3 replies to this topic

[Kaya B.]

Hello, We have a telephone hybrid device in our studio. And it has a remote output that you connect a button and 24v led. When you push the button it connects the telephone to our broadcast system and a 24v led lights. I did the remote box and it is not so useful. So; I want to make a new one on netduino plus and give a little software to our director. So; I know well about programming but I don't know how to connect the 24v light out to netduino and where will the button connect? analog or digital? Can you help me which resistors or etc to use? Thanks for your helps. Greetings from Turkey.

[carb]

Kaya,

Welcome to the forum.

A simple voltage divider should work, see the attached post Watching Voltage through Analog
If you only need to see if the LED is On or Off you can use either a Analog or Digital input. You will want to drop the voltage down to < 3.3 vdc.

By the way the heading says 12 volt but the text says 24 volt. If it is 12 vdc you can change the ratio of the resistors.

Chuck

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[Kaya B.]

Thanks Ckuck. I'm not sure it is 12 or 24 volt. I'll check with multimeter. Also; how can i simulate the pressing the button?

[carb]

Thanks Ckuck.

I'm not sure it is 12 or 24 volt. I'll check with multimeter.

Also; how can i simulate the pressing the button?

You read the voltage between the 2 resistors and ground (make sure that you are across the 10K ohm resistor or the low value of the voltage divider, across 1 resistor is 21.6 vdc the other 2.4 vdc). I reccommend reading the voltage with a voltmeter before connecting the Netduino so as not to apply more than 3.3 vdc.

If you use a digital input when the io is false or for an analog when it reads 0 or < 0.05.

Chuck