It is perfect for car camping trips, tailgating,  the beach, and basically anything not near a power source (including if the power goes out).  I got an 88L igloo cooler for mine but any will do.

I chose to purchase most of my components online, starting with some 5.25 Boss marine speakers.  I thought that mounting to the cooler was going to be difficult but after bending the supplied clips and inserting them behind the first layer of plastic it turned out extremely solid and easy.

The clip acts as a nut and washer behind the plastic.

Then I was able to mount the head unit and battery. I also threw in a 400w power inverter (far right) for small jobs and I’ll probably add a larger one later for larger tv’s etc. Above the inverter is a small battery charger and maintainer to keep the 115AH deep cycle marine battery topped off when at home.  A simple switch panel at the bottom controls the charger, stereo and other components to the system.

Still to come is the marine subwoofer and amp, some 12v cigarette sockets and a solution to control the stereo via remote when the lid is closed. Just in case you were wondering why not mount the head unit through the cooler, I will be mainly using this car camping and It needs to be able to survive a heavy rain with no problems.

———————————–Update March 2010———————————–

This is the setup that I used for ~8 months. I have yet to find a good price on a 200-400 watt amplifier so I just wired the subwoofer as a rear speaker for now.

From West Marine I purchased a waterproof splash cover for the head unit. That allowed me to mount the stereo on the back side of the cooler for easy access. I lengthened the wires so that I can keep the sensor in the front.

The view from the front did not change. There is enough room on the front to move the current speakers to the sides and replace them with larger ones.

The cover is translucent and allows you to view the display easily while keeping any sand/moisture/water off.

Cover up.

The disconnect for the IR sensor that I moved to the front. This way the faceplate can be removed if needed without cutting any wires.

Here is the old “caddy” I used to help me cart the cooler around. It was made out of junk parts and was meant to be temporary but ended up being used more than I liked. It slid off and was ugly plus it was unstable.

So, I took the wheels off and made a K.I.S.S. solution. It only required ~$5 in bolts and brackets from the local hardware store. I reused the wheels.

Each wheel has its own bearing and is just bolted directly to the 2×4 with a washer to add spacing. The main bolt goes in through the drain plug and holds the 2×4 up to the cooler while the brackets take most of the weight. This ended up working even better than I had thought.

On the inside is a nut JB Welded to a washer which is glued to the cooler.  When the wheels are removed you can put the cap back on the drain and no one would be the wiser.

First trial run. Very strong, doesn’t wobble or feel loose in any way. I can even stand on this end of the cooler (which also has the ~45lb battery) and it feels very sturdy. A nice handle on the end of the nut will have to be added in the future for ease of use. And perhaps a coat or two of paint.

View from the front. The wheels will probably stay on when no one will be sitting on it and on the beach, but can easily be removed just by unscrewing the one bolt going through the drain plug.

And from the back. Also the placement of the wheels give me more clearance when I pick up the handle to tote it along. That should be nice in the sand our outdoors in high grass/dirt.

At the beach, even in very strong winds it can be heard and sounds great (with appropriate volume levels considering any neighbors). Ipod on top plugged into stereo’s aux in.

Whats next?
- Tidy up the wiring and mount everything securely
- Fuse block and kill switch
- Switches, volt meter, 12v cigarette plugs, amplifier
- Cover for inside with mounted switches and volt meter
- Storage for cables
-Padded cushion top
- Cooling for stereo and the future amp
- Wheel(s) for transportation

Feel free to leave any questions in the comments or just Contact Me.

The barrel is actually rifled just like you would see inside a rifle. It was purchased several years ago by me from www.SpudTech.com which has some great products. The chamber size was calculated around the size of the barrel since I already owned it.  Using various online calculators I determined the needed size of the chamber and metering tube for the propane.

A regular pc fan is used inside the chamber to vent out the burnt air after each shot and to circulate the propane to evenly mix it. I did not have this setup the first day I used it, so comparing with and without, I would highly recommend a fan inside. Also you can see the pcb board that creates 8 spark gaps for  the stun gun. On the right side is a 3″ piece of pvc pipe which holds the propane tank and a project box from radioshack.  On top is the metering tube for the propane injection. This propane injected stun gun / taser fired potato cannon is quite efficient.  3 bags of potatoes and 0 misfires.

Here is a side shot of the chamber with the barrel removed. To fire the gun you attach the barrel (screw it on) insert potato in the end of the barrel and pack it down to the bottom of the barrel where it meets the chamber. Next you turn on the fan to vent the chamber and put the cap on the end of the chamber to seal it off. Turn the valve on the propane tank on and watch the pressure gauge as it pressurizes the hose. After turning the first valve to fill the metering tube wait for the pressure gauge to climb back up to about 75-80 psi (propane tank supplies 90psi) then turn off the valve. Now turn the chamber fan back on and release the propane into the chamber using the valve on the other end of the metering tube. Arm the ignition by turning on the switch on the far left and you are ready to fire.

I am in the process of making a chronograph to measure the muzzle velocity of the potato cannon. This prototype failed to work at the speeds the potato(s) was going.

Basically it consists of two photo resistors one foot apart. As the potato passes by it blocks light and that reading is calculated by an arduino microcontroller and fed back to my laptop.

A simple chair with some plywood served as the base for the chronograph with another piece of plywood to keep direct sun off of the device.

After three shots the chronograph never got a reading so shooting the plywood let out some frustration :) . Before first shot.

After the first shot. The rifling causes the potato to come out a little up and left. However, it stays very very straight after that due to the spinning caused by the rifling.

Second shot knocked everything down and went right through the 1/4″ plywood at a distance of ~20ft.

Back side of second shot and front side of third shot.

After only a handful of shots the plywood is decimated.

Sample video showing plywood destruction and brief operation description.

]]> http://www.Addictronics.com/projects/portable-potato-cannon/feed 1 http://www.Addictronics.com/projects/microcontroller-launcher http://www.Addictronics.com/projects/microcontroller-launcher#comments Thu, 13 Nov 2008 05:57:54 +0000 admin http://www.Addictronics.com/?p=579 EDIT: Made it to the front page of HAD http://hackaday.com/2008/11/15/microcontroller-fireworks-launcher/

So on a slight upgrade from my last launcher I made a new model rocket/Fireworks launcher using an Arduino microcontroller . This project was inspired by this wireless fireworks controller and this microcontroller rocket launcher . I really did not want to dedicate my launch device to any one specific role since celebrations are far apart and model rockets are somewhere near the middle of my list of hobbies.  By combining the two different devices together I was able to achieve what I wanted.  Most of my original drawings are found here…

I was going to use the ATmega32 microcontroller because of its quantity of digital I/O lines but settled on using an Arduino Diecimila for prototyping and RBBB for implementation. Keeping things simplistic but still allowing a workable user interface I decided on only using 4 buttons and 2 switches.

• Power Switch:
• Turning the device on and off.
• Key Switch: Activating the launch screen and final authentication method before launch.
• Left/Right Launch Buttons: Menu Navigation, login acceptance and launch.
• Up/Down buttons: More menu navigation.

The ATmega168 only has 14 digital I/O lines and I will be requiring at least 1 for each switch and launch terminal.  Two 8-bit shift registers give me 16 terminals and are super nice because in order to operate both you only have to sacrifice Three pins. Here are some things I wanted to include

• Startup melody
• Password authentication
• Key Switch
• Ability to change launch configuration such as delay and patterns.
• Screen for pattern selection and other settings.

Here is the finished prototype. Basically this is just a proof of concept and also it allowed me to finish the software prior to installation. You can see the black 16pin shift registers each broken out to LED segments. The yellow chips are 330 ohm resistors.

I finished the transistor board after lots of soldering. Each output from the shift registers are connected to the Base of the Transistor through a 1k resistor and each pin has a pull-down resistor as well. Instead of using one power source, the terminals will be broken up into four power sources. Two 9 volt batteries in series will feed each section of 4 terminals. Eight batteries for the launch system and two more for powering the microcontroller, LCD screen, LED’s and etc. To help take the initial shock current off of the 9v batteries each of the four sections has a 4700uf cap. The smaller cap is part of the 5v regulator system for all the controls.

Using an old floppy cable I connected the transistor board to the Arduino RBBB. And then some more for connecting up the switches, buzzer, led’s and LCD screen. All that is next is to wire up the terminals to the transistor board and then mount it all in its case.

Well wire that up and get some more batteries :)

After acquiring the batteries and finishing up the wiring I started looking for a case. I knew that I wanted something pelican-esk. I found this Plano waterproof case at Academy Sports an everything fits inside perfectly. The next problem was what to use for the lid to mount the switches to. Three walks around my house landed me with some plywood, Plexiglas and a clipboard. The clipboard almost fit to begin with so I chose to use it. After some hot glue here is the result.

I had to recess the top piece down some for the red arming switch to clear the case lid. I really like the looks of how this turned out.

The launcher booted up and armed, ready for launch. I should probably mention the two momentary push button switches to the right of the LCD screen. I used some felt with sticky on the back to cover them up and still show their location. I would probably use larger push buttons that were mountable if I had to do this over again.  Also each launch button  (bottom left and right) have built in blue LED’s which didn’t show up in this picture.

Steps to get to the launch screen include:

• Turning the power on
• Entering in launch code.
  • Press and holding both launch buttons to verify code
  • If code is wrong it notifies the user and reboots
• Selecting the launch array which include
  • Every terminal
  • Every odd terminal
  • Every even terminal
  • Terminal #1 only
  • Every terminal with a 1sec delay between
• Then inserting the key and turning it to the on position.
  • This arms the system and turns on a relay which connects the battery packs to the transistor board.
  • Also when armed the launch buttons light up bright blue.
• Pressing both launch buttons simultaneously.

Inside the case the first thing to notice is the battery array. Two for each terminal and two for the launch system. Hot glue was mainly used to hold things together but some other reinforcement will be added before this sees field use.  A short test of each terminal and all buttons and this is ready to see its first rocket or firework.

Coming this New Years will be another video of it in action but here is a short demonstration video.

Microcontroller Rocket/Firework Launcher from Adam on Vimeo.

Things to Consider
If I were going to do this again I would probably try to use a different power source. I think a rechargeable alarm battery would be easy to integrate and also would allow recharging. As I said before I would also use different up down buttons next to the lcd and try to trim the edges of the lcd with something more professional looking.

I have some Ideas of things I will add or change such as more launch arrays and a login password that is changeable via the device and not software set. Adding a security measure of having to press the launch buttons within a certain amount of each other would be doable and make accidental launch less likely.

One thing that I am planning on adding for sure is some type of remote, probably wired, to set off the rocket or fireworks from an even further distance. I’m thinking of using a project box and telephone cord for this but if you can think of something better let me know!

If you would like the code or schematics email me and I will send them to you. Thanks

• Flight Computer x2
• Cutdown Mechanism x2
• Aileron Servos x2
• Temperature Sensors x3
• Altimeter
• Compass
• GPS
• Packet Modem x2
• Digital Camera
• Accelerometer
• Battery
• FM Beeping Tracker

These are the systems that will control the glider as of now. The list shouldn’t change unless I come up with a better idea later on into the build. The current components that I already have are:

• Prototype Flight Computer
• Camera
• GPS
• Both Aileron Servos
• All Temperature Sensors.

I am using Arduino micro controllers to basically run the glider. Since there are so many components and calculations that have to occur in real time, I plan on having two for redundancy and processing power. To prototype I am using the Arduino Diecimila because of its easy usb interface. For actual glider use, two Arduino Nano’s will be used because of their tiny footprint and weight. The I/O pins are the same between the Diecimila and the Nano which will make the swap over very easy. Cost (Diecimila) $35.00

Arduino Nano

The camera was purchased off of Ebay with a broken LCD screen… I am stripping all of the cover and excess weight off of the components anyway so this makes no difference. The less the glider weighs the better. Cost $20.00 Not any ordinary GPS unit can be used for these high altitude trips. Laws are in place that restrict gps manufacturers from making units that will work over 60,000ft or 1,000mph. I was however able to find the Garmin 35 Series, that were made before the laws became active. It uses a serial connection to talk with the Arduino. Cost $25.00

I actually had a friend that I traded some component for two super sub-micro 6g servo motors. Cost $0.00

The temperature sensors I decided to use are the 1 wire type and are free samples from Maxim-ic. Cost $0.00

Glider Types:
One of the things that took the longest for me to decide was what type/style glider do I want to make? Having no prior aeronautics or RC Glider/Plane experience, I looked at all possibilities. Looking through articles and talking to people on forums is where I gained most my knowledge. I had to figure out if I wanted a glider that A: Stays in the air the longest. or B: Glides the furthest. I decided to go with B since I may eventually have the glider land at a far away location. It would be very interesting to have it fly X number of miles and to take pictures of its journey. The biggest issues that I have to think about when deciding which glider type to use are weight and strength. I need to make this entire project as light as possible as to meet FAA regulations for amateur ballooning. Looking at the results from Mark I, I found that great speeds and G forces will occur during initial cut down and pullout. Here are the designs I have been considering and why I am considering them.

Glider Types Part II:
(These images were taken from Google and I am in no way affiliated with them or their takers)

I found this military glider and really liked the wing design. It looks very stable and likely to give a very good glide ratio. Although that was before I knew what happens when you take a glider over its maximum speed.

That video is even more appropriate for this design. I found this one before I saw that video also. The things I liked about this design is that it has room upfront for the electronic components and could be controlled by 1 vertical servo and 2 horizontal aileron servos. Which is better for redundancy.

I found this RC Glider and at first didn’t like the V tail. However, by using the V tail I can eliminate an entire servo and only use 2 for controlling the glider, this is still redundant if one decides to fail. The streamlined fuselage would have less wind resistance and the large wingspan would offer a better glide slope. The only downside is that I don’t think there is enough room for some of my larger components.

I must have spent at least an hour looking this single photo over. It is a great collection of RC Gliders and looks tremendously fun. I never expected to find them as large as shown here. I would love to build one as large as the tallest ones you see but don’t know if I can keep the weight down and strength up.

Finally I found the one I am gong to use. It can be made strong enough, light enough, and still have room for all components. Unless some other better design pops out of the wood work, this is the one. I doubt that any glider kit out there is strong enough for my needs so it is inevitable that I will have to make it from scratch. Which suits me just fine!

So now onto the components to go into the glider. Here is a small list of the main ones.

• Microcontrollers
• Camera
• Redundant Cutdown Controllers
• Temperature Gauges
• GPS
• Communications
• Glider Controls

One of the main things I want to get back from this project is high resolution pictures of the earth from extreme heights. I was planning on using an old 4mp digital camera to do this but an ebay search and 25 dollars later I landed myself a nice Cannon 8mp digital camera complete with broken lcd.

Most gps manufactures have restrictions that are in place to keep people from using the receivers for guided missiles and such. They fail to work above 60,000 ft or over 1,000 mph. Now some manufactures take this request as an OR statement. Either shutoff above 60,000ft OR over 1,000mph not both. I was able to find one that was made before these regulations took effect. It is widely used by amateur balloonist. The Garmin 35 series.

So after a quick ebay search I found one for 20 bucks.. sweet. After stripping off the weatherproof outer shell here is what you’ve got.

The gps ended up having rs232 outputs and the Arduino accepts TTL level serial.. So a max232 circuit later and we are all set. The camera is extremely light after removing the cover and batteries and there was also quite a bit of change on the gps once its protective shell was gone.

So now there is only one main component left to find. Communications

Now the glider link above used a packet modem and the Payload link above used HAM radio.. Since I don’t have any ham radio equipment let alone a license, I think I’ll stick with a packet modem.

Oh yeah. Almost forgot that I am broke and in college (typical). Off to find a cheap way out. Wala, Meet the Motorola C168i. This 9 dollar phone with 25 dollar airtime will give me 3 months or ~150 text/SMS messages of use. Also it can be refilled whenever I decide to launch again. One downside, GSM cell coverage typically cuts out ~10,000 ft. but then again it is going to have to come down eventually.. It absolutely amazed me how easy it was to interface. The headphone jack is also a TTL serial port.

And next to the other components with a 3″ cardboard tube in the background (probably going to be the (mold for the) fuselage.

Ok so now the GPS is ready to integrate and so is the Cell phone. I put off working on the camera any more because I didn’t know what all I wanted it to do. I finally came up with it taking pictures every ~20 seconds and videos at various moments (launch, cutaway, landing). I used some bent wire to make sure I had the correct traces located and proceeded to remove the plastic cover and dome switches.

Next I securely attached and soldered the wires to the camera.

Here is a picture of the really bare bones board (RBBB) Arduino Kit from Modern Device. They are so much smaller than the Diecimila.

I used female headers on top instead of male headers on bottom. this will allow me to directly connect them into a breakout board im making from scratch.

Three of these will be in the glider and here are their individual functions.

Flight MC1:

• GPS data
• Temperature sensors
• Pitot/Static Tube

Flight MC2:

• Camera Timer
• Camera Servo controls
• Swap camera between video and picture modes
• Reset A1 or A3 if they fail to check in within a specified time

Flight MC3:

• Servo Controls (for glider)
• Flight Calculations.
• Cutdown Controls 1 and 2
• Ground Communications
• Chute Release

And here is the flight computer and other major components awaiting code testing. I just need to finish wiring it up and am still waiting for the third flight computer (freeduino). Once that has arrived I’ll start testing some code out to make sure that I can get every system working individually before I put it all together.

Project Still Underway! (Stay Posted)
- Due to insufficient funds this project is being put on hiatus until I am able to pick it back up again.

I decided to put the assembly inside a small case I have for portability. Using the sound amplifier out of an old set of pc speakers, I am able to have a stereo setup with two hard drives. The right channel hdd speaker has a single platter and the left channel has 3. It was interesting to watch how the different sized r/w heads responded to different frequencies and volume levels.

It is a lot easier to make this work than you are probably thinking. It is as easy as hooking up the speaker or headphone cables from your computer straight to the two wires that move the read/write head back and fourth. With the read/write arms having coiled wire between two strong magnets (opposite side of the read/write heads), they act just like speakers do. Just less efficient. Sound is created by the arm moving back and fourth, that’s it, no movement of the platter at all. After looking at one of my hard drives I easily traced the two wires that controlled the arm. They are pin’s 5 and 6 in this picture.

Those pins continue on through the hard drive case to the circuitry underneath. I pulled off the original circuit board and cut down a floppy drive connector to easily connect to the hard drive. Cutting off all of the wires except for pins 5 and 6 was my last step in preparing the hard drive, those wires went to the positive and negative from the pc speaker amp.

The triple platter drive produces quite a bit more sound but is less responsive. Since it is getting the same power as the other arm but weighs more that does make sense. The tricky part was to get the arm out from the platters so that I could bend the heads to prevent vibrations.

The single platter arm moves more through songs and other tone tests. However, it produces maybe 65% the amount of sound that the larger arm does. Neither arm preform well with deep sounds. High tones or what I call 8-bit tunes sound great, I’d dare say better than regular speakers.

The single platter drive is on the left and the triple platter is on the right. It is amazing to me how fingerprints seem to magically appear on open hard drives.

Here is the triple platter hard drive playing a RadioHead Nude hardware remix (original video after mine)

Big Ideas (don’t get any) from James Houston on Vimeo.

Now that the summer months are approaching, I started monitoring the temperatures more closely. I am not happy at all with the temps that the hard drives are reporting back but they really do not surprise me. A change is in order and I have decided to move them out from the top of the attic to down next to the central heating and air unit.

Okay, I might have been able to take pictures of the building process but just didn’t. Here is the completed unit in place. Each 2×4 will support a shelf that will have a pc on it. One shelf per pc, I went ahead and made 4 shelves for future expansion but for now the extra shelf with hold the batter backup and network switch. You might recognize the black 6 fan holder from the Water Cabinet project, probably because that is where I got it from. I took the 12v inverter you see sitting on the bottom shelf and cut the end off of it to power the fans, it works very well and provides plenty of ventilation for the case.

I went ahead and added the first shelf, On it I have screwed down the motherboard, power supply, floppy drive, and hard drive of the web server. It is a 600mhz 382mb 40gig Pentium III system.

Inside the webserver before.

The second shelf is the 1ghz 256mb 750gig Pentium III File Server. I use it to backup my music, dvd and data disks.

Inside the fileserver before the case upgrade.

This case is extremely heavy duty, I really do not remember where I got it but it has held no less than 5 different pc’s since I’ve owned it.

Using some cardboard and more duct tape I made a nice little duct for the air to flow directly onto the processor.

My goal was to try and get as much airflow over the hard drives and processor as I could. The side duct handled the processor but I still needed to work on the airflow for the harddrives. By adding additional slots in the front I could get greater air flow.

Behind the slits I cut a hole in front of the harddrives. Also I put some duct tape over the existing holes so that all air is directed over the harddrives. This lowered temperatures by about 8deg F.

The rack so far. Notice the duct tape for an extra air-tight seal.

Finally on the top shelf is the Firewall. It is a 300mhz 128mb 10gig Pentium II. I installed Smoothwall on it and have had no problems. Not long ago I “upgraded” it to the 10 gig hard drive for more cache space, which noticeably improves web browsing. The floppy drive is used for setting backups and worked great when I decided to change hard drive size. Smoothwall can be installed on a 1 gig drive and I would recommend installing it on a Compact Flash drive or SSD because of the reduced power consumption. I will probably end up going that route later on.

Inside the firewall before the case change.

Notice how I zip-tied two Pentium II heat sinks together to try and keep the processor as cool as possible.

Other side.

The back of the firewall had a spot for a 90mm fan but I put some duct tape over it to redirect the air flow as best I could. Same with the PCI slots.

I went ahead and set the switch in the bottom shelf and still need to attach the back and top before I can slide the filter in.

The final product. I used a 20″x30″x1″ Filter to keep dust and other particles out, It should be easy to clean and this system is a prototype of sorts for me to try this idea out. You can see one cable coming out of the front in this picture but it is soon to be moved to the small hole I have in the bottom shelf for cables.

• Min-ITX Motherboard 1.8ghz
• Mini power supply 12v input
• 1gb ram
• 40gb laptop hard drive
• hard drive adapter
• Wireless card

My first mission was to find something to house all of this in and here is what I found.

So I went out and bought it.

It is a 2 pistol gun case from Academy Sports. The mini-itx fits in the bottom perfectly, and there is room to plug in usb devices/ monitor cable/ audio cables without cutting any holes. Also the lid is about an inch thick with the foam. The first thing that I did was to cut a hole in it for the touchscreen monitor and it looks great!

And here it is with the motherboard sitting in its place.

Since the mouse is integrated with the monitor all I lack is a keyboard to get this project rolling. A quick search revealed this, A mini usb keyboard that is only 11.7 inches wide and 6 inches deep. Its perfect!

I actually ended up rotating the motherboard because it fits better this way and the ventilation will be better as well. You can see what I had to do with all of the slack from all of the cables. Everything is mounted with super sticky Velcro and lots of it.

Once the first layer of foam is removed from the lid you can see the relocated speaker and the mounted gps unit. I found some cable organizers that have very sticky pads on them and work great I just need more of them.. The Velcro works extremely well for mounting everything. It lets everything move a little and dampens vibrations also it allows everything to be removed if need be.

Okay, I got the keyboard in and it is almost insane how well it fits. If the keyboard was 1/8th of an inch wider or more narrow, it wouldn’t fit. I had to take the bottom off of they keyboard so that it would lay down flat and not hit the screen when the lid is closed. Next I added two supports to hold up the keyboard and help strengthen the case. I used the existing screws and holes for the handle to mount it on the front side and some Velcro to mount the backside of the supports. The Velcro allows the supports to move and give which is perfect since the case isn’t super rigid. Also the Velcro eliminates the need to add more holes into the case. Now I just need to fill the holes on the top and bottom of the keyboard.

I used some more of the foam that came with the case to fill the gaps on the top and bottom of the keyboard, To keep the foam from being pushed down to far i added strips of aluminum with sticky foam tape behind it to hold up the foam inserts. Also I added two usb ports and the power plug above the keyboard. The wire you see holding up the lid is temporary, I still haven’t found a way to keep the lid from opening to far without adding any holes to the case.

I left a hole on the bottom left hand side of the keyboard and the top left side of the keyboard for airflow. There is a fan you can see in one of the previous pictures that blows air out above the left hand side of the keyboard. This allows air to circulate through the cpu, ram and other heatsinks before leaving the case. In this picture I am running a Folding at Home (F@H) test to check the stability of this system. If it doesn’t overheat after a day of running this then it is stable enough for me. The white wire is an Ethernet wire since i haven’t bought a usb wifi card for it yet. I already have the bluetooth dongle installed and that allows me to use a bluetooth keyboard or mouse instead of the built in ones, also I can access the internet through my cellphone via bluetooth. The usb GPS module is removed because I do not know if it will get enough signal from its position inside the lid. I will update that as soon as I am able to test it more.

 Next Steps: Figure out GPS situation, Install usb wifi adapter, Find something to cover the foam with to keep dirt out, Make cigarette adapter for in-car use.

There are quite a lot of things to do with an old NES controller but none are perhaps as useful as an optical mouse. The first step was to buy an old NES mouse off of ebay. I got this one for $3.

Once open, the controller is very simple on the inside.

At a local computer store that specializes in older computers parts I picked up a 3m joystick mouse. It has left, right and scroll-lock buttons but no scroll wheel.

After disassembling the mouse here is what I am left with in comparison to the NES controller.

I cut off the original circuitry that was behind the d-pad. Then I scraped off the coating over the copper trace on the pcb board. On the mouse I cut off its 3 buttons and soldered the wires directly to the traces. So now the controls are Down = left click, Up = right click, and Left = scroll lock. I also added some foam to make the whole thing feel solid.

And here is the mouse in action, you can see that left and right click are still left and right (or up and down on the controller). It works great actually.

This is the only hole I had to cut in the case, it is for the optical sensor. I just copied the hole that was in the old 3m mouse.

]]> http://www.Addictronics.com/projects/nintendo-optical-mouse/feed 4 http://www.Addictronics.com/projects/power-inverter http://www.Addictronics.com/projects/power-inverter#comments Wed, 12 Mar 2008 02:43:52 +0000 admin http://www.addictronics.com/projects/power-inverter About twenty seconds after testing my new 150watt,12v car power inverter, I knew something had to change. The built in fan was entirely too loud and I instantly came up with several ways of changing that.

• Put a resistor on the fan power to slow it down and make it quieter.
• Put a variable resistor so I could adjust the power level for better cooling.
• Get rid of the fan and see what happens.
• Add an external heat sink to take the heat load out of the case.

I finally decided on the latter of the choices as it is the quietest and safest combination. I figured that the fan was there for a reason and just getting rid of it would turn out to be a disaster. So my first step was to try and find a small heat sink that I could use to cool the inverter. Here is the location of the screw holding the inverter together.

Next I had to pry back four tabs that held the two sides together. I suggest using a knife for this task. And here is the case disassembled with the LED status light still glued to the lid. Also you can see the aluminum “heat sink” inside the case that the external heat sink will transfer from.

I found a heat sink lying around my room but it was still far to big so I hacked it down to size with my grinder.

Next I cut the leads holding on the fan, making sure to insulate them from each other afterwards.

My Dremmel tool is out of commission at the moment, so I had to use my grinder to murder the plastic case to allow the heat sink to pass through. Here is the final result.

After gluing the heat sink in and putting thermal paste heavily on both it and the small heat sink inside the case, I reattached both sides back together and pushed the heat sink hard in to make contact with the metal inside the case. The glue I used to hold in the heat sink was not dry yet so now it will be seated in the proper position.

Now that I have reached my destination (4hrs of driving) I can say that the heat sink is not near large enough to passively cool the inverter by itself. I am planning to re-insert the fan back into the casing, but adding a small resistor to knock it down from 12v to about 9 or even 7. Also I will add a small switch (PB or Toggle, I don’t know which yet) to allow the noisy fan to be turned off if it is powering small loads. My laptop charger says it only draws 65watts, and it is a 150watt inverter, so I had planned for it to not be under much of a load. I guess I was wrong.

One thing I learned that is good is that when the inverter overheats the beeper that I almost cutout will beep about once every five seconds. This informs the nearest passenger to either remove it or duck. When I get back to my workshop I’ll fix the known problems, hopefully not finding any more one the way home, and post some pictures later.

After reinstalling the fan I discovered that the heat sink I added now hits the top of the fan. This prevents the case from closing back together. My plan to fix that is to grind a notch off of that side of the heat sink.

I added an 100ohm resistor to the fan in order to shut it up some. It worked quite well and I decided not to put a switch since it is now quiet.

I also decided to help the now slower fan out by cutting down on air resistance. I carefully bent some of the capacitors out of the way, and rearranged how the LED wire bent into place. Then I cut out some of the plastic on either side of the case where the vents are and added some soft foam next to the fan to prevent a circulation inside the case. I have noticed a tremendous improvement in airflow and am quite happy with my hack.

It has now been several months since I finished this project and the inverter is still working great.

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