Arduino-based electric menorah

To build using make, install the arduino-mk package. I use Ubuntu, so the import path is relative where files live in the apt installation. Alternatively, one can import it into the Arduino GUI if they desire.

Building the menorah is fairly straightforward, as is shown by the diagram below. All resistors in the diagram are 100 Ohm. The blue LED is the Shamash. Since the candles of the menorah are typically placed right to left and lit left to right, the circuit in the diagram below is oriented so the Shamash is on the right-hand side of the menorah. Then, when the LEDs light up, they light up from left to right.

The amount of LEDs can be configured via the blue, green, and yellow wires connected to A0, A1, A2. The analog inputs are read digitally as GPIO inputs where the values make a 3-bit number where A0 is the least significant bit. To set a bit low, connect its corresponding wire to ground. The number to set is one less than the amount of LEDs to be lit. To change the number of lights, first set the enable pin (purple on the diagram) to ground (set the switch so all lights are off), set the desired number of lights, then flip the switch to set the enable pin to high. The lights will light up with a small delay between LEDs, then remain on until the enable pin goes low again or the Arduino is powered off.