MagicQuartz Arduino Motor Shield Version

This is a simple “plug and play” version that is based on standard Arduino hardware. Please be sure to have read the basic information about the limitations of this Arduino version. This also contains very important security information – you don’t want to blow your computer’s USB ports!

Please note that I do not recommend buying hardware in order to build THIS Arduino version. It works, but the breadboard version is superior.

There are three expansion stages, which allow you to get in contact with MagicQuartz depending on what hardware you have available.

Stage 1: Arduino Uno only

“Stage 1” allows you to navigate in the MagicQuartz software. All you need is an Arduino Uno board (or a cheap Chinese Arduino Uno clone) that is connected to your computer. (Note: This will also work with the Arduino Nano, but you will not be able to proceed to stage 2 because you can’t fit the recommended Motor Shield onto the Nano. Of course you could wire up everything on your own … but in this case it would be much easier to build the breadboard version!)

Arduino MagicQuartz Stage 1

How to flash the firmware

These short instructions assume that are familar with avrdude and Unix-like systems. The instructions are given for Mac systems, but should be very similar on other systems (i.e. Linux). The commands are the same – you only need to modify the paths of the commands. Of course, you can also use Windows for flashing and accessing the Arduino board – you should be able to find instructions on how to do this on the internet.

  • Install the Arduino program, version 1.6.6, on your Mac:
  • For the original Arduino boards that have an FTDI chip (e.g. the Duemilanove/2009), install the official FTDI driver:
  • For the Chinese Arduino compatible boards, install the official driver:
  • In the Arduino program, try to flash one of the Arduino-Examples, e.g. the “blink” program, to see if it works.
  • Download the MagicQuartz firmware (see Downloads) and unzip the ZIP file to your Desktop. You should then have a MagicQuartz.hex on your Desktop.
  • Open the Terminal App, and type cd Desktop
  • Flash the firmware with the following command (this is ONE command):
    /Applications/ -C/Applications/ -v -v -patmega328p -carduino -b57600 -D -Uflash:w:MagicQuartz.hex:i -P /dev/tty.usbmodem26221

    For the Arduino Uno, change the baudrate to 115200 by replacing -b57600 with -b115200. The device name (the very last part of the command) should be different on your system. For the original Arduinos, it is like tty.usbmodemXXXXX or tty.usbserial-XXXXXXXX and for the Chinese compatible boards, it is tty.wchusbserialXXXXX, where XXXXX is a numeric or alphanumeric sequence. This sequence is different on each system and can change if you plug the Arduino board into another USB port. To find out the correct character sequence, delete everything behind “tty.” and press TAB. Then the terminal should automatically expand the command to the correct device or make multiple possible suggestions. In the latter case, pick the one that matches one of the above patterns.

  • Connect to the Arduino’s serial interface with the following command (on Windows, you can use putty with a baud rate of 57600 bps):
    screen /dev/tty.usbmodem26221 57600

    Again, replace tty.usbmodem26221 with the correct device as described above.

Welcome to MagicQuartz! Use the keypad on your keyboard to move the cursor on the screen and to increase/decrease values. To exit the “screen” program, press Ctrl+a then k then y.


Expansion Stage 2: Motor Shield and Transformer

This is where it gets exciting! “Stage 2” allows you to power and control a turntable that uses a synchronous or asynchronous AC induction motor.

Arduino MagicQuartz Stage 2

  • Be careful! This circuit generates high voltage. A small mistake can kill you!!!
  • You do this entirely on your own risk!
  • Do not connect turntables with AC motors that rely on phase-shifting capacitors. These were build for a fixed frequency only (e.g. 50 or 60 Hertz). The variable frequency that can be generated by MagicQuartz may damage such turntables.
  • Do not connect “modern” direct drive turntables.
  • Do not connect IEC protection class 1 or 01 appliances to the circuit. These are turntables that have a separate ground wire in their cable and a three pole power plug. In the unlikely event of a failure inside the turntable, the turntable’s chassis would draw a high voltage. Only connect IEC protection class II appliances. These are turntables that have a two pole power plug.
  • The picture above is not a recommendation for assembly 😉

If you still want to continue, you’ll need:

  • The Arduino Uno from “Stage 1”.
  • A laboratory power supply, capable of providing 1A at 18V.
  • The Arduino Motor Shield, sitting on top of the Arduino Uno. You need to cut the “Vin Connect” jumper on the Motor shield to avaiod possible damage to your Arduino, as describeded here.
  • A quality 230V to 12V toroidal transformer with at least 30VA. The recommended type, which is also used in the MagicQuartz DIY kit, is the RKT 5012 transformer, which can be obtained here: RKT 5012. The transformer will be used in reverse, i.e. to step-up the voltage from 18V to 230V (or 110V).
  • A quality 220nF/1000V capacitor. Recommended type is WIMA MKS-4.

Connect everything as shown in the following diagram:

Arduino MagicQuartz Stage 2 Schematic

Please note that the motor shield drives the two 12V windings of the transformer in parallel. This distributes the load across the two H-bridges in the L298 on the board. If your transformer has only one 12V winding, connect the wires to either the “A” or “B” terminal on the Arduino Motor Shield. Note that the other side of the transformer draws high voltage during operation. Be careful when working with the capacitor – it might be charged!

This is what to expect – the following two images show the generated high voltage with no load (turntable motor switched off) and with load (turntable motor switched on). Pretty poor quality, as stated above. Remember that this is supposed to be a sine wave … Depending on the transformer and the supply voltage, it might even be worse. The real MagicQuartz generates a very high quality sine wave.

MagicQuartz Arduino Sine No Load   MagicQuartz Arduino Sine Load 

Expansion Stage 3: Optical Sensor & Live Quartz

Please follow the instructions on this page!