In this instructable we will create a chanting menorah for Hanukkah.

Every day we light another candle, this will be done by simply pressing a push button. The middle candle (called shamash - servant) is always lit.

The music is played from a microSD card, through a simple speaker. I used an old PC speaker for that purpose.

Step 1: Bill of Materials

For this menorah you need:

Arduino (I used UNO, but nano can be used also)
SPI Micro-SD card for Arduino (you can also use data-logger shield).
NPN transistor. I recommend 2N2222.
9 LEDs.
9 1K resistors.
1 10K resistor.
A speaker.
Wires.

Step 2: Wiring Scheme

Wire all together using the attached scheme.

For the microSD card:

VCC goes to 5V on the Arduino UNO (for power)
GND goes to Ground on Arduino UNO
D0 (MISO) goes to pin 12 on Arduino UNO
D1 (MOSI) goes to pin 11 on Arduino UNO
CLK (SCK) goes to pin 13 on Arduino UNO
D3 (CS) goes to pin 10 on Arduino UNO

The push button is connected to an analog input with a pull-up resistor. It is a good solution if you are out of digital pins.

The speaker is connected via a transistor so that the digital pin won't draw too much current. I added the 2N2222 pinout for reference.

Step 3: Code

To play the wav file I used the TMRpcm library found here.

A lot of forums tell you to put delay in the loop() in order to play, but this is wrong. The library is asynchronous, it means you can play a file and continue executing other code. To do this, write: tmrpcm.play("1.wav");. Then, check if the file finished playing using if (tmrpcm.isPlaying() == 0).

For example, to play continuously, use:

if (tmrpcm.isPlaying() == 0) {tmrpcm.play("1.wav");}

All the code is in the attached zip file. You can also find there the WAV file with a Hanukkah song, I used Audacity to convert it to unsigned 8 bit PCM wav audio, at 16000Hz. I also doubled the playing speed.