Ancient laptop given new life as mobile prototyping platform

March 22, 2012 By Leave a Comment

What can you do with a broken Compaq SLT 286? Its briefcase-like size and shape actually make for a pretty interesting portable electronic prototyping station. [Philip] gutted the components and started adding back the items he most commonly uses when developing a project.

He shares all of the details in the video after the break. At center stage is a double breadboard where the keyboard would normally be found. It’s hard to make out in the image above, but there is a set of terminal strips running vertically to either side of these breadboards. Each terminal is connected to a peripheral or power/ground bus. The black knob to the left lets him adjust the output of a variable voltage regulator. To the lower right there’s a rotary encoder, push button, toggle switch, and a couple of potentiometers. These, along with the keypad and character display (mounted where the screen used to be) and DB connectors (on the back of the case) have their pins mapped to the terminal block to the right. [Philip] has mounted an Arduino Uno over the area to the bottom left, but we’re sure that it’s pretty easy to swap out for just about any breakout board he needs.

To answer [Philip’s] running dialog from the video: no, it is not the worst demo ever. We think you did a great job demonstrating all the features. Loose connections are par for the course when it comes to prototypes.

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Filed Under: arduino hacks Tagged With: , , ,

BB313 breadboard platform makes ATtiny prototyping painless

March 1, 2012 By Leave a Comment

Johngineer's BB313

[John De Cristofaro aka Johngineer] uses various ATmega microcontrollers in his electronics projects, but he finds himself reaching for an ATtiny2313 or ATtiny4313 more often than not. He got tired of having to wire up pin headers, capacitors, and the like each time he started a project, so he spent some time designing an easy to use breadboard platform around the chips.

Inspired by LadyAda’s Boarduino, his BB313 board features FTDI pin headers, an ISP programming header, a reset button, along with breakout pins that plug directly into any breadboard. Aside from sharing a similar layout, [John] says that the similarities end there. His board is designed for designers who program in C or C++, so Arduino code won’t run without some substantial modification.

The board looks like a pretty handy benchtop tool, and we’re pretty sure it would be a big time saver for anyone who uses these chips with any frequency. [John] says that the board cost about $6.50 to make when he put it together, but that prices might vary slightly depending on where you have your PCBs made.

Be sure to swing by his site if the design looks like it might be helpful. He has made the schematics, a bill of materials, and all the rest available for the taking.

[via Adafruit blog]

Filed Under: ATtiny hacks, hardware, Microcontrollers Tagged With: , , ,

Another take on using 'dead' batteries

February 29, 2012 By Leave a Comment

Here’s another circuit that can be used to squeeze the remaining potential from supposedly dead batteries. Just like the AASaver, we see this as a useful prototyping tool, providing juice for a breadboard even though it’s not reliable enough for long-term use (the batteries are just about through after all).

First off, the image above shows rechargeables instead of alkalines. We don’t recommend this as the circuit has no cutoff feature and the 0.7V input for the boost converter surely is below the recommended low-voltage limit for those cells. But that aside, we like the diminutive board which solders onto the end of a battery pack. It uses an SC120SKTRT which is a variable boost regulator capable of outputting 1.8-5V depending on resistor choices. You can leave the resistors off and it will default to 3.3V, set the output explicitly, or roll in some potentiometers and use your multimeter to tune the output.

This regulator costs more than the MCP1640 used in the AASaver, but it appears to use less passive components making for a smaller footprint. At a total of $3.50 plus the PCB (which will be a snap to etch at home) this is another great option to top off your next parts order.

[Thanks Uwe]

Filed Under: tool hacks Tagged With: , , , ,

Squeezing the juice out of some AA batteries

February 27, 2012 By Leave a Comment

[Ray’s] breadboard power supply lets you drain the last traces of power from ‘dead’ AA batteries. Electronics that are powered off of disposable alkaline batteries have a cutoff voltage that usually leaves a fair amount of potential within. Since many municipal recycling programs don’t take the disposables (you’re just supposed to throw them in the trash!) we love the idea of squeezing them for prototyping use.

His design uses just one IC, the MCP1640, along with a handful of passive components. The chip is a boost converter with a startup voltage of just 0.65V, which means the batteries themselves – normally starting life above 1.5V – can be used until they drop to about 0.3V each.

Above you can see the kit he is selling. But it’s an open source project and the circuit is so simple we’re sure you can build your own. Add that boost converter chip to your next parts order for around $0.40.

[Ray] made a nice demo video for the device which you can see embedded after the break.

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Filed Under: tool hacks Tagged With: , , , , ,