The Nice Resistor lamp makes coloration codes readable

Resistor coloration codes are nice, as a result of they make it straightforward to determine a resistor’s worth by referencing a easy chart (or memorizing that chart). However resistors are additionally very small and their coloration bands are exhausting for many people to see clearly. As a substitute of shopping for a magnifying glass, J constructed the Nice Resistor lamp that reproduces a resistor’s coloration code at a a lot bigger scale.

To show a resistor’s worth, one should first discover that worth. To measure the resistance of unknown resistors, J used an Arduino Nano and a 16-bit ADC (analog-to-digital converter) to measure the enter and output voltages of a voltage divider circuit. One of many resistors in that circuit has a recognized worth, whereas the second is the unknown resistor being examined. The three recognized values let the Arduino calculate the unknown worth, which is the resistance of the examined resistor.

The Nice Resistor then shows the resistor worth in two methods. First, it exhibits the numerical worth on a small 0.96” monochrome OLED display. Second, it illuminates NeoPixel RGB LEDs in a tube to match the resistor’s coloration bands. Every coloration band part sits between foam dividers to isolate the colours. The Arduino determines the colours by wanting on the first three digits of the resistance, which correspond to the primary three bands. The fourth band is the multiplier. The fifth band specifies the tolerance of the resistor, although it isn’t clear how the Nice Resistor determines that tolerance or if J at all times units it to pink (a free tolerance).