Reading PWM from 12v motor

Projects Programming
1

I am working on a project right now. And i want to read PWM on a 12v DC circuit that is comming off of a controller to run a pump. The end goal is to read the commanded output to the pump and use a pressure sensor down line to ensure the system is working properly. Set limits and if the system pressure drops (or raises too high) to send a signal to cut power to another component using a servo.

What would you all recommend to:

-Reduce voltage to install the Arduio to an existing 12v system

  • Most importantly - read pwm off a wire running to a 12v pump.
2

Here is a simple circuit for that:

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This one shows an analog input but you can configure it for digital input or use a digital pin.

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3

If you mean "power the Ardiuno from the 12V supply" then a Buck Converter that outputs 7V can be used on the Vin pin or power jack. Shouldn't need to source more than 500 mA.

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4

John,

I apologize for my ignorance on the subject. But i guess thats why i am here. My research has me a bit nervous here. Voltage spikes and drops seem to be a bit of a general concern. Would a simple buck converter be a safe option?

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5

You can use a 12V Power Filter to filter out noise if you think that might be causing problems in your circuit.

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6

For reading the PWM signal try using the PulseIn() function.
Arduino Reference: PulseIn()

7

Also, before connecting your signal to A1, you can use a voltmeter to ensure the voltage never spikes over 5V.

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