Author: Zoe Skyforest

3718 Articles

Upgrading The Batteries In A BMW I3

February 1, 2021 by 42 Comments

The BMW i3 debuted on the market in late 2013, one of the brand’s first electric cars. Also available with an optional range-extending engine, early models featured a 60 Ah battery providing up to 130km range on a full charge. However, times have changed, and over the years, BMW have updated the model with larger capacity batteries over the years. So what does it take to retrofit an older model with the newer, fatter, juicer 120 Ah pack?

It’s all helpfully laid out in a video by [Daniel], who notes that it’s not a job for the faint of heart or poorly equipped. The good news is that, mechanically, the newer batteries have the same external dimensions as the older packs, meaning they can be bolted in without requiring any cutting, welding or, adapters. But that’s about it for the good news. The batteries are cooled by the air conditioning system, meaning that removal and replacement means draining the system of refrigerant using highly expensive specialised hardware. Additionally, many batteries in crashed cars are disabled when the airbags are triggered for safety reasons, requiring unlocking through BMW’s proprietary software or replacement of the internal battery controller. Then there’s the usual laundry list of gradual changes that happen across any automotive line, meaning that certain model years and trim packages can have incompatible plugs and connectors or other features.

Overall, it can be quite a bit of work to do, and with the tools required, something that needs the services of a dedicated mechanic’s workshop. However, find an experienced shop that regularly works with EVs, and you might find they can facilitate the upgrade for you without too much fuss. We’ve seen [Daniel] tackle upgrades before, such as a much easier swap on the Nissan Leaf. Video after the break.

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Adding Remote Control To An Old Stereo

January 29, 2021 by 17 Comments

Sometimes, the best hifi gear is the gear you’ve already got. This is particularly the case in the cassette world, as high quality decks are long out of production. [Nick] liked his current rig, but wanted to be able to use it with a remote from across the room. Naturally, he set to hacking the feature in.

The cassette deck in question, a Yamaha K-220, was old enough to lack a remote, but thankfully new enough to use a computer-controlled tape transport. This meant that the basic features of play, stop, rewind and fast forward can all be controlled with simple digital buttons rather than mechanical ones. This made it easy to interface an ATmega328P to the stereo’s original circuitry. Digital IO pins are hooked up to the buttons, held as high-impedance inputs most of the time, only toggling to ground when necessary to trigger a button press. It was then a simple job to hook up an IR receiver to the chip and program it with some Arduino libraries to work with a typical stereo remote control [Nick] had laying around.

It’s a tidy build, and with more cool cassette releases coming out every year, we’re sure [Nick]’s going to put some miles on the setup. If you find IR too cumbersome though, you can go a step further and replace it with a web app instead. If you’ve been tinkering with similar things in your own workshop, be sure to drop us a line!

Randonaut Device Tells You Where To Be And When

January 28, 2021 by 5 Comments

Randonauting is the pastime of using random numbers to generate a destination to visit, in the pursuit of adventure. Of course, anything that can be done on a website with a script is even cooler with custom hardware, so [Decker] built a rig for the job. 

The device uses a USB hardware random number generator to produce truly random numbers through quantum effects; at least, according to our best theories of the universe. These numbers are then used to pick a random set of GPS coordinates and a time in which to be there, a fun twist on traditional Randonauting of [Decker]’s own creation.

At its heart, it’s a random number generator pumped through some Python scripts. Where this build elevates itself is not in the mechanics, but the presentation. The rig runs on a Raspberry Pi, inside a bell jar, with a vacuum fluorsecent display, fairy lights and plumbing components. It plays on the cyberpunk aesthetic, and it’s so much harder to ignore one’s mission when the time and place are given in glowing numerals by an enigmatic, mysterious machine.

It looks like great fun, though beware the dangers of randonauting – some participants have found more then they bargained for. It’s not dissimilar to the old geohashing craze. Video after the break.

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Apple Watch Gets Custom Transparent Case

January 27, 2021 by No comments

The Apple Watch was the tech company’s attempt to bring wrist computers into the mainstream. It’s naturally available in a variety of fits and finishes, but if you want something properly original, you’ve got to go custom. [Useless Mod] does just that with a clear case for the popular smartwatch.

The mod starts with a patient, careful disassembly of the watch – necessary given the delicate components inside. It’s achieved in the end with only having to drill out 1 screw and an unfortunately snapping of the crown wheel axle. However, [Useless Mod] presses on, and silicone casts the original Apple enclosure. The video goes over all the finer points, from degassing to using strips of acrylic plastic to act as runners. Once done, the silicone mold is used to produce a replica case in transparent epoxy, and the watch is reassembled.

The final result is impressive, with the case optically clear and showing off the watch’s internals. The look is improved by removing some of the original insulation tape to better reveal the PCBs inside. Unfortunately, the design of the watch, which is largely covered by a screen and heartbeat sensor, means it’s not the greatest choice for a clear case mod, but it works nonetheless. We’ve seen similar work before from [Useless Mod] too – like this transparent drone case for the Mavic Mini. Video after the break.

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Sony’s Electric Car Now Road Testing In Austria

January 27, 2021 by 73 Comments

The Consumer Electronics Show was not typically a place for concept cars, and Sony aren’t known as a major automaker. However, times change, and the electric transport revolution has changed much. At the famous trade show, Sony shocked many by revealing its Vision-S concept — a running, driving, prototype electric car.

Far from a simple mockup to show off in-car entertainment or new fancy cameras, Sony’s entry into the automotive world is surprisingly complete. Recently, the Japanese tech giant has been spotted testing the vehicle on the road in Austria, raising questions about the future of the project. Let’s dive in to what Sony has shown off, and what it means for the potential of the Vision-S.

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Custom Bite Sensor Replaces Keyboard Expression Pedal

January 26, 2021 by 2 Comments

Sometimes, standard hardware won’t do when it comes to the differently abled. [Ben Krasnow] found himself recently working on a project for a musician who doesn’t have the use of his legs, and thus needed to create a new interface to replace a standard expression pedal.

[Ben] is a big fan of the build first method of working, and demonstrates why it works well. In this case, the first attempt involved a pneumatic design, where the user would bite down on an air bladder that actuated a remotely-located potentiometer via a tube and bellows. However, while this design worked, the tactile feedback was poor. This led to experimentation with mechanical designs, with an initial attempt involving a 3D printed mechanism and a rotary pot. This was better, but still had problems with damage from teeth and poor feel .The final design is essentially an analog button, built with fabric-impregnated silicone for wear resistance and using a linear pot for smooth feedback.

The final design is impressively tidy, and [Ben] notes that while it looks simple, it was only arrived at by trying plenty of worse solutions first. We’ve seen other work done in the gaming world too; recently, modular controllers have come into vogue to serve a wide variety of needs. Video after the break.

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How To Run Alternative Batteries On The DJI Mavic Mini

January 25, 2021 by 40 Comments

Rechargeable batteries are ubiquitous these days, freeing us from the expense and hassle of using disposable cells. However, this has come with the caveat that many manufacturers demand their equipment only be used with their own official batteries. [aeropic] wasn’t a fan of this, so built a circuit to allow his DJI Mavic Mini to fly with any batteries he pleased.

The Mavic Mini uses I2C to communicate with official packs, making the hack relatively straightforward. [aeropic] built a board nicknamed B0B, which tells the drone what it wants to hear and lets it boot up with unofficial batteries installed. The circuit uses a PIC12F1840 to speak to the drone, including reporting voltage on the cells installed. Notably, it only monitors the whole pack, before dividing the voltage to represent the value of individual cells, but it shouldn’t be a major problem in typical use. Combined with a few 3D printed components to hold everything together, it allows you to build your own cheap pack for the Mavic Mini with little more than a PCB and a few 18650 cells.

It’s always good to see hackers getting out and doing the bread and butter work to get around restrictive factory DRM measures, whether its on music, printer cartridges, or drone batteries. We’ve even seen the scourge appear on litter boxes, too. Video after the break.

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