[shakirfm] sent us this LED persistence of vision (POV) laser projector that can display dot matrix style text. The laser projector contains a rotating mirror assembly and 5 lasers. We’ve covered other POV projectors,but this one is a bit different. The mirror assembly rotates using two cooling fans. Controlling on/off times of the lasers along with the mirror speed, it is able to project 8×5 dot matrix ASCII text onto a surface.
Continue reading “Laser POV Projector”
Every project needs a power supply. As 3.3volt logic replaces 5volt systems, we’re reaching for the LM317 adjustable voltage regulator, rather than the classic 7805. We’ve found four different hobbyist-friendly packages for different situations.
A simple voltage divider (R1,R2) sets the LM317 output between 1.25volts and 37volts; use this handy LM317 calculator to find resistor values. The regulator does its best to maintain 1.25volts on the adjust pin (ADJ), and converts any excess voltage to heat. Not all packages are the same. Choose a part that can supply enough current for your project, but make sure the package has sufficient heat dissipation properties to burn off the difference between the input and output voltages.
Continue reading “Parts: LM317 Adjustable Voltage Regulator”
[Steve DiRaddo] sent us this sweet little mod. After obtaining a free LCD TV that had a cracked screen, [steve] immediately tore it open to re purpose it. The end result was a computer controlled light table with audio. From what he says, it is very very bright due to the fact that it has 16 CFL tubes behind it as opposed to the usual 2 inside a PC monitor. The TV had a bult in RS232 command port. Whith some quick hacking, he was able to control power, channel, input, and volume via his laptop.
With the weather getting colder, [Daniel] decided it would be a good idea to monitor how much energy his gas heating was using in real time. He used a Nokia 6680 cameraphone to monitor the heater’s flame through the sight glass. PyS60, a Symbian implementation of Python, checks the image sent by the camera and measures how much blue flame is visible. These values are stored in a SQL DB on the phone that can be polled over Bluetooth. At the end of the billing cycle, he’ll be able to correlate the amount of gas used with what the phone reported.
[Thanks, florent bayle]
[youtube=http://www.youtube.com/watch?v=f3iOuKzhUlQ]
Reader [deren lik] pointed out the world of direct to garment printing to us. You can purchase commercial machines that will print directly onto a t-shirt using inkjet technology. Unfortunately, these machines cost ~$10K, so hackers have decided to fill in the gaps. DIYDTG hosts plans for how to build your own DTG printer. Their standard instructions are based around the Epson C88 printer. A custom carrier is constructed and then the printer components are bolted on top. Commercial DTG printers are also based on Epson parts and you can easily purchase the garment inks even if you didn’t pay a premium for your printer.
We’ve seen those videos where people take a picture of themselves every day. [Dan Hanna] took it to a much further level. He built a camera rig and took pictures of himself for 17 years. That is not a typo, 17 years. The rig consists of a ring that holds two cameras opposing each other. He centers his head facing a target that he increments around the ring every day before taking a picture. The ring can be split into 4 sections for portability. Check out the low resolution video after the break.
For years, Microchip PIC microcontrollers dominated; PIC16F84 hacks and projects are everywhere. The 8-bit 16F and 18F lines are supported by several coding environments and easy-to-build serial port programmers. Microchip’s 16-bit PIC24F is cheaper, faster, and easier to work with, but largely absent from hacks and projects.
We recently used a Microchip PIC24F microcontroller in a mini web server project, but didn’t find many introductory references to link to. In this article we’ll cover some PIC 24F basics: support circuitry and programming options. We’ll also talk about our favorite features, and how we figured them out. Our next article will outline a web server on a business card based on the PIC 24F.
Continue reading “How-To: Web Server On A Business Card (Part 1)”
