This is an electronic input switcher for amateur DJ’s who are running short on inputs on the audio mixer.
It allows you to connect 2 inputs to channel 1 and 2 each, and 3 inputs to channel 3.
Each input channel has a toggle switch and 2 or 3 LEDs indicating the active input. The actual switching is done using DPDT relays driven by Arduino (AT328p) via a simple 2N222A or even BD547 NPN transistor. It also has a potentiometer in A0, which drives a BD139 NPN Darlington transistor using PWM, allowing you to regulate the brightness of an LED strip that illuminates the mix table.
Button 1 switches between inputs 1 and 2 on channel “A” (and lights up the corresponding LED)
Button 2 switches between inputs 3 and 4 on channel “B” (and lights up the corresponding LED)
Button 3 switches between inputs 5,6 and 7 on channel “C” (and lights up the corresponding LED)
A 4th push button allows you to quickly reset all relais to default, making inputs 1,3 and 5 “live”
An extra LED will blink each time you press a button, to confirm your command. (Blinker)
It allows you to connect 2 inputs to channel 1 and 2 each, and 3 inputs to channel 3.
Each input channel has a toggle switch and 2 or 3 LEDs indicating the active input. The actual switching is done using DPDT relays driven by Arduino (AT328p) via a simple 2N222A or even BD547 NPN transistor. It also has a potentiometer in A0, which drives a BD139 NPN Darlington transistor using PWM, allowing you to regulate the brightness of an LED strip that illuminates the mix table.
Button 1 switches between inputs 1 and 2 on channel “A” (and lights up the corresponding LED)
Button 2 switches between inputs 3 and 4 on channel “B” (and lights up the corresponding LED)
Button 3 switches between inputs 5,6 and 7 on channel “C” (and lights up the corresponding LED)
A 4th push button allows you to quickly reset all relais to default, making inputs 1,3 and 5 “live”
An extra LED will blink each time you press a button, to confirm your command. (Blinker)
Picture Gallery (build pictures)
The Arduino script (sketch in *.ino format)
| minidj.ino |
External connections between main PCB and LEDs, Relays and Buttons.
Schematic Diagram for the connections
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