Hacked Gadgets Forum

January 31, 2010

LEGO Diffraction Grating Projector

at 12:24 pm. Filed under Cool Gadgets, DIY Hacks


I have never seen a project made with a Diffraction Grating before, but this LEGO Diffraction Grating Projector project has a great looking effect. It’s designed by Carl who was featured here before for his RGV Laser System. Those LEGO universal joints have a very wide working angle (watch the video to see what I am talking about).

Thanks for sending it in Carl.



January 30, 2010

DTMF Decoder Board Project using the MT8870

at 11:28 am. Filed under DIY Hacks, Electronic Hacks


Victor Youk from Razor Concepts has designed a nice DTMF Decoder Board Project. The project is based around the MT8870 DTMF Decoder chip. With this project you will be able to control something from around the block or around the world using a simple telephone. Nice feature of using the MT8870 is you don’t need to program anything, just purchase all the components, stuff them onto a breadboard and have a working circuit in a few hours. Victor has provided a full schematic so you can build your own.

MT8870_DTMF_Decoder_Datasheet (PDF)

“The heart of this device is the MT8870, which is a DTMF to BCD decoder chip. It takes an analog audio input, and converts that to a 4-bit binary output. Those 4 bits are put into a BCD decoder, and that converts that into the corresponding 0-9 output. Various other devices were needed to complete the board, and can be seen in the board layout below.”


Name the Thing Contest – 117

at 2:31 am. Filed under Contests


Thanks to Rocky Mountain Tracking for sponsoring the contest this week. They will be providing a Smart Tracker to the winner. The Smart Tracker is a GPS device that is mounted in your vehicle and can be used to track your vehicle in real time. Great if your car gets stolen or you forget where you parked it. πŸ™‚ You can use the NavIQ mapping software to pull up where your vehicle is on an easy to use map. Best of all unlike most of these units, this one does not have a monthly fee, you only need to pay when you want to use it. I wouldn’t mind paying $4.95 to know exactly where my car was right after it was stolen. Please note that this device can only be won by someone with a North American address.

“With our Smart Tracker gps device, you may activate and/or locate the device as the need arises. After a test period the unit will remain inactive until you need to track your vehicle, activation and location can be obtained online, at any time, day or night.

  • No monthly fees. Simply activate when vehicle is stolen or as needed.
  • Full end-user accessibility to our tracking software 24/7.
  • Activation and tracking on-demand as needed.
  • Geofence (parameter) alerts by text or email.
  • Low cost hardware and locates.
  • Advanced technology enables quick recovery.
  • Superior coverage in the U.S. utilizing hundreds of networks.
  • Easy two-wire install.
  • Internal back-up battery (optional).
  • Ideal for BHPH auto dealers.”

This contest will run for one week (January 30, 2010 – February 5, 2010) . Ending time is based on central standard time. To enter, identify the item pictured above and give an example of what can be done with it. Winner must have a North American Address.

Please do not give the answer in the comments.


Send an email to contest @ hackedgadgets.com with “Name the Thing Contest” as the subject, and the message body consisting of:

  • The name of the item in the above picture
  • An example of what the item pictured above can be used for

The winner will be chosen at random from all of the correct entries.


Added Feb 6, 2009

The item to guess was a Darlington Transistor

The winner is Dane K.


Below is a picture of the prize.


January 29, 2010

DIY Digital Light Dimmer

at 12:25 pm. Filed under DIY Hacks, Electronic Hacks


Here is a DIY Digital Light Dimmer that uses 2 push buttons to adjust the brightness output. Full details can be found here.


“The light level can be adjusted with two push-buttons “Up” and “Down”. Controller in this application is PIC16F84 that drives BUZ11 mosfet. Dimmer is tested with a light bulb 12V/4W and mosftet didn’t get even warm (which was expected since the datasheet says: 50V/30A).”

January 28, 2010

Basement Design Revolution

at 2:10 pm. Filed under Educational

I have seen the writing on the wall for many years now. It is now possible for a single person or a small team to crank out physical items just like the big players with huge factories. In this new age where circuit designs can be cranked out on the coffee table and sent out to China for production the next day is fantastic! The internet has shortened the gap between design and manufacturing. With the advent of inexpensive machines like the Maker Bot you can wake up with a brilliant design idea, cad up a quick design and print your plastic idea before the sun it up. If the idea is a good one ship off the electronic file to a facility to crank them out and move onto your next big idea.

As an example the Button Code project was designed in my home office. Parts were sourced from a electronic wholesalerΒ  and the board manufacturing was outsourced. All orders are electronic and most are sent out in kit form.

Chris Anderson from Wired and DIY Drones has written a great article which describes this exciting time, you owe it to yourself to check it out and be inspired.

“We designed the boards the way all electronics tinkerers do, with parts bought from online shops, wired together on prototyping breadboards. Once it worked on the breadboard, we laid out the schematic diagrams with CadSoft Eagle and started designing it as a custom printed circuit board (PCB). Each time we had a design that looked good onscreen, we’d upload it to a commercial PCB fab, and a couple of weeks later, samples would arrive at our door. We’d solder on the components, try them out, and then fix our errors and otherwise make improvements for the next version.

Eventually, we had a design we were happy with. How to commercialize it? We could do it ourselves, getting our PCB fab house to solder on the components, too, but we thought it might be better to partner with a retailer. The one that seemed culturally matched was SparkFun, which designs, makes, and sells electronics for the growing open source hardware community.”

Arduino Hard Drive Clock by NatureTM

at 11:09 am. Filed under DIY Hacks, Electronic Hacks

Long time Hacked Gadgets reader NatureTM has just completed phase 1 of his Hard Drive Clock. It’s using an Arduino to keep track of time and control the clock display LEDs. After accidentally letting out the magic smoke from the hard drive controller he decided to improvise and use a hobby RC motor speed controller. This clock will be super accurate when it is complete since it will eventually be using a Chronodot from Macetech.

Via: Hacked Gadgets Forum

“The first interrupt just records the time that the slot reaches the sensor and sets the position to zero. [It actually sets the position to the offset value since the sensor isn’t at 12 o’clock and I like to think of 12 as pos 0.] Now I can tell how long a rotation takes and how long it has been since the last completed rotation.

I have the rotation split into 180 divisions. I guess I’ll call them roxels (rotational pixels) since making up jargon is fun. I’ll call one full rotation of the platter a cycle. Then we know to draw the next roxel every cycle length/180. I then set arduino’s timer2 interrupt to overflow every new roxel and advance the roxel counter. I found this to be very efficient compared to other methods I tried. Actually, I was really proud when I figured this out, but I’ve been dying to know if everyone else is using this method as well. “

January 27, 2010

Dune Bug E – Dune Buggy Electric Conversion Part 2

at 8:00 am. Filed under Complex Hacks, DIY Hacks, Electronic Hacks


The next installment of the Dune Buggy Electric Conversion project is in. Since we brought you the 1st installment about a month ago there has been lots of work put into it. There are lots of interesting techniques that can be used next time you are working with some high current applications. I like the way the wire lug ends were made rather than bought. The frame is sure to be nice and level since it was laser aligned.

“The tube locations were determined with a laser-level and transcribed to a sheet of plywood. Two more pieces of wood (of the same size) were clamped to the template board, and drilled together to accurately place the holes for the tubing. The plywood sheets were squared and held together with lengths of scrap trim secured diagonally.”


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