When working on battery-dependent projects you want accurate performance information where a datasheet may not be available. [E. Lelic] set out to build a device that would meter internal battery resistance but ended up with a bench tool that can do much more than that.
A PIC 16F88 microcontroller takes center stage on the meter, taking voltage level readings, monitoring a DS1820 temperature sensor, and controlling an LM2575 step-down regulator. The components provide functionality for measuring Lithium Ion, Lithium Polymer, Nickel Cadmium, Nickel Metal Hydride, and Alkaline batteries. It is capable of fully discharging and fully charging the batteries, measuring time and power consumption during this cycle, and monitoring temperature changes for the NiMH and NiCad versions.
Look for the little red ‘Download’ icon at the bottom of the post linked above. That archive includes a schematic (which we’ve also embedded after the break), board layout in .LAY format, and a HEX firmware file.
If you enjoyed this build you might want to look at this other battery capacity tester.
Continue reading “Full-featured battery tester puts them through their paces”
Hackaday forum member [Dan Fruzzetti] wrote in to share a simple, yet useful hack he built just the other day. He and his wife both have Evo 4G smartphones and they were pretty disappointed in the lack of portable charging solutions available.
Instead of buying something and modifying it to his needs, [Dan] decided to build a quick and dirty charger instead. His ghetto-mintyboost was built into a cheap project box he found at Radio Shack, which is stocked with a set of four D-cell batteries. The batteries were wired in series and connected to a pair of salvaged USB ports mounted on a small piece of protoboard.
Knowing that most portable devices get 5.7v from their chargers already, he was not worried about hooking his phones straight into the 6v battery pack he built. He says that the phones actually charge pretty quickly, and that he estimates he should be able to get about 50 charges out of the box before he needs to swap the batteries.
This is not a complex hack by any means. It is quick & dirty, solves an annoying problem, and it’s dead simple to build. That’s exactly why we like it.
[Nothinglabs] built this motor controller as an alternative to using an H-bridge. They call it the RAT controller which stands for “Relay and Transistors”. You can see above that two Darlington transistors along with their base transistors allow logic signals to switch the relay on and off, driving the motor in one direction or the other based on the open or closed state of the relay. See it working in the video after the break.
It’s a nice little workaround with few parts, but because the relay is mechanical there will be a short lifespan when compared to solid-state motor controllers. That’s okay, because the motivation here was lack of parts on hand, rather than an increase in performance. It’s also worth mentioning that all of these parts can be purchased at your local Radio Shack when you don’t want to wait for component orders by mail. We certainly appreciate that it takes far few components than [David Cook’s] H-bridges. His designs are our favorite – we’ve used them in our own projects – but for quick and dirty you can’t beat five components and the short assembly time needed when using this type of dead-bug style soldering.
Continue reading “Reversible relay-based motor controller”
Have a bunch of time on your hands, and about $2,500 sitting around? Why not settle in and build yourself a laser cutter?
That’s exactly what Buildlog forum member [r691175002] did, and he told us about it in our comments just a few moments ago. Laser cutters can be pretty cost prohibitive depending on what you are thinking of picking up. The cheapest Epilog laser we could find costs $8,000, and you know what can happen when you try buying a cheap laser online.
Instead of going for a ready-made cutter, he purchased an open-source kit from Buildlog, documenting the highlights of the build process online. The build log walks through a good portion of the construction starting with the frame and motor mounts, continuing through wiring up the electronics as well as some of the finishing touches. If you happen to head over to take a look around, you will find that there are plenty of pictures from various stages of the construction process to keep you busy for awhile.
With everything said and done, [Ryan] is quite happy with his laser. After going through the build process, he offers up some useful construction advice, as well as tips on sourcing cheaper hardware. He estimates that if he built the laser today, he could probably cut the costs nearly in half.
There’s no doubt about it – a $1300 laser cutter sounds pretty darn good to us.
The results are in and the new Open Hardware logo has been selected! After tallying nearly 9,000 votes it has been decided that “Golden Orb” by Macklin Chaffe will now represent the OSHW definition v1.0.
Rest assured that despite earlier controversy regarding a few users that had submitted a very large number of duplicate votes (over 3,100 in all), the results have been cleaned up and validated prior to announcing the winner.
If you agree with the definition you can now go ahead and use the logo on your creations! Some creative individuals at this Open Hardware Summit forum have made it easy for you with logos of varying sizes, colors, and fill – perfect for application on any background. Here you will also find vector-based versions and even an Eagle parts library for inclusion on your next board’s silkscreen!
[Jason] at MrDecals.com has also generously offered 3 free decals of the new logo to anyone who asks – just pay for shipping. Please note that this is not a paid advertisement, [Jason] received permission from opensourcehardware.org to run the promotion and $1 for US shipping seems very reasonable. We are guessing from the responses to previous giveaways that many HackaDay readers might be interested!
We personally love the way that the new logo keeps with the feel of the Open Source Intiative logo and can’t wait to see what hardware it starts showing up on!
[Gregory] wrote in to share his most recent project, an FPGA clone of the PC Engine/Turbografx 16 console. You may remember him from last year, when we talked about his SEGA Genesis FPGA clone. He just couldn’t leave well enough alone, and decided to resurrect yet another 16-bit machine in FPGA form.
He has been working on the project for about three months now, but he has been making very quick work of getting everything up and running. As of a few weeks ago, the project was in a pretty unstable alpha stage, but after pounding away at some bugs, he is now able to render any game he pleases.
The clone uses an Altera DE1 board just like his previous builds, and he has been able to emulate all three if the main chips that make up the Turbografx logic board. He has yet to work on the Programmable Sound Generator, but that is slated for the near future. While the FPGA currently stores ROMS in its flash memory, he has plans to add the ability to load games from an SD card.
Keep reading to see a pair of videos showing his console clone in action, it’s impressive.
Continue reading “FPGA-based Turbografx 16 clone”
We here at Hackaday have been pining over these cheap laser cutters on the e-bay. They are, however, just outside of the price range to make them worth ponying up for. [Stephen Hobley] however seems to have taken one for the team in his three part series, and is allowing us to live vicariously through is experiences.
Not surprisingly the price point leads to the potential for headaches. The units ship directly from China, and see their fair share of rough handling from package carriers. Broken/misaligned laser tubes are not uncommon (replacement tubes are prevalent). Shockingly the laser tube managed to survive the seven thousand mile journey! That only leaves a couple crucial modifications and careful cleaning and aligning to get the unit up and running. You didn’t think it would be that easy, did you?
To top off all the modifications adjustments and cleaning steps [Stephen] found (in part three) that his controller board was on the fritz. With a new one on the way from China, [Stephen] is debating either reverse engineering the included controller board or coming up with his own CNC solution. We could suggest quite a few alternate solutions ourselves.
We will be glued to [Stephen]’s blog for updates.
Stick around for a video of what we all really want to see, a laser burning stuff.
Continue reading “Buying a Laser Cutter From China”