Multimeter Diode mode

Projects General Guidance
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Can anyone give me tutorial to get multimeter diode mode reading using arduino and adc with lcd ?

2

Somewhere out there is the code for a full component tester , like the ones you see on eBay .

Google is your best friend

3

Thank you very much for your reply.

I don’t need component tester.

I want to get diode mode readings from arduino. Without using multimeter.

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It is measuring the diode forward voltage: Diodes - SparkFun Learn

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Hi, @rusiruneranjan

Have you Googled;

arduino diode tester

Tom... :smiley: :+1: :coffee: :australia:

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The diode test function on a multimeter is normally just a constant current source of a few milliamps. This current is passed through the diode, and the meter indicates the voltage across the diode.

You don't even need a constant current source, as a first attempt you could just connect a (say) 1kΩ resistor between +5V and an analogue input, connect the diode under test between the analogue input and ground, and just measure the voltage on the analogue input.

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The Arduino component tester would give you the answers you need for a diode tester !!

If you just want to know if the diode “works” use a DPDT switch with an led /resistor/battery in series so you can switch the direction of the voltage - one way the led lights, the other it doesn’t .

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Thank you very much for your support. I’ll go with these information and post here what I have done.

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you would need to add a lcd display if you wish to use one.

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Drop a "few" microamps from Vcc through a big resister; I'd try up to a MegOhm, to the component under test between an analoginput and ground.
If it is a silicon diode then you should get an ad value near 1023 x 0.7/4.5 = 160
If it is a 1.8 Volt red LED, you should see faint red and get near 1023 x 1.8/4.5 = 410
If it is a 2.6 Volt blue LED, you should see faint brilliant blue and get near 1023 x 2.6/4.5 = 590
The 4.5-ish Volts at VCC on mine when powered from USB may vary a little bit.

Once you can see sensible measured numbers on Serial.print on your computer, there are quite a few things to do to get the LCD displays to work.

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