer with Sound Sensor! Answered

Hey guys

I have a challenge for you all but forewarning I am a bit of a novice with Arduino and electronics in general. I want to adapt Karl Klomp's Dirty & Cheap video mixer (schematic attached) into something a bit more responsive. The original video mixer is essentially just two RCA inputs fed into a potentiometer and then a combined output is produced as a mix of the two original video sources.

I want to swap the potentiometer for a sound sensor (image attached) to allow for the mix of the video output to be governed by the volume of the mixer's surroundings.

If anyone could please help me that would be great!!! (Even my lecturers are stumped)

Thanks in advance guys!


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7 years ago

Hmm, no matter the approach it kinda kills the simplicity of the original... Also, we don't know the output of the sound sensor--digital or analog?

If analog, it might work to use two LDRs (light-dependent resistors) to build a functional POT. But the resistance of LDRs is never zero, so there would be some signal loss. That could spronk up a video signal. There are LDRs with a range of around 400 to 10000 ohms, and it's always possible to reduce the resistance of a POT (or an LDR) by adding a parallel resistor.

Of course you'd need ,more analog circuitry (opamps) to interface the sound sensor with a couple LEDs (light sources for the LDRs).

A digital approach would be the most straight forward (not really, compared to the original curcuit), but you'd need a microcontroller board. The functional kernel (replacement of the POT) of a digital solution would be a digital potentiometer. An Arduino board would work nicely for the controller. Your sensor even looks arduino compatible. The sound sensor would interface to the micro controller, and that would control the digital POT.