Free Commodore ezine for retro enthusiasts

freeC64
For all you Commodore retro enthusiasts, there’s an online mag for you. Known as CommodoreFree, its a free to download magazine dedicated to Commodore Computers and is available in text, HTML and PDF formats, as well as including Commodore 64 D64 disk images. This ezine covers covering programming, gaming, hardware and Commodore related meetings. Its been in production since 2007. Past issues are available in their online archive, including article related software. The publisher’s website even has a downloads section with links to software and documentation.

App note: Current limit circuit for buck topology switching regulators

DI32Fig01

Here’s a current limiting circuit for buck topology switching regulators. This design monitors a shunt resistor and overrides the feedback pin of the switching regulator when the current limit is reached.

A current limit can be added to a step-down converter by using a MAX4173H current-sense amplifier to inject current into the feedback network. D1 sharpens the threshold of current limit by converting the current sense feedback signal from linear to exponential. This current-limit circuit can be scaled for any output current by adjusting R3. In this case, the MAX1692 provides up to 600mA output and the MAX4173H limits the output current by decreasing the output voltage for output current above 300mA.

Nintendo 64 handheld console

Want to play your Nintendo 64 games on the go? Travis took a N64 board, relocated the cartridge slot, and slapped on a 7” TFT & a battery. All of this is enclosed in a ABS plastic case with the original joypad buttons added for the interface.  The build photos are  3 minutes into the video.

Uses a full size N64 board with the cartridge slot relocated. 2 lithium ion batteries give you about 2-3 hours of play time, depending on the game played/brightness level. 7 inch widescreen, stereo speakers, original N64 controller buttons, and expansion pack. The case was made from a sheet of ABS plastic. Used bondo to get the smooth shape; the white paint is an automotive paint from Toyota(super white 040). Can be played from the internal batteries, or from wall power.

Via Hacked Gadgets.

Free PCB coupon via Facebook to 2 random commenters

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday.

Don’t forget there’s free PCBs three times every week:

Continue reading “Free PCB coupon via Facebook to 2 random commenters”

OWASP AppSecUSA 2012: reverse engineering .NET applications

Last October the Open Web Application Security Project (OWASP) AppSecUSA 2012 conference was held in Austin, Texas. In this conference video Jon McCoy presents the practical information on reverse engineering .NET Framework Desktop Software. The presentation goes beyond basics to illustrate modification of security areas of apps. The speech is intended to give a security professional the basic understanding of how to do a light Black-Box code analysis, as well as provide programmers with the basics of finding, fighting or producing malware.

Week in (p)review December 14, 2012

protoboard_demo.v1.11

Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.

Coming up:

  • Free PCBs via Facebook on Friday
  • App notes on the weekend
  • Free PCB Sunday
  • 3D model on Monday
  • Eagle parts and tips on Tuesday
  • Free PCBs via Twitter on Tuesday
  • A new tutorial on Wednesday
  • Workshop video on Thursday
  • Weekly roundup and preview every Friday

Bitbang USB v1.1 on a MSP430

MSP-EXP30G2

M-atthias was successful in running bitbang USB v1.1 on a MSP430G2452. It’s similar to the V-USB project that’s used on AVRs. It takes ~2kb of room on the microcontroller.

Yes, this is similar to the efforts of V-USB for AVR, but in a very early stage. I am in contact with Christian Starkjohann who wrote V-USB, and he helped me with valuable comments. Thank you !

Via 43oh.

Workshop Update for December 13th, 2012

protoboard_demo.v1.1

Today we edited the Tokyo Hackerspace video. Scanned receipts for China and Japan trips. Erected LED-adorned holiday post.

We decided to add an update to our protoboards inspired by Adrian’s comment. The QFP breakouts now support two pitches. Three combos will be available covering the most common pitches (0.8mm+0.65, 0.8mm+0.5mm, and 0.65+0.5mm)

Programmable timer switch

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Need a switch that turns on and off at set times? Here is a project by Victor that does exactly that. It’s PIC18F4550 based and uses a DS1307 real time clock chip to keep time. A small 12 volt relay acts as the switch.

This project, like others before, has started out of need: our 30+ year old mechanical timer for the central heater of the house has finally given it up. It would have been faster and cheaper to get a replacement from the local hardware store, but I decided to learn something new and I set out to create a digital version of it.

How to Add Custom Ringtones to a Wireless Doorbell

Want your doorbell to play prerecorded messages or tunes? This hack at instructables replaces the original speaker in a wireless doorbell with a 9 volt recording module.

Most doorbells just make a simple generic tone. But I thought that it would be fun to modify a door bell so that it has a customizable ringtone. That way you can set it to play music or custom greetings. You could make it to scream on Halloween and play carols at Christmas.

Via Hacked Gadgets.

TP-Link WR703n as telemetry link and camera broadcasting tutorial

wr703n

Here is a guide on how to setup the cheap TP-Link WR703n router to act as a telemetry link and an USB camera broadcasting server. The guide is in three parts, starting from flashing the OpenWrt firmware, adding a USB hub and extending the memory with a USB flash drive, and finishes with explaining how to attach a camera.

 

Digital IR theremin


Chris from Pyroelectro developed this all-digital-hardware Theremin. He descibes, “The Digital IR Theremin uses comparators, digital logic, and a single 555 timer for tone generation. When you wave your hand in front of the infrared proximity sensor, it outputs a tone with varying pitch depending on how far away your hand is from the sensor!”

The BOM includes a 7805 +5v regulator, four LM339 Quad Comparators, two 7408 Dual And Gates, a 555 Timer, IR proximity sensor, eight 2N2222 Transistors and a handful of resistors, capacitors and miscellaneous supporting components. For more details and photos visit Pyroelectro.

Via the contact form.

Prototyping your PCBs in Europe or in China?

To use European or Chinese based PCB prototyping services is the question Electronics Lab tries to answer. They order the same PCBs from an European and a Chinese PCB manufacturer, and compare the quality and price differences. Based on their review the quality is the same, while the Chinese board is more than 5 times cheaper.

AVR programmer from an old USB keyboard

Steve takes apart an USB keyboard and mods it into an AVR programmer. All it takes is the controller board from a keyboard and an opto-coupler IC.

Most keyboards have at least three indicator LEDs (Num-,  Caps- and Scroll-Lock), which can be controlled from the host using a HID Set_Report request, and thus can be used as general purpose outputs. The inputs are a bit more tricky, since the keyboard uses a scan matrix divided in rows and columns. Most keyboards also do some debouncing and detect rows that are ‘stuck’, which means that we need to simulate the keypress of a single key. If a key has been pressed, the keyboard triggers an interrupt transfer with 8 bytes of data, containing the current state of all keys. The first byte reflects the state of the modifier keys (shift, ctrl, alt, etc.) which I’ll be using as inputs. Additionally, the keys can be polled using a Get_Report request to the control endpoint, but the interrupt transfers need to be handled either way, since my keyboard just locked up after the first keypress when I didn’t handle them first.

Via Embedded Lab.

TXB0108 level converter breakout board

Have loads of 5 volt hardware you can’t use with your new 3.3 volt Stellaris Launchpad (or other hardware)? Mike solved this problem by building a level converter using two TXB0108 ICs

And here is the proof that it works. I’m driving a 5V graphic LCD using the 3.3v Stellaris Launchpad. The TXB0108 level converters have two voltage inputs. The lower voltage goes to VCCA and the higher voltage goes to VCCB. Each chip provides eight pins on either side for easy connections.

Via the contact form.

How to give your Arduino wireless capability

It seems the Ethernet Shield is unnecessary if you want to connect your Arduino to WiFi via the cheap TP-Link WR703N router. This is due to the fact that the router can be hacked with OpenWrt making it a Linux box with a fully functional USB. For those of us who are not afraid of solder fumes, there is also the possibility to connect a microcontroller directly to the serial lines of the router.

Via the comments.

Bus Pirate v3.6 Sick of Beige v1 acrylic case v1 back in stock

Bus Pirate v3.6 Sick of Beige acrylic case v1 is back in stock at Seeed Studio. Version 1 of the basic case is simple, cheap, easy to assemble, and fits our Sick of Beige standard PCB sizes.

Check out our tutorial on how to customize Sick of Beige cases.

Get Bus Pirate v3.6 acrylic case v1 for $3.

EHSM open source meeting in Berlin December 28-30


Kaspar writes informing us of the premiere of the uniquely named Exceptionally Hard and Soft Meeting (EHSM) which will be held in Berlin, Germany on December 28-30, 2012. “EHSM is turning out to be something like the OSH Summit this side of the pond. Online sales are closing on the 16th so I am just helping in a bit of a publicity push.”

Visit the EHSM website for a full list of speakers and more details.

Via the contact form.