Simple RFID Access System Clone

February 7, 2011 by 7 Comments

rfidbboards

A few months back, [John] was reading an article about a simple RFID security system kit, and decided he would like to build one himself.  While many of the system’s details, including full schematics were provided, he was dismayed to find that the source code for the project was not published as it was held under copyright by the manufacturer.  Believing that open source is better, he modified the original design, replacing their PIC controller with an ATmega328 armed with an Arduino bootloader.

His system replicates all of the original kit’s functionality, while offering plenty of opportunity for modification beyond the initial design.  The article contains a complete parts list, wiring schematic, and the Arduino code required to get things up and running.  He even has a video of his clone at work, demonstrating the acceptance and rejection of RFID tags as well as the system’s learning mode.

Paintball Chronograph

February 6, 2011 by 20 Comments

This slick little chronograph can tell you how fast your paintballs are going, as well as what your firing rate is. In this instructible by [Klash69], you can see how to build one for yourself for less than $40. Chronographs themselves aren’t usually too interesting, but we thing he has done a great job here. You have a nice compact package with a big bright display. All it really needs now is a smooth enclosure. As far as the tech details go, he’s using IR sensors spaced 4 inches apart for detection, at the barrel. We’re not experts, but we think this might not work as well on a gun due to muzzle flash, someone who actually knows should let us know in the comments. The brains are a PIC18F13k50 and you can download a full parts list and schematic on the instructible.

You can see a video of it in use after the break.

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Versaloon Ported To STM8 And STM32 Discovery Boards

February 6, 2011 by 11 Comments

[Bingo] did some work porting Versaloon for STM8 and STM32 discovery boards. Versaloon is a multiple-architecture programmer that we saw a few weeks back. At its center is an STM32 microprocessor, which greatly simplifies the work necessary to use the two discovery boards instead. Flashing the firmware to the boards will zap the ST-link firmware and [Bingo] doesn’t know of a way to restore that so be warned. This hack is still pretty fresh off the bench, but so far it looks like vsprog and OpenOCD both work just fine with the new hardware.

Switched Mode Power Supply Repair Guide

February 6, 2011 by 46 Comments

switched_mode_power_supply_repaiir

[Erich] spotted a broken DVD recorder at a local amateur radio meeting and decided to see if he could restore it to working order. While he was fortunate enough that someone labeled it as having a bad power supply, things aren’t always that easy. He gives a broad explanation as to how switched mode power supplies work as well as discusses some of the reasons these devices tend to fail. He identifies a few common components and areas that one should check while diagnosing a non-functioning power supply. While obvious bulging capacitors are easily identifiable, he discusses the need for an ESR meter and uses a kit-built model to test capacitors that do not have any visual signs of damage. While some of his walkthrough might be basic knowledge for readers who have experience in recapping circuit boards, it serves as a nice guide for those who are new to the world of electronics troubleshooting and repair.

Microsimon

February 6, 2011 by 7 Comments

[Simoninns] is hoping to compete in the Sparkfun Microcontroller Contest with this cool little Microsimon instructible. The parts list is pretty small, at around 20 components. At the heart is a PIC 12F683 microcontroller. The whole project is very well documented with schematics, PCB layouts, code, and great pictures. This is a great project that you could put together really quickly and is a perfect introduction to charlieplexing. We find that, especially when teaching a new person, games are often a good project to learn from. The interactive and competitive nature of the finished product usually keeps people interested a little longer. You can catch a video of it after the break.

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The Energy Detective TED 5000-G Teardown

February 6, 2011 by 18 Comments

Ted 5000-G Teardown

Before [Steve] realized that it didn’t play nice with his network, he dismantled his Energy Detective TED 5000-G to see what made the device tick. He put together a nice teardown with high-res pictures throughout.  Each component of the TED 5000-G is dissected, with the exception of the current transformers, which he claims are pretty boring anyhow.  The gateway module is particularly interesting as it contains both an Ethernet interface as well as a 802.15.4 radio for wireless communications.  While the device is still a bit expensive at the moment, the gateway module could be useful in projects requiring PLC or ZigBee communications some time down the road, once prices ease a little.

10 µm Scanning Electron Microscope From Vidicon Tube

February 6, 2011 by 13 Comments

[Segelfam] built his own scanning electron microscope. He based the machine around an old Vidicon tube, a video recording technology that was used in NASA’s unmanned space probes prior the Galileo probe in the late 1970’s. We struggle a bit with the machine translation of [Segelfam’s] original build log, but it seems that he filled the tube with helium in order to convert it for use as a microscope. But don’t worry, if you’re interested in this hack the information is all there – between the forum thread and build log – it’s just a matter of putting it all together to fill in the details.

In case you were wondering, the image to the upper right has been colored using Photoshop; the rest are straight from the SEM.

[Thanks Jerry]