Prototyping & Engineering Electronics Kits

Magic Mandala Kit Guide

odysseyboard.com

Please refer to www.odysseyboard.com for a PDF updated version of this guide.

Magic Mandala Guide version 1.0, February, 2018. Copyright © Odyssey Board, LLC

Disclaimer:

Odyssey Board equipment is recommended for ages 12 and up.

***Choking Hazard: The kit contains small parts. Do not allow kits to be used around small children.

Do not use kits in ways other than intended in this booklet.

Do not exceed 5 volts of power input.

Do not touch parts while spinning.

Strobe lighting and fast flashing lights can have a negative effect on some individuals. Do not use this system if you have photosensitive epilepsy or other light sensitive conditions.

Mandala Kit Parts Inventory…………………….…….Radial Symmetry……………………………………...Strobe Created Radial Symmetry.………………….Calculating Strobe Rate……………………………..Magic Mandala Assembly...………………………...Preparing the Disc……....…………………………...Extensions…...……………………………………….

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Note: This kit is intended as a follow up add-on to the Odyssey Board Basic Kit and assumes prior knowledge, such as the introduction to the Keyestudio Uno, Odyssey Board system, and basic coding explained in the Basic Kit Guide. If you purchased this as a stand alone kit, the introductory content contained in the Basic Kit Guide is available for download on the Odyssey Board website.

odysseyboard.com/learn.

Magic Mandala Required Parts

Microcontroller

PotentiometerBlock Socket Block Switch Block

F/F Jumper Wires*

Odyssey Board Base

9v battery adapter

Dowels*Wire Clips

Magic Mandala Add-On Kit Parts

CD Motor with Shroud*

3w LED Brick*

The Magic Mandala Add-On Kit only includes the parts listed below, which are not included in the Basic Kit.

CD Motor with Shroud3W LED BrickCD

10 cm and 30 cm male to male jumperDisc adhesive putty and extra dowels3 F/F Jumper wire.

10 cm & 30 cm Male to Male Jumper wires*

CD and sticky putty*

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*Parts included in the Add-On Kit

What is Radial Symmetry?Radial symmetry is a condition of having similar parts arranged around a central axis.

Radial Symmetry is found throughout nature, art, and architecture.

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The following activity will explore how a spinning disc with a varying strobe light frequency creates a living kaleidoscope of surprising and mesmerising radially symmetrical images.

Strobe Created Radial Symmetry

Now imagine flashing the light exactly twice per second. The light would flash two times as the disc spins one rotation. The observer would see the original image and a second image rotated 180 degrees.

Imagine a disc with a centered equilateral triangle in a perfectly dark room spinning at one rotation per second. Also imagine a very brief flash of light happening once per second. Since the disc is illuminated at the same rate it spins, the image would appear to be still.

If the light flashed three times per second, you would see the original image, the image rotated 120 degrees, and rotated 240 degrees.

Strobe:RPM=1

Disc:RPM=11=1

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If original image was a line drawn from the center to the edge at 12 o’clock, at a 1:1 flash to spin rate you would see one line.

Ratio of Flash to Spin Rate.At a 2:1 flash to spin rate, the line would appear to continue through the center and align with 12 o’clock and 6 o’clock.

At a 3:1 flash rate, the line would extend from the center to 12 o’clock, 4 o’clock, and 8 o’clock.

Calculating the Strobe Rate.Imagine increasing the spin rate to approximately 1800 RPM. To achieve a 1:1 ratio and have the image appear in its original form, you would need to flash the light at the same frequency as the spinning disc. However, a flashing light (strobe) is not measured in revolutions per minute. When we measure the light’s blink rate, or strobe, we use Hertz. This is measured in blinks per second. We can calculate the strobe rate from the spin rate. To use the same unit of measurement, convert the revolutions per minute to revolutions per second. There are 60 seconds in one minute so 1800÷60=30. The spin rate is 30 revolutions per second. Since the strobe is flashing at the same rate, it also flashes 30 times per second. Therefore, a spin rate of 1800 rotations per minute is equivalent to 30 blinks per second, or 30 Hertz.

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Build the Magic Mandala System

Set up the Odyssey Board with the blocks shown. The arrangement of blocks does not matter with the exception that the LED brick must face the CD.

This system will require three circuits: 1. A circuit using 3 volts to powers the 3v the motor using the switch.2. A circuit controlling the signal to the strobe light.3. A circuit sending 5v to the potentiometer.

Always unplug the power when changing your circuits.

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1. Connect one wire from the switch to a blue GND pin on the UNO.2. Connect the other wire from the switch to a 10 cm Male to Male

wire. (This wire connects to the black quick connect button on the back of the CD motor.)

3. Connect the 30 cm M/M wire from the red quick connect button on the back of the motor to the 3v Female header pin on the UNO.

Warning: Do not connect the motor to 5v. CD motor connected to 3.3v.

The first circuit provides 3 volts of power to the CD motor controlled with a self locking switch.

Note: The orientation of the blocks shown is for identification and wiring purposes. Follow all instructions for proper operational orientation.

Build the Magic Mandala System (cont.)

1. Connect the blue wire to male GND pin on A0.2. Connect the red wire to the red male 5v A0 pin to provide constant current to the pot.3. Connect the yellow (signal) wire to the male A0 signal pin.

Always unplug the power when changing your circuits.

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1. Connect a F/F wire (shown in blue) from a male GND pin on the UNO to the G pin on the LED brick.

2. Connect a F/F wire (shown in red) from a male 5v pin on the UNO to the V pin on the LED brick.

3. Connect a F/F wire (shown in yellow) from the signal D8 pin on the UNO to the S pin on the LED brick.

The second circuit controls the signal to the 3W LED brick allowing you to change the frequency at which it blinks. For best results, try to mount the LED brick at the same height as the center and about 3-4 inches away from the motor.

The third circuit sends a 5 volt signal to the 1k potentiometer. The signal (center) pin of the pot will vary the voltage as the knob is turned, which will control the blink rate of the 3W LED.

Note: Remember to turn the LED brick so that it is facing the center of the CD motor.

Once the Odyssey Board is set up and the circuits are wired, go to odysseyboard.com/learn and download or copy and paste the code for the Magic Mandla. When the code is successfully uploaded to the UNO, the 3W LED should rapidly blink and change in rate when adjusted by the potentiometer. The code takes the value from the potentiometer and maps it to the blink frequency on the LED. The lowest rate is close to 1800 blinks per minute which should be very close to the spin rate of the CD.

1. Take a blank CD and trace the outline onto a blank piece of paper. While the CD in in place, try to mark the center of the circle for later reference. Take a drawing medium of your choice, colored pencils, markers, paint, etc. and create an image within the circle that has been drawn. Any image will work, try drawing both regular geometric or realistic images and abstract creations. Once you are finished drawing, cut the circle out and attach it to the front of the blank CD using 3 or 4 small pieces of adhesive putty.

2. Place the CD onto the CD spindle. Once the Arduino is connected to a power source and is running the strobe sketch, turn the rocker switch on to begin the CD spinning. Begin with the knob of the potentiometer turned so that the blink rate is at its slowest point. Slowly turn the knob and see how the blinking light changes the images you see on the spinning disc. Try turning the knob so that you see the original image and it stops spinning. When you find this point, you have matched the spin rate and the blink rate. (1:1 ratio)

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Creating the Disc

When the strobe sketch is open on your computer and you are connected using the USB cable, open the serial port. This number shows the blink rate at blinks per minute. As you turn the knob, make observations as to how the image changes as the ratio of blinks to spins reach certain points. As the blink rate slowly increases, what happens to the direction the image spins. Can you predict when the image will appear twice and rotated 180 degrees? If the original image is a centered equilateral triangle, what would the image look like when the blink to spin ratio is 3:1.

Using the Serial Monitor to Observe Blink Rate

- Create an image divided into equal parts so that with blink ratios reach a point, the image will be reproduced. For example if lines are drawn extending to 12, 3, 6, and 9 o’clock and the word LOVE was written with one letter on each line in its respective position, the word would appear reassembled four times when the blink to spin ratio reaches 4:1. -Try to design an image that will appear at a 2:1 blink:spin rate, another image that would appear at a 3:1 blink rate and a different image that would appear at a 4:1 blink:spin rate. -Create a yin yang design and create two halves that would create an interesting effect when the two sides are superimposed at a 2:1 ratio.

Extensions to try.

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