Tiny Auto-measuring Cap Seven Segment With Mini

Introduction: Tiny Auto-measuring Cap Seven Segment With Mini

About: As a young kid, my curiosity in electronics was compelling.... why does thunder interrupt the radio reception? ....why does ROBOTs run without any wire?.... and I've been hooked on making thing ever since.

If you have learned about the capacitor(RF CIRCUIT).

the H bridge seems too complex, too many to adjust,

too many to change and too many to read for

just balancing the bridge ! (not include S.G and CALCULATES yet)


you don't even use one single finger, it's just tell how

many uF OR nf indeed the cap is whatever !


Portable !

Step 1: Material

i use 2 SSDs and 2 LEDs

to display the value and scale

for all resistor i use 330 OHM to limits the current down.

because the arduino mini have the MAX current limits !

and then the 1 LED is for the decimal point,

the other LED is as uF indicator.

Step 2: Tools

Step 3: Open the Phone Line Box and Clean All

use the "+" screw driver to remove all the copper bars and all the screws.

Step 4: Cutout the Hole for SSD

use the cutter to cut the cover of phone line box.

in order to embed the Seven Segment Displayer parts.

Use the hand drill to drill 2 holes in order to show

the u led and to show the point led.

Step 5: Soldering the SSD and the Resisters

use cutter to shorten the PCB, in order to fit it into the cover.

i didn't connect to the second digit to display

the "F" because the MAX current limits too !

Step 6: Testing

after soldering the resistors and mini.

And make some test.(10uF, 4.7uF, 1uF, 10nF, 47nF)


1)C<99.9 uF then turn ON c', d', e' .

in order to show the "u".

2)C<1 uF then turn ON c', e', g' .

in order to show the "n".

Step 7: Fixed the PCB With Hot Glue

use the hot glue gun to fixed the PCB on the cover.

Step 8: Coding

i use 3 know how to coding :


i use the library to display.

#include Multiplex7Seg.h

2)i turn the charge pin ON for 10 uS as a aquare wave

to ensure the min C >= 0.005 nF

in order to avoid mini crashing !

T = RC

if C=0

T/0 = divide by zero (error) !

so let the c(min) > 0.005 nF

3)i slow down the charge speed by increase R.
R = 240K. OHM, c = 1uF

so the T = 240 *1E3 *1E-6

T = 0.24 s

in order to increase accuracy.

Step 9: Embedding the 3v Battery Into the Box

a bit feature:

Since you could auto-measuring the capacitors, and then

the next thing you could do is making a network (RF TANK)

auto-turning(adjusting) !

Automation Contest 2016

Participated in the
Automation Contest 2016

Be the First to Share


    • Battery Powered Contest

      Battery Powered Contest
    • Plywood Challenge

      Plywood Challenge
    • Plastic Contest

      Plastic Contest