Magnify you resistor color code with this resistor measuring color code lamp.

To this day i still have trouble to decode the color code of resistors. I hope this device will help me to learn them properly.

NOTE: ~~The multiplier band is of by one digit / color!~~

~~Errors are there to make and gain knowledge (: -I'll correct the code soon.~~

UPDATE [16.11.2022]: Code should work now as intended

(I hope i could describe the building process somehow properly. Please give me any feedback on what to write in more detail.)

Watch the demonstration video here: youtube.com/watch?v=2C_KpQk_63M

More Technical details can be found here: https://hackaday.io/project/188104-the-great-resistor

Supplies

4 x Skewer sticks
one pair of unbroken chop sticks
A sheet of normal white paper (Din A4)
A sheet of black foam rubber (Din A3)
2 x Hot glue sticks
2 x Alligator Clips
1/2 Breadboard (depending of the length of the bottle)
1 x straight identical plastic bottles
1 x Arduino nano
1 x i2c ADS1115 adc module
1 x i2c SSD1306 OLED display
15 x WS2812 144 LED/m
2 x WS2812 soldered on tiny PCB
a few cables (thin silicone cables work the best for me)
double sided stick tape (VHB Tape)
1 x 33k resistor
1x 10 µF Capacitor
a few pieces of aluminium stick tape

Step 1: The Enclosure of the Resistor Lamp

The first thing is to find a straight bottle in which you'll pack your light installation. Cut the bottle at the end were the cap is placed. The length of the bottle will be your resistor length. Cut the second bottle at the 1-2 cm above bottom, so you can form a cylindrical form. It helps to cut 4 slices in to the short bottom part, so you can push it over the lengthy bottle, so i closes up with ease.

Step 2: The Light Installation

The light installation is based out of 15 WS2812 (neopixels). You'll need the high density WS2812 strip with 144 Led per meter. Cut out a segment with 15 Neopixels and stick it centered to the unbroken pair of chopsticks. Look for the Datasheet of WS2812 ans solder a wire to the Vin, Grd and DIN.

Light blocking element:

Trace or measure the radius of the inner diameter of the bottle onto the black foam rubber and cut it out. It should fit loosely into the open end of the bottle. Repeat this step 10 times. Every resistor band need two light blocking elements.

Stack those 10 circles as good as possible on top of each other and stick 4 skewing sticks orthogonal to the plain through the rubber foam(see green dots on the picture). Cut at the red marked position at all 10 circles, at best at once, just like the skewing sticks. Separate all 10 of the elements roughly centered on the 4 skewing sticks. Push the WS2812 strip sticks of the unbroken pair of chopsticks through the red marked cutten lines. Now move the light blocking elements in this order: 1 || 2 || 3, 4 || 5 || 6, 7 || 8 || 9, 10 || 11 || 12, 13 || 14 || 15. The numbers represent the numbers of WS2812 and "||" represents one light blocking element.

Step 3: Adjust and Finish the Lamp

You should end up with the light installation as shown in the picture. To move the light blocking elements to the proper position takes some time. I used a screwdriver to adjust every position of each element at all 4 contact points of the the four skewing sticks.

Take a sheet of paper and cut it in the dimensions of the circumference of the bottle in height and the width of the length of the used bottle. Wrap this paper around the light installation and push it into the bottle. Test the strip of WS2812 now to see if its connected properly and id any element has to be readjusted.

When everything is in place at your discretion, cut or drill a hole through the short end-cap (short piece of the bottom bottle) pull all 3 cables through and close the 'Great Resistor'.

Step 4: Resistor Arms and Base

To form the arms of the resistor cut a V-shaped segment out of the hot glue stick, make it hot and shape it. When the shape satisfy you stick aluminium tape around everything, to give it a metallic look. Stick the arme to the middle of the ends of the resistor, to give it his resistor look

Since the arms of the resistor go under the breadboard on the back side i also used one hot glue stick for the front site. Tha also included the described 90° bending method. This is being sticked with VHB Tabe on the bottom side of the breadboard.

Keep the ende of the resistor arms uncovered from aluminium tape so the VHB tape can grip more.

Step 5: The Base

The base contains all the electronics and modules. On the bottom of the breadboard I stuck the Arduino Nano in the center and the ADS1115 next to it. The OLED display (SSD1306) was placed on the top. Before you place everything drill two holes for the alligator clips. The distance of the holes should be less than the total width of a resistor including its contact wires (arms) you want to measure in future. Look for a drill diameter, so the alligator clips fit tightly into the holes.

Use a VHB Tape to stick the resistor arms under the breadboard.

Step 6: Theory

We are measuring the voltage across R1 and the voltage across both resistors. The ratio from U1 and U2 is equivalent to the ratio from both resistors. Since R1 is known (the 33k Ohm resistor) It is easy to figure out the second Value of the tested resistor. You have to measure the resistor R1 with an digital multi meter, so you get the exact value of it. You have to enter the exact value into my code. (exchange "33250" in line 111 in the code with your measured value of R1).

Step 7: Wireing

After you placed all modules they have to get connected. Take your time and copy my wireing.

LED 0 & 1 goes to the lef and right side end of the hot glue stick functioning as spacer. See the green glowing regions from the picture of the bottom side of the breadboard.