Electric Eel Wheel Builder's Guide (Electronics)

By: Maurice Ribble

1/27/2010 Version 1.2.00

The Electric Eel Wheel hardware and firmware are open source under a Creative Commons Attribution 3.0 License.

Required Tools

  • Soldering iron and solder

  • Flux remover spray (rubbing alcohol and a toothbrush also works good)

Parts

Image

Qty

Description



1

Custom Circuit Board

Eagle Files here



1

10K Potentiometer



1

Dial for Potentiometer



1

On-Off Switch



1

L298



1

Heat Sink



1

28 Pin DIP Socket



1

ATMega168

With Arduino bootloader and Electric Eel Wheel software loaded


If you did not buy the kit you will need to use the Arduino software to load the Electric Eel Wheel Software onto the device



1

16 MHz Crystal



1

5V Regulator

LM7805



4

1n4004 Diode



2

22 pF Capacitor



3

0.1 uF Capacitor



2

10 uF Capacitor



1

100 uF Capacitor



3

10K Ohm Resistor



1

Mini Push Button



1

2 hole 3.5 mm Screw Terminal



1

2.5 mm DC Power Connector



1

Wires and 2 insulated disconnect F from a local hardware store



1

DC Motor



1

12V Power Supply



Circuit board Assembly



Image

Description




Place the two 22 pF capacitors into the circuit board as shown. Bend the wires sticking through the back outwards a little to hold them in place. Flip the board over and solder them into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.




Place the three 0.1 uF capacitors into the circuit board as shown. Bend the wires sticking through the back outwards a little to hold them in place. Flip the board over and solder them into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.


You must bend the middle capacitor flat as shown in the picture so that none of the metal legs of capacitors touch.



Place the three 10K ohm resistors into the circuit board as shown. Bend the wires sticking through the back outwards a little to hold it in place while soldering. Flip the board over and solder it into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.




Install the mini push button into the circuit board as shown. It will snap into place when it is properly installed. Flip the board over and solder it into place.




Place the four 1n4004 diodes into the circuit board as shown. Bend the wires sticking through the back outwards a little to hold it in place while soldering. Flip the board over and solder it into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.



Place the 16 MHz Crystal into the circuit board as shown. Bend the wires sticking through the back outwards a little to hold it in place. Flip the board over and solder it into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.



Put the 28 pin socket into the circuit board as shown. There's a notch in the socket which should line up with the notch in the image of the socket. The notch will help you align the microchip when you install it later. Turn the board over and hold the socket in with a finger, tack two corners pins to keep it in place then solder the rest of the pins.



Place the two 10 uF capacitors into the circuit board as shown. These are polarized capacitors which means you must solder them in with the correct orientation. The longer wire should go into the hole marked with a plus sign. Bend the wires sticking through the back outwards a little to hold them in place. Flip the board over and solder them into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.



Place the 2 hole 3.5 mm screw terminal headers into the circuit board as shown. Turn the board over and solder it into place.



Place the 100 uF capacitor into the circuit board as shown. It is a polarized capacitor which means you must solder it in with the correct orientation. The longer wire should go into the hole marked with a plus sign. Bend the wires sticking through the back outwards a little to hold them in place. Flip the board over and solder it into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.



Place the DC power connector into the circuit board as shown. Flip the board over and since it fits loosely into the holes make sure it stays properly aligned while soldering. Solder it into place (just keep adding solder until the holes fill with solder).



Place the 5V regulator into the circuit board as shown. Make sure you bend it so that it is flat before you solder it into place. Flip the board over and solder it into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.



Place the L298 into the circuit board as shown. Flip the board over and solder it into place. Then use wire cutters to clip off the extra wires sticking out the back; cut close to the end of the solder joint.



The next two components get soldered to the back of the board. Make sure you flip the board over before you place them.


Place the on-off switch into the circuit board as shown. Flip the board over and solder it into place.



Place the 10K potentiometer into the circuit board as shown. To make this easier bend the legs on the side of the potentiometer in slightly so they slide into the holes easier. Flip the board over and solder it into place.



Install the ATMega168 into the 28 pin socket you previously soldered onto the board. This chips have a dot and/or notch on it. This must line up with the notch in the sockets.


Sometimes it helps to bend all the pins on the chip slightly inwards before installing it into the socket.


Press firmly until it don't go in any more. Look carefully to make sure all the pins went into the socket and didn't get bent to the side while pressing them into the socket.


  • Use flux remover spray or rubbing alcohol/toothbrush to take the flux off the board (Yes you really need to do this).

  • Compare the board to the picture at the end of this document to make sure everything looks correct.

  • Look at the solder joints to make sure they look good.



1) Connect the red wire to the M+ and the black wire to the M- screw terminals on the motor controller

2) Connect the terminals into the motor

3) Turn the power switch off

4) Plug the power supply into the motor controller




The first time you turn on the power you need to do the following steps to configure the motor controller.


1) Turn the potentiometer all the way counter-clockwise

2) While pressing the button on motor controller turn the power on and then release the button

3) Turn the potentiometer all the way clockwise and then press and release the button

4) Turn the potentiometer to it's middle position and then press and release the button


Now you should see the motor does not spin when the potentiometer is in the middle. It should spin one direction when you turn the potentiometer clockwise and spin the other direction when you turn it counter-clockwise. Once this is correctly setup you should never need to press that button on the motor controller again.


Congratulations the motor controller is now configured!

Here is an image of the finished circuit board.




Go to the next builder's guide for the Electric Eel Wheel's structure.