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Wiimote modifications
From Smoothboard
These modifications can enhance your Wiimote IWB setup, targeted at improving the functionality of a permanent installation. We would like to acknowledge Dirk Schouten for his research and publication of these modifications.
In a classroom, a teacher most times uses a whiteboard fixed to a wall and the Wiimote will be fixed to the ceiling. In this environment it's a bit clumsy to every day find a ladder, climb to the Wiimote, press some buttons and have another teacher perform the connection. The same goes for changing the batteries. Below are the steps to take in this modification project. You have to take your Wiimote apart and solder a few wires in it. The wires connect to the red sync momentary switch under the battery cover and connect to a remote switch to solve the daily ladder problem. The empty battery problem is solved by connecting wires to the battery joints and power the Wiimote via an AC adaptor or the USB port on the PC.
This modification requires opening and modifying your Wiimote all are done at your own risk. When you remove a sticker that covers one of the screws you will void your warrantee.
The Sync button modification is relatively easy and can be done independently or the remote powering modification if you desire.
Contents |
Opening the Wiimote remote controller
- Open the battery cover and remove the batteries.
- Four screws are visible; 2 at the rear of the Wiimote, the third and fourth one are located under the (now removed) batteries. The fourth screw is covered with a sticker.
- Put the Wiimote on the table, the buttons facing the table.
- With a No. 4 TORX screwdriver, also known as a 'star screwdriver' or 'star bit' remove the 4 screws. Put them in a safe place.
- Carefully lift the bottom of the Wiimote. Start at the rear end. The front side, near the camera does not disassemble. On the the front side of the Wiimote cover 2 clips are attached that hold the bottom in place. Applying force the wrong way will break off the clips.
- Lift up the rear side a little bit then stick a blunt, round tipped, thin table knife sideways between the bottom and the cover to release the clip. Carefully move the knife from the rear to the front until the bottom and cover separate on that side.
- Do the same on the other side and keep the bottom and cover together to prevent pieces falling out. Put the Wiimote on the table, the cover facing the table and and then lift off the bottom. In this way the buttons, speaker and rubber pieces will stay in place.
- To reassemble the Wii, adjustable joint pliers may be useful to press the clips together a bit while pressing the bottom and cover together:
- Whatever happens during the opening of the Wiimote, nothing to worry if the clips break off and/or the buttons fall on the table. It's easy to reassemble and two drops of glue in the final stage of the project will solve the missing clips problem. We use a Wiimote without clips.
- So, on the table lies the cover, buttons, the speaker, plastic and rubber stuff. Here are some pictures to show the inside. The two pictures below are taken from another Wiimote than all other pictures of the Wiimote's inside.
Remote control the red sync button
- To make the sync button and the powering of the Wiimote external, you need the following materials:
- 10 meters (large classroom) of thin flexible 4 wire cable. Mine has 4 colors: red (+ 3 Volt), blue (- 3 Volt), green and yellow (sync switch).
- 1 momentary switch for the sync button
- 1 on-off switch for the battery power. This switch seemed unnecessary in later prototypes. If necessary, this switch can be omitted.
- An enclosure. We found a plastic box of 5 x 7,5 cm.
- An AC power adaptor or an USB cable. They are not in the picture and will be discussed below when we power the Wiimote remotely.
- The electronic parts to regulate the power are also not in the picture and will be discussed below.
- This is the circuit side of the Wii's printed circuit board. The location of the switch and the 4 joints can be seen, as well as the 2 places where the + and the - of the battery connections are soldered on the print. Enlarge the picture to study details, texts and symbols.
- In the rear side of the Wiimote, drill 3 holes with a 2 mm drill. Enlarge the middle hole to the diameter of the cable. See pictures for details.
- Our middle hole is not exatcly in the middle. Not on purpose, just Lack of precision. You can do better.
- Enlarge the hole in the middle with a (Diameter of cable)mm. drill (ours was 3.2 mm.) so the 4 wire cable fits neatly in the hole. Later on you can glue the cable to the plastic if necessary.
- With a cutter, remove material so the wires can be bend (see picture below).
- With the side of your soldering iron, 'cut' the cable insulation. This is to prevent accidental damaging of the insulation of the four wires. 'Cut' about 20 (twenty) centimeters of insulation. In case it's impossible to cut such a length in one go, do it in stages.
- Put the 4 wires trough the middle hole and gently press the cable through the hole. Bend the yellow and green pair and the red and blue pair according to the picture. Please bear in mind that there is very little room in the Wiimote. No need to trim the wires yet.
- In the Wiimote cover, remove the thin white plastic as shown (black '<') to make room for the wires.
- Solder the four wires. Solder as quickly as possible in order to prevent overheating of the printed circuit board, components or other soldered joints. The 2 joints on the battery need a bit more time in heating than the two joints on the switch. If you do not trust yourself here; no sweat. You have done everything. Ask someone with a bit more experience. There are many and she/he will do this job in 5 minutes. Or, an even better alternative, rise early, find an old radio in the trash on the streets, open it, practice on the printed circuit board inside and become an expert yourself.
This is the result:
The 4 wires are connected and bend in such a way that the cover can be replaced.
- Put a couple of matches on the table and put the Wiimote cover (buttons facing the table but not resting on the table because of the matches) and carefully put the Wiimote bottom with the printed circuit board over the cover and gently press the two together. Some fiddling with the wires may be necessary because the is hardly any room for the wires. When you have replaced the cover and all fits well without force, use a couple of rubber bands to hold the parts together for the time being.
- Insert the two batteries. Do not use the battery cover for now.
Testing Before replacing the 4 screws, make sure everything is still working inside the Wiimote and at the other end of the cable. Test as follows:
- Test the Wiimote. Are all buttons on the cover still functioning? Is the sync button still functioning?
- Test the connections to the sync button. At the other end of the 10 meter cable, strip a bit of the insulation of the green and yellow wire and, just for testing, solder the two contacts of the momentary switch on them. Press the switch. The four leds should flash.
- Test the connections to the batteries. Strip the red and blue wire and, using a voltmeter, check if you find about 3 Volts on the wires.
- Final test with the Wiimote and the PC. Is everything still functioning as before?
- Find the 4 screws, insert and tighten them (not too hard!). Test again if everything functions as before. The red sync switch should still work as normal and all the buttons on the Wiimote should function as well. If you wish, you can use two drops of glue to replace the 2 plastic pieces that came off during the disassembling of the Wiimote. It's not necessary.
Have a drink and congratulate yourself. The toughest part is over. The rest is a piece of cake.
Powering the Wiimote
To remotely power the Wiimote you can choose two solutions: an AC power adapter or powering the Wiimote via USB. The Wiimote needs 3 Volts DC (Direct Current) or less. Alkaline batteries provide about 1,5 Volt. Nickel cadmium or NiMh cells provide 1,2 Volt. It is critical not to overpower the Wiimote, so we use a voltage regulator to keep the voltage at 2.85 volts. This makes the use of the power source less critical. An AC adapter, laying around in the school or at someone's home, supplying 3 to 7 Volts is fine. The voltage regulator will bring down the voltage to 2,85 Volts. You can also use the power that is available via the USB connectors on your PC. USB connectors supply 5 Volts. The voltage regulator will bring it down to 2,85 volts. When working on the power supply we also make a warning light, indicating the Wiimote is powered. We use a red 3 volt LED.
Powering the Wiimote via USB
When your PC has more USB ports, or you found an USB PCI card with multiple ports, you can use one of them to power the Wiimote. An USB port has + 5 volt to power small USB devices that use little current. Here is the pin configuration of an USB connector:
- Find an old USB cable from a broken device, or an USB extension cable, cut off the 'other' end and strip the insulation. Here is an example:
- The 4 wires, red, black, white and green can be seen, as well as the shielding that protects the data transmission from electromagnetic radiation. The shielding is not needed in this project since we only use the power wires.
ingredients to power the Wiimote via USB
Explanation of the red numbers in picture:
- A polar capacitor of 100 µF (micro Fahrrad). A capacitor is a device that can hold and release current. Polar means it has a + and a - side. This is the symbol for the 2 polar capacitors we use:
- A voltage regulator. It's an electronic part that can bring a high voltage down to a lower value. This is the symbol:
- A polar capacitor of 10 µF. See above for details.
- A resistor of 60 Ohm. Because of the voltage of 2,85 Volts you cannot directly connect the LED. The resistor, set in series with the LED, reduces the current the LED gets. This is the symbol of a resistor:
- A plain ordinary 1,5 Volt red LED. You know the symbol from the IR-Pen.
- A piece of printed circuit board. It will b eused to solder the components and wires on. We bought a piece of 5 x 10 centimeter. Enough for about 5 classrooms.
In the shop they will ask you: "What voltage?". Answer:"Above 20 volts or so, whatever you got if it's small". The same goes for the other capacitor.
We use an LM 1117DT 285, manufactured by National Semiconductor. It can bring voltages not higher than 7 Volt down to 2.85 Volt. Get the data sheet from your voltage regulator manufacturer for all details including wiring diagrams.
Explanation of the white numbers at the LM1117DT 285 in the picture:
- Reference. Connects to - (minus or 'ground'). Both the minuses from the USB connector and the Wiimote battery are connected to this pin.
- Out. Connects to the Wiimote with + 2.85 Volts. The same 'pin' can be found on top of the regulator, so it has the same number. We will use that 'pin' to facilitate soldering and to fix the regulator on a piece of printed circuit board.
- In. This pin connects to the red + 5 Volt wire on the USB cable.
NOTICE: The LM1117DT 285 is chosen because it needs no adjustments or extra parts and it makes the voltage supplied to the Wiimote less critical.
- There are many alternatives for the LM1117 DT285 voltage regulator. You could use a adjustable voltage regulator, or two resistors of fixed values, or one adjustable resistor, but then you have to find the correct values of the resistors yourself and, IMHO, you end up with a poor design that's not stable enough for use in schools.
Electronic circuit
And this is the plan:
- Make a drawing on how the components will be soldered on the pc board
- Prepare the pc board
- Solder the components on the board
- Prepare the enclosure, i.e. drill holes etc.
- Prepare switches, LED and USB- and Wiimote cables
- Solder everything except the power connection to the Wii.
- Test the circuit
- Connect the power to the Wii.
- Test again.
Here we go, this is the execution:
- As you can see we also put the 60 Ohm resistor for the LED on the PC board.
- With a 4 mm. drill, by hand the copper is removed and with a sharp cutter the remains are removed.
- With a pair of tweezers and a rubber band the voltage regulator is held in position, ready for soldering.
- The capacitors and the LED are mounted on the other side of the pc-board.
- ERROR! The 60 ohm resistor is not soldered on the pc board. You can see the resistor in the picture 'enclosure.jpg' below.
- The LED is wired to the PC board. Everything is ready to connect the last parts to the board: the USB cable and wires, the on/off switch and, finally, the Wii.
- Strip about 10 cm. of the USB's cable insulation, remove the electromagnetic shielding and the cotton. Cut short the green and white wire and insulate the ends with pieces of heat shrinkable tube to prevent short circuits. Push back the insulation of the cable to the wires ending to cover the protruding shield and cotton. It should look like this: the white line in the picture indicates where the shield and cotton end.
- Prepare the enclosure by drilling holes, sawing and filing until you end up like this:
Before we start soldering the wires we make a knot in the cable coming from the Wiimote and the USB connector cable. You can also use a tie-wrap, kit, or anything else to make a pull reliever.
- Start with the cable coming from the Wiimote. Solder the yellow and green wires to the momentary switch. For the last time (hopefully) insert the batteries in the Wiimote and test the momentary switch. After testing, do not forget to remove the batteries!
- Take the USB cable. Solder the red + (plus) wire on one pin of the on/off switch. Solder a red wire from the other pin of the on/off switch to the pc board on a copper lane of pin 3 of the voltage regulator.
- Solder the USB cable's black - (minus) wire to a ground copper lane (where the minuses of the capacitors are connected, for example).
- Meticulously inspect the copper side of the printed circuit board for solder spikes and short circuits between the copper lanes. Remove them with a sharp knife, screwdriver, pin, etcetera.
- TEST!! Put the switch to its 'off' position, Connect the USB cable to the USB entrance of the PC. Set the switch to 'ON'. The LED should light up.
If not, switch off and check everything. If the LED lights up and you have a multimeter, check the output voltage. It shoudl be 2,85 volts.
- Connect the Wiimote's black - (minus) wire to the copper lane of the - of the capacitors.
- Connect the Wiimote's red + (plus) wire to the copper lane of pin 2 of the voltage regulator.
- For the last time, inspect the copper side of the printed circuit board for solder spikes and short circuits between the copper lanes.
- Piece it all together. With us it looks like:
- If necessary, put some kit on the LED, USB and Wiimote wires. Close the cover and put some rubber bands around it.
- Test 'everything' possible before attaching the four screws of the enclosure.
Powering the Wiimote via an AC adapter
Maybe its an idea to first read the previous section. Almost certainly it will convince you that powering the Wiimote via a AC to DC converter is a piece of cake. In fact the only thing you have to do is replace the USB cable for an AC to DC adapter. However, to play everything on the safe side, here are our guidelines:
- Find an AC to DC power adapter. AC means Alternating Current. The power adapter you find will have an input of 110 to 230 volt AC. It will convert this to DC.
- DC means Direct Current; what batteries supply. The Adapter you find must have a DC power of 3 to 6 Volt. We strongly suggest you not to use an AC adaptor that gives more than 6 Volt DC. The power regulator is specified to function up to 7 volts, but we want to stay on the safe side. So find a AC to DC adaptor that gives between 3 and 6 Volt.
- Out of the adaptor comes a cable, consisting of 2 wires: the + and the -. It's up to you to find out what the + and the - is. Here are some methods.
- Find a multimeter to determine + and -
- Find a resistor of about 200 Ohm. Connect the one wire of the resistor to the + of the LED. Connect the - of the LED and the other wire of the resistor to the power adaptors wires. If the LED lights up, the + of the LED corresponds to the + of the wire. If the LED does not light up, reverse polarity and you have found the + and the minus of the wires of the AC to DC adaptor. Mark them by putting a knot in the + wire.
- Return to the USB setup and connect your knotted wire to the + on the printed circuit board.
- Connect the - likewise.
- Proceed as in the USB setup, i.e. test, test, and test again.
