My Arduino Capacitance meter!

[JoeyJoe]

I made it from the help of some online schematics and code.

Simple design really, looks messy from all the LCD wiring.

As you can see from the image, 1000uf cap reading at 994uf, fluctuates around 994 - 1000uf on the reading, so pretty accurate. Depending on how accurate the resistor in the charge circuit is.

Using this with blow capacitors, the reading is either 50% or less than the rated farads, or doesn't get a reading at all. Used it today and found a couple of bad caps with it that weren't blown.

Thinking of a way to have a green/red light system to detect if the capacitor is bad, but not sure how I would do this without having to tell it the rated farad of the cap.

I have a load of these arudinos, and LCD displays, may etch some PCB's to create a permanent one.

[goontron]

Re: My Arduino Capacitance meter!

very impressive! could such a weak little device be programed as an email notifier?

[shadow]

Re: My Arduino Capacitance meter!

very impressive! could such a weak little device be programed as an email notifier?

Probably...however to send emails...the Arduino will need an Internet connection. So you will probably need a wifi or a 3G module to go with it.
Email notifications would probably be easier on an embedded PC rather than a microcontroller. Something more like a Raspberry Pi or a BeagleBone Black.

[goontron]

Re: My Arduino Capacitance meter!

Probably...however to send emails...the Arduino will need an Internet connection. So you will probably need a wifi or a 3G module to go with it.
Email notifications would probably be easier on an embedded PC rather than a microcontroller. Something more like a Raspberry Pi or a BeagleBone Black.

thats about what i thought, do they have displays like the arduino?

[Mad_Professor]

Re: My Arduino Capacitance meter!

damn, I should've done this, I have atmega168 chip laying around. I build my own arduino from scratch getting rid of the useless crap, a using parallel port programmer. Quick and easy.

I wonder if you can build esr meter using arduino.

[shadow]

Re: My Arduino Capacitance meter!

damn, I should've done this, I have atmega168 chip laying around. I build my own arduino from scratch getting rid of the useless crap, a using parallel port programmer. Quick and easy.

I wonder if you can build esr meter using arduino.

I remember seeing something like an ESR meter running on an Arduino some time ago. Can't remember where though.

[shadow]

Re: My Arduino Capacitance meter!

thats about what i thought, do they have displays like the arduino?

What sort of displays are you talking about? An extremely simple one like the one pictured (2 line character display)? For the embedded PC's, they are geared towards more PC like displays. They have a HDMI connector so you can hook up a standard PC display. There are also display modules for them as well (usually something like a 3.5" to 4" touch screen). You can also hookup the simple serial and parallel displays to them, however I do not think they will have libraries built in to make it easy to use them (like an Arduino).

[budm]

Re: My Arduino Capacitance meter!

http://forum.arduino.cc/index.php?topic=80357.0

[JoeyJoe]

Re: My Arduino Capacitance meter!

You can use an Ethernet module to use it to send emails too. I have one of those as well.

You can also write some software on the PC that will listen to communications from the Arduino on the serial port, and use that to send the emails.

You can make an ESR meter, I think there is someone on these forums that has been working on one recently. Doesn't look too hard but its the code that is the hard part.

If your from the UK, I had plenty of LCD screens (Used to be eBay seller), as well as some *cheap* Arduinos.

[JoeyJoe]

Re: My Arduino Capacitance meter!

very impressive! could such a weak little device be programed as an email notifier?

I did also once make a fully working IRC client out of it. Complete with PS2 keyboard, 20x4 LCD, and commands to change rooms etc.

[ben7]

Re: My Arduino Capacitance meter!

LOL I wanna make one now. With ESR measurment too!

I wonder if there is a better way to test the capacitance, instead of having to wait a second or two xD

[JoeyJoe]

Re: My Arduino Capacitance meter!

LOL I wanna make one now. With ESR measurment too!

I wonder if there is a better way to test the capacitance, instead of having to wait a second or two xD

Here is the code that calculates the Farads.

 digitalWrite(chargePin, HIGH); // set chargePin HIGH and capacitor charging
 startTime = millis();
 
 while(analogRead(analogPin) < 648){    // 647 is 63.2% of 1023, which corresponds to full-scale voltage 
 }

 elapsedTime= millis() - startTime;
 // convert milliseconds to seconds ( 10^-3 ) and Farads to microFarads ( 10^6 ), net 10^3 (1000) 
 microFarads = ((float)elapsedTime / resistorValue) * 1000;