The Original Solarfidget

This instructable is outdated! For up-to-date instructions please visit the following instructables:

Original Solarfidget Lipo Edition

or

Original Solarfidget - No Batteries Included Edition

Using an LED-Ring (of 36 rgb leds) and an MPU6050 gyro/accel, this fidget calculates the position of a rotating pendulum that reacts to acceleration and gravity and simulates the effect of gravity on different bodies in our solar system (including Pluto).

For more information visit: https://github.com/fuzzybritches0/solarfidget

• 1x Arduino Nano or Arduino Nano 33
• 1x MPU6050 breakout board
• 1x battery charging breakout board
• 1x 36 addressable LEDs stripe (*)
• 1x HS170 380mAh LiPo battery with Molex plug
• 1x male Molex plug (**)
• 1x 3d-printed models of both the fidget and charger parts (***)
• 1x USB mini cable
• 4x 0.3x4x5 mm compressing spring
• 4x M3 locknut
• 4x M3 nut
• 4x M3x10mm bolt
• 4x M3x4mm bolt
• 8x cylinder magnet d=5mm,h=2mm,
• and a punch of cables one can salvage from old LAN cables or similar.

(*): Use a stripe with an LED density of 144 LEDs per metre.

(**): When buying a set of batteries there is normally a charger included from which you can salvage male Molex plugs.

(***): all four parts can be found as .3mf files in the design-solarfidget folder at: https://github.com/fuzzybritches0/solarfidget and can be imported directly into the 3d slicer software. If you need to make changes to accommodate your own hardware, use the solarfidget.scad file to do so.

To turn the lightfidget on or off hold the fidget horizontally, turn it thrice by 180 degrees. If there is no change, try doing it faster.

You can travel the following bodies in our solarsystem in order:

• Mercury (0.38g) (white)
• Venus (0.904g) (light blue)
• Earth (1g) (dark blue)
• Mars (0.3794g) (red brown)
• Jupiter (2.528g) (white grey)
• Saturn (1.065g) (yellow)
• Uranus (0.886g) (violet)
• Neptune (1.14g) (green)
• Pluto (0.063g) (pink)

To travel from planet to planet hold the fidget horizontally, turn it twice by 180 degrees. If there is no change, try doing it faster.

If you have sourced all the parts we can get going with the build. In the end, it should look something like this.

Place all eight magnets inside the charger and fidget so that the fidget and charger will only lock in place when the fidget is placed on top of the charger in the correct orientation; for example: place the magnets, next to the charger towers, with the same pole facing down. Do the opposite for the other two magnets. Repeat for the charger but reverse the poles. Use a crooked M6 key, place the magnet on the crooked end and use a hammer to fix the magnets in place.

Cut the USB mini cable about 10cm from the mini USB plug side. Carefully remove the PVC coat and the shielding. There should be four cables: one black, one red, one white and one green. Also remove as much of the hard plastic from the mini USB plug as possible - we only have limited space - but don't break the plug. Also make sure both the red and black cables are +5V and GND, respectively.

Now, we will work on the part of the fidget that houses all the electronics, that is, the top part.

Place the top part of the fidget in front of you facing the inside and having the charging towers face left. Connect the cables of the mini USB plug as follows from top to bottom: black, white, green, red; and add one cable to the red cable; there is an extra hole for that. Later, solder this cable to the battery charging breakout board and ground the board on the Arduino.

Use the M3 nuts and M3x4mm bolts to secure the cables. Clean the inside of the towers if there is loose or deformed material inside from printing the overhang. Use a longer M3 bolt to drive the nut into its place, enough so, that you can still push the cable into the hole below the nut. Then drive the nuts down all the way and secure the cables. Make sure there is only blank wire between the nut and the tower. Keep the blank wire short. If it's too long it may curl up around the bold, when fixing it, which we don't want to happen.

Connect the Arduino Nano to the mini USB plug. Push the Arduino inside its proper place. Push the battery charging breakout board into its proper place. Finally push the MPU6050 breakout board into its proper place, next to the battery, on the right side. Have the MPU6050 face up. On the MPU6050 have the X-axis point to the right and left.

Solder three cables onto the 36 addressable LED stripe. Note the direction of the arrows on the stripe and solder the cables on the right end. If the arrow points to the end of the stripe, it's the wrong end.

The picture shows the right end. Solder the cables on the back, pointing into the direction of the arrows. You can see a green cable stick out above.

Place the stripe around the inside of the fidget's top part. Start around the middle of the charging towers and continue clockwise.

Wire all cables around the battery compartment when you solder them on. Make sure there will be enough place for the LED stripe around the inside of the fidget, should you remove the stripe while you solder the rest. Keep the cables as short as possible. Ground all components on a common ground.

As I have mentioned before, at the beginning, solder the extra cable we add to the charging tower to IN+ on the battery charging breakout board. Ground it in the next step. IN- and BAT- are the same.

Solder BAT+ from the battery charging breakout board to VIN and ground the board on the Arduino. If you are using an Arduino Nano 33, bridge the contacts marked VUSB on the back of the Arduino with solder. The contacts are between RST and A7. For more information why this is required, please visit: https://support.arduino.cc/hc/en-us/articles/360014779679-About-Nano-boards-with-disabled-5-V-pins

Make sure your Arduino can run with 3.7V. My Arduino Nano was meant for 5V but it works quite well for a few hours.

Solder VIN from the MPU6050 to 3V3 on the Arduino and ground the MPU6050. Now, solder SCL, SDA and INT from the MPU6050 to A5, A4 and D2 on the Arduino, respectively. On the Arduino I used, A5 and A4 are for SCL and SDA. Your Arduino may differ but both the Arduino Nano and Nano 33 use the same analogue pins. Solder VIN from the MPU6050 to 3V3 on the Arduino and ground the MPU6050. Now, solder SCL, SDA and INT from the MPU6050 to A5, A4 and D2 on the Arduino, respectively. On the Arduino I used, A5 and A4 are for SCL and SDA. Your Arduino may differ but both the Arduino Nano and Nano 33 use the same analogue pins.

Solder two cables to the male MOLEX plug. When you connect a battery to the plug, you can see which cable is which. Make sure the plug and cable are properly isolated. Use shrink tubing. Never solder with a connected battery!

Solder the two cables to BAT+ and BAT- accordingly.

Now, solder + from the LED stripe to BAT+, DATA to D6 on the Arduino and ground the LED stripe.

Now, connect the battery to the MOLEX plug and place it inside the fidget.

That's how we figure out which cable goes where. Fix the cable with tuck tape.

Fix up the charging station by placing the four cables from the cut-off end of the USB cable inside the charging towers of the charging station. Don't forget to route the cable through the bottom part of the charger station first, before you wire it all up.

Here you see the blank wire inside the charger tower.

Use the 0.3x4x5 mm compressing springs, the M3 locknuts and the M3x10mm bolts to finish up the charger. Have the springs push down on the blank wires inside the towers. Clean the inside of the towers if needed.

Here you see the bolts looking out a little. Have them look out as little as possible, but make the charger work.

The fidget should get good contact when pushed down by the magnets.

We are not just yet going to close the fidget. We still need access to the LED stripe. So let's do the software.

Copy or link the folder in arduino-solarfidget/libraries/solarfidget into your Arduino/libraries folder. You can find the files at: https://github.com/fuzzybritches0/solarfidget

Place the files at: https://github.com/jrowberg/i2cdevlib/tree/master/Arduino/I2Cdev in a subdirectory in your Arduino/libraries folder

Place the files at: https://github.com/jrowberg/i2cdevlib/tree/master/Arduino/MPU6050 in a subdirectory in your Arduino/libraries folder

Place the files at: https://github.com/adafruit/Adafruit_NeoPixel in a subdirectory in your Arduino/libraries folder

Open the Arduino IDE and load the file: arduino-solarfidget/arduino-solarfidget.ino

Place the fidget on top of the charger, the charger on a level surface and connect it to your computer. Open the serial monitor. Compile and upload the programme to the Arduino. Wait for the Arduino to reset and start.

Look at the serial monitor and note down the calibration values. Now, open the file: arduino-solarfidget/arduino-solarfidget.ino and find the follwoing lines:

mpu.CalibrateAccel(6);
mpu.CalibrateGyro(6);
mpu.PrintActiveOffsets();

Comment those lines and uncomment the lines above starting with mpu.set??? and replace the values you just noted down for Gyro and Accel.

Save the file and upload the programme again.

Then, comment the following line, so the Arduino won't wait for a serial connection when not connected to USB:

#define SERIAL_DEBUG

If you want power saving, uncomment the following line.

//#define POWERSAVING

If in power saving mode, before you try enabling the fidget, hold it for a few seconds in your hands. If you have trouble enabling it, just flip it continuously by 180 degrees until it enables. Power saving mode is only active when the fidget is off and sitting still.

Save the file and upload the programme again.

Finally make sure the LED stripe is placed correctly in the fidget and the light of the pendulum is at the right spot. Do this by holding the fidget askew and wait for the pendulum to rest. Now, move the stripe either left or right to bring the light into the correct position.

After that, slide the other part of the fidget on.

You should all be set now. Have fun travelling our solar system.