12v illuminated flick switch to Arduino

I "think" I have this but wanted to check. I'm looking to use illuminated 12v flick switches with an Arduino.

I want them as bright as possible so am going with 12v and drop the voltage using voltage dividers before attaching to one of the digital pins.

I've figured out the resistor values (14k ohm, 1k ohm) to drop the 12v to 5v but have a question.

Can I do away with the multiple 1K ohm resistor and run all of the switching into one or do I need one for every switch?

Also, I'm a complete noob with this so is this even a good idea, will I fry anything?

Illuminated switches have three connections, input, ground and output. The bulb/LED is between output and
ground. I presume you've just not shown the ground connections on that diagram as Fritzing has no symbol?

I think you mean 1.4k and 1k. Use 1.5k and 1k as 1.5k is a more common value. You need one resistor
divider for every switch since each switch is a separate signal.

Another way to do this is use a resistor/zener divider, say 10k+4V7, or just use a >= 10k resistor and let the
input protection diode carry the current (not as robust though).

Thanks for the feedback, you're right about the resistors, dropped a zero along the way. Putting a 1.5k resistor would drop the voltage to 4.8 volts, is that enough to read high on the Arduino pins?

Also, have I got the wires in the correct place, in between the resistors?

Also, this is going to be built into a wooden structure in my kids room, do I need to worry about heat dropping the voltage so much?

With regards to ground connections, I reworked the diagram with the correct wiring, does that make more sense?

Thanks

Hi,
Ops diagram;


That diagram has those switches shorting the 12V supply to gnd when in the left position, don't use fritzy, I understand that they are not the switches that you are really using.

What switches are you using?
Please post a link to spec/data of the switches.
Can you post a picture of your switch please?

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom.. :slight_smile:

maxmon:
Thanks for the feedback, you're right about the resistors, dropped a zero along the way. Putting a 1.5k resistor would drop the voltage to 4.8 volts, is that enough to read high on the Arduino pins?

3.0V reads HIGH, < 1.5V reads LOW, guaranteed for 5V operation of ATmega chips (see datasheet electrical
characteristics).

Note this means that 3.3V logic signals can just be read by a 5V Arduino reliably...