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Published on: September 12, 2013 / Comments: None

TraID the automated transistor type and pinout identifier

Matseng put together a nifty tool that can quickly identify both the transistor type, and the correct pin out.  We posted a method earlier on how to determine these characteristics manually, but where’s the fun in that ?  Part of his self set goal of making a Project A Week, this is his 22nd week project.

His design uses a PIC16LF1503 microcontroller and is powered by a CR2032 coin cell battery.  It uses LEDs and silk-screen markings to show you the output.  On the PCB there are holes for common transistor configurations such as to-92, to-18 and to-220 that you can insert to be identified.  The part is given a voltage in different configurations and read back using the PIC’s ADC.

Source code and schematic are provided on his post to the Dangerous Prototype’s forums.

Published on: August 27, 2013 / Comments: None

Taking apart a bluetooth OBD-II interface

Isn’t it fun to take stuff apart and see how things are made ?  Well Michael over at EDN likes to as well!  He’s got one of those cheap-y eBay Bluetooth OBD-II adapters and while what’s inside isn’t much of a shocker, it’s still nice to look at how things are made.

Inside is a bunch of power regulation, a CAN bus transceiver, a Microchip PIC and a ready-made bluetooth module.  Usually when you crack these cheap clones apart the soldering looks pretty shoddy, but this one looks pretty clean except for the Bluetooth module for some reason.

Check out the full teardown.

Published on: August 26, 2013 / Comments: None

Data into smart phones and tablets via audio

You have probably seen those little dongles that let people swipe their credit card on their smart phone or tablet.  These little dongles transmit data to the device via the microphone jack.  The audio recorded is then examined and the data is either a one or a zero.

In the example described by the article, they are using a PIC and the data is encoded via manchester encoding.  A resistor and a pot are used to tweak the output level.  This is a great way to send data to a smart phone or tablet without making any crazy custom dongles but you are limited in capabilities.

Schematic and example source code is included in the post.

Published on: August 12, 2013 / Comments: None

Making use of those unused buttons on your remote

On the 20 some-odd remotes I have around the house, I know there are a bunch of buttons on some of them that don’t do anything for my model of whatever it controls.  Badr noticed the same thing on his satellite receiver.  So he decided to give those extra buttons something to control.

Armed with a little IR transmission know-how, a 16f84a, a transistor array and some relays he added support for controlling his some lights and a fan.

He’s got a schematic and source code up here.


Published on: August 2, 2013 / Comments: 1

Mini R2D2 just made my want list

Michiel has a build log of his mini R2D2 project over at letsmakerobots and its turning out really awesome.  I’ve seen the hard core guys who build full scale replicas but never really thought of building a miniature.  He’s broken the build out into sections like Dome, Body, Legs, etc.



He doesn’t have the electronics section up but he is using a Raspberry Pi and a Picaxe micro controller.  I would  guess the Pi handles the main control paths and the Picaxe doing most of the sensor feedback, servos and leds.

Published on: July 27, 2013 / Comments: None

Magnets (on stepper motors) How do they work ?

I’m always a big fan of learning more about  Why  vs  How .  Once you understand what’s really happening inside the black box, you can interface with it better after you really know its needs.  Siddharth  is here to school you and teach you more about stepper motors.  If you’re thinking about building things like robotic arms, or 3D printers you’ll most likely use a stepper motor.  DC motors are good for most things, but stepper motors allow you to get accurate with your precise location while giving you lots of power at the same time.

This is one of those articles you need to bookmark for later when you are actually working on something using steppers.  The diagrams showing the differences between 4/5/6 and 8 wire configurations, and Full step, half step and microstepping are going to be valuable to refer back to.  I sware every time I hook up a 6 wire stepper to a 4 wire controller I have to google it each time.

Siddharth also has a follow-up article where he interfaces the stepper to a PIC microcontroller.

Published on: July 24, 2013 / Comments: 1

Using the Peripheral Pin Select feature on a PIC24

pic24fjxxgb004Part 6 of Modtronics Australia’s PIC24 tutorial series,  Modtronics shows you how to use the Peripheral Pin Select feature on a PIC24 microcontroller.  This feature allows you to remap which pins are tied to which peripheral such as uart, I2c, SPI, etc.  Very useful feature when it comes to laying out a board, allowing you to lay things out because of convenience rather than necessity.  This could also lead to reusing of a certain pinout adapter across multiple configurations since it can be selected via software.




Other useful tutorials in this series: