multimeter

hello :D .

i will try to make a multimeter and i wanted to know if arduino is the best way/easy way for a begginer .

thank you

Are you doing this because you need a multimeter? If so, just buy one - it'll be much more capable at the same cost, and you can have more faith in the readings being accurate (besides, you'd certainly need a multimeter in order to build your own).

Making a multimeter that can do the same kinds of things as a commercial DMM is kind of a big project, especially for a beginner. Making one that can't - what's the point?

There does exist a somewhat similar device, made with an ATMEGA328p, that will identify parts connected to it (including resistance, capacitance, gate charge of mosfets, voltage drop of diodes, etc) - I don't think the numbers are all that accurate, but the whole thing is under $15 shipped, .

If you really want to do this, start with a voltmeter. The Arduino's ADC can read 0-5 or 0-1.1VDC. (The ADC reads from 0 to 1023, but you simply have to scale it proportionally to get volts.)

With the optional 1.1V reference you can read down to about 1mV, and you'll have 1mV resolution. It's unlikely that you'll need to read lower voltages, but if you do, you can add an amplifier stage.

For higher voltages, you can use a voltage divider (2 resistors), but you'll also need over-voltage protection in case you connect it with the wrong voltage-range selected or to an unknown voltage that turns-out to be too high.

A basic DC voltmeter is fairly easy, and the hardest part is probably the LCD display.

For reading AC, you'll need a precision rectifier circuit and you'll need some "simple tricks" to approximate RMS, or you can actually calculate RMS.

To read negative voltages, you'll also need a rectifier/inverter and some way of knowing the voltage is being inverted.

the best way/easy way for a begginer .

You could build one from a [u]kit[/u].

Many years ago, kits were "the thing". There was a company called [u]Heathkit[/u], and you could build a TV from a kit!!!!

But with 3rd-world labor and modern-automated assembly lines, you can build a TV with almost zero labor cost, so building stuff yourself that's otherwise mass-produced and mass-distributed doesn't make economic sense.

thank you for advice ! i can make a C# interface , no LCD . ADC was in plan .

DVDdoug: Many years ago, kits were "the thing". There was a company called [u]Heathkit[/u], and you could build a TV from a kit!!!!

I built my first oscilloscope from them.

Only reason I had to ditch it was the focus knob had a tapped pot which broke

http://arduino.cc/en/Tutorial/ReadAnalogVoltage

If you just want a meh-quality ADC that connects to the computer, than the arduino is a good choice.

I have built a lot of Heathkits, too. Sigh.

is not a good idea ? i am a begginer and it is hard to know allllll :'(

Since you haven’t given us any specs about what you want, we cannot make very specific recommendations.

well start indeed with a voltmeter trya battery of 1.2 volt, or a cr2032 now a 9 volt will be too much, so youwill need a relais to make a voltagedivider.

electronic_ardu: is not a good idea ? i am a begginer and it is hard to know allllll :'(

I would suggest you find a simpler project or simplify this one.

Limit yourself to a voltmeter.

To have any useful range you will need to incorporate range switching .

Just use the onboard adc . Lots of external components required

Don't bother with an LCD either , get the basics right first. Use serial to output measured values

ok , voltmeter will be .
maybe in the future i’ll do something bigger .