Squeezing The Juice Out Of Some AA Batteries

[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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Hackaday Links: December 3, 2011

Honey, would you like some cheese? WHIRRRRRRRRR

[The Timmy] broke his manual cheese grater. It would be a waste to throw away a perfectly functional tool that’s only missing a handle, so he kicked it up a notch with a cordless drill. Now [Tim], “can grate with incredible speed and power for even the toughest of cheeses.” Anyone have a broken pepper mill?

The most adorable oscilloscope

We’re not much for plugging products, but this scope is really cool. It’s designed to fit on a breadboard and is smaller than some ICs we’ve seen (68000, so yes, it is). We’re wondering why there hasn’t been a homebrew version of this yet.

Now do an R/C castle

Here’s a minifig-sized R/C LEGO car made by [brickmodder]. It has a custom drive train and steering mechanism that uses the smallest servos [brickmodder] could find. How about an R/C pirate ship next?

It’s probably an ad for something

Here’s some sort of code thing that asks the question, “Can you crack it?” Apparently, it’s for UK cryptanalyst recruiting. You won’t get a 00-designation, but woo Bletchley Park.

Inverting an inverter

[Manfred] is putting an alternative energy setup on his land. Of course he needed an inverter to charge his batteries, so he went with a highly regarded (high price) box. What he got was anything but. You’re going to need at least ten minutes to go through this hilariously sad teardown of a high quality Taiwanese inverter. Oh, [Manfred] is awesome. Just look at his microhydro plant.

Bread Head Makes AVR Programming A Snap

bread_head_quick_avr_programming_header

[Quinn] over at Blondihacks has been working with AVR microcontrollers a lot recently, and wanted a quick way to program the ATtiny13a (her current AVR of choice) while the chip is still seated in a breadboard.

To speed up code revision and testing, she built a small programming header that she calls the Bread Head. The device is wonderfully simplistic, consisting of little more than snappable header pins and a bit of upside-down protoboard.

She soldered six headers to the top (formerly the bottom) side of the board, while a set of eight oversized headers were soldered to the opposite side of the programmer. Small bits of wire were soldered in to connect all of the appropriate pins together before [Quinn] slipped the header snugly over the top of the ATtiny and gave it a quick test. Everything worked perfectly, so she slathered in in epoxy for sturdiness and called it a day.

She says that the programmer works so well that she’s likely to make a similar header for other common AVRs too.

DIY Breadboard Modules For Easy Prototyping

[Rajendra] got tired of building the same basic circuits time and again on the breadboard. He decided to build some simple, modular circuits on protoboard and make them easy to interface with the breadboard. As you can see, he ended up with seven modules that make prototyping faster and easier.

At first glance some might not seem all that beneficial. For instance, making a board for an 18-pin PIC microcontroller into a single-in-line form factor would seem like you’re actually wasting breadboard space when compared to the DIL package of the chip. But consider that the oscillator and its capacitors, reset button, and programming header are also on the breakout board and will not have to be built in place. There are also several I/O boards, one with five buttons, another with an LED bar graph, and a set of LEDs with a SIL resistor package on-board. These modules can be plugged into a breadboard and wired up with jumper wires, or connected directly to the same rows as the microcontroller module.

A Light-Following Pong Game

Although not everyone has the ability to make a hacked Pong game Like [Marcelo], even fewer have the ability or the creativity to come up with the elaborate hack that he did. The basic premise of his game is a version of pong played on a breadboard with a 8×8 matrix of LEDs. The controls are really what sets this hack apart. Instead of using a paddle controller or normal switches, small flashlights are used to control the on-screen (on-LED matrix) paddle. This is accomplished using a series of photoresistors and a PIC processor.

Innovative as this would be by itself, [Marcelo] decided to make a program in Flash to display the action on a computer.  Communication is done serially, and C# is used to translate everything as Flash doesn’t natively work with a serial connection.

Another innovation is that there are two LEDs connected on either side powered via pulse width modulation. The lights get dimmer as one player is about to lose. Check out [Marcelo’s] pong game after the break!

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Juice Bridge Powers Your Breadboard In A Snap

juice_bridge_breadboard_power_bridge

[Quinn Dunki] got tired of messing around with wires when connecting things to her benchtop power supply, so she built herself useful little power bridge that plugs directly into any standard breadboard.

The board is small and simple, but quite useful all the same. It was built to power both sides of the breadboard, and it can be easily switched between an unregulated power supply and a regulated 5v supply. An ammeter can be attached to the board via a pair of pins she set aside, allowing her to easily measure the current draw of the entire circuit.

We think her “Juice Bridge” would be very useful to anyone who frequently prototypes on breadboards. In fact, it would be a fantastic beginner project since it involves etching and developing PCBs as well as some simple soldering, while resulting in a handy takeaway tool at the same time.

If you want to build one of your own, [Quinn] has the schematics and Eagle PCB files available for download on her site.

Dead-bug Arduino Is Still Breadboard Ready

Here’s a no-PCB Arduino that doesn’t obscure the DIP footprint of the AVR chip. It’s built on an ATmega88 chip, and includes a programming header, reset button, a couple of filtering caps, and an LED. This is modeled after the Lilypad hardware, and fits nicely on top of the plastic case of the microcontroller, allowing it to be used in a breadboard or DIP socket. You can see a walk through of the components in the clip after the break.

We don’t really need most of the components on top of the chip (especially the status LED on the SCK line), but there are several things that we like about this. First off, the programming header is extremely nice. We could see this coming in handy for prototyping where you don’t want to add a header to your final design. Just use a chip socket, and this chip while you’re developing firmware. Once everything is dialed in, program a naked chip and swap the two. The same goes for the reset button, which is nice when working on firmware but may not be necessary in your final design.

This is quite an old project, and we’ve actually seen a successor to it. This is Rev. 2 and we looked in on Rev. 7 back in March. That one is a full Arduino, but the circuit board has no substrate.

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