Go Down

Topic: Detect grounding of a external circuit (Read 991 times) previous topic - next topic

Devigan

Hi ,
I understand how to sense 12 V and higher circuitry. Can someone walk me through how to apply to this sensing grounding of external circuit.
Newbie :-?

CrossRoads

Can you put a pullup resistor on it (from 5V) and see if the grounded thing goes high?
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Devigan

Not use about pullup resistor.
Basically I have access to a switch which complete the circuit by the providing ground to power up an external unit. How can I work with this to sense when the unit is on in the arduino.

Graynomad

What is the "external unit"?

It's possible you can detect the unit's power supply level when the switch is open and 0v when closed. But it depends on what the "unit" is.

This is essentially what Crossroads said, the "unit" is a pullup resistor, so now that I think about it why can't you just use a pullup resistor?

______
Rob

Rob Gray aka the GRAYnomad www.robgray.com

Devigan

sorry I am newbie what is a pullup resister

Graynomad

A resistor from the Arduino pin to 5v.

But you haven't answered the question, what is the "unit"?

______
Rob

Rob Gray aka the GRAYnomad www.robgray.com

Devigan


Go Up