Charge All Your Batteries With USB PD

USB-C has been around for a while, and now that it can charge phones and Macbooks and Thinkpads, the hackers are starting to take note of power adapters that can supply lots of current. [Alex] was turned on to USB-C after he charged a laptop, Nintendo Switch, and phone with one power adapter. This led him to create a USB-C battery charger for all your LiPos.

The high-level design of this project is simply a board with a USB C port on one end, an XT60 plug on the other, and some support for balance leads. Plug this board into a USB C adapter, plug a battery in, and the battery will charge automagically. The only UI is an RGB LED. It’s difficult to imagine a battery charger that’s easier to use.

For the electronics, [Alex] is using an STM32G0 for the smarts of the device, which includes handling the USB PD spec. This gives the charger 20 Volts to play with, and this is then regulated and sent into the battery. Right now, this board will charge 2-4c batteries. That’s a good enough proof of concept to charge some quadcopter batteries, or just as a really simple way to charge some LiPo cells.

Simple Timer Evolves into Custom Kid’s Watch

Sporting a new wristwatch to school for the first time is a great moment in a kid’s life. When it’s a custom digital-analog watch made by your dad, it’s another thing altogether.

As [Chris O’Riley] relates, the watch he built for his son [Vlad] started out as a simple timer for daily toothbrushing, a chore to which any busy lad pays short shrift unless given the proper incentive. That morphed into an idea for a general purpose analog timepiece with LEDs taking the place of hands. [Chris] decided that five-minute resolution was enough for a nine-year-old, which greatly reduced the number of LEDs needed. An ATtiny841 tells a 28-channel I2C driver which LEDs to light up, and an RTC chip keeps [Vlad] on schedule. The beautiful PCB lives inside a CNC machined aluminum case; we actually commented to [Chris] that the acrylic prototype looked great by itself, but [Vlad] wanted metal. The watch has no external buttons; rather, the slightly flexible polycarbonate crystal bears against a PCB-mounted pushbutton to control functions.

With a snappy wristband, [Vlad] will be rolling fancy on the schoolyard. It’s a great looking piece that needed a wide range of skills to execute, as all watches do. Check out some other watch builds, like this lovely pure analog, another digital-analog hybrid, or this pocket watch that packs an Enigma machine inside.

Continue reading “Simple Timer Evolves into Custom Kid’s Watch”

Plug Your Ears And Hop On This Jet-Powered eBike

Ah, the simple pleasures of a bike ride. The rush of the wind past your ears, the gentle click of the derailleurs as you change gears, the malignant whine of the dual electric jet turbines pushing you along. Wait, what?

Yes, it’s a jet bike, and its construction was strictly a case of “Why not?” for [Tech Ingredients]. They recently finished up a jet engine build using a hybrid design with electric ducted fans as compressors and fueled with propane. It was quite a success, and pretty spectacular, but left an embarrassment of riches upon its passing in terms of spare parts. The ducted fans, monstrous 90-mm 12s beasts, along with dual 150A ESCs found their way onto a mountain bike by way of a rear luggage rack. Pannier bags on each side hold the batteries, and a quick control panel went on the handlebar. The video below shows the build details and a couple of test rides, which show just how fast you can go with this setup. It may not be very practical compared to a more traditional hub motor, but it’s nowhere near as cool. Just be sure to wear your hearing protection.

Is this the first jet engine on a bike we’ve featured? Of course not. But for an impromptu build, it’s pretty impressive. Continue reading “Plug Your Ears And Hop On This Jet-Powered eBike”

Tiny Solar Energy Module (TSEM) Brings Big Performance

The Tiny Solar Energy Module (TSEM) by [Jasper Sikken] is not only physically tiny at one-inch square, but it is all about gathering tiny amounts of solar energy — amounts too small to be useful in a conventional sense — and getting meaningful work done, like charging a battery for later use. Elements that make this board easy to integrate into other projects include castellated vias, 1.8 V and 3.3 V regulated outputs that are active when the connected battery has a useful charge, and a low battery warning that informs the user of impending shutdown when the battery runs low. The two surface-mount solar cells included on the tiny board are capable of harvesting even indoor light, but the board also has connection points for using larger external solar cells if needed.

The board shows excellent workmanship and thoughtful features; it was one of the twenty Power Harvesting Challenge finalists chosen to head to the final round of The Hackaday Prize. The Hackaday Prize is still underway, with the Human-Computer Interface Challenge running until August 27th. That will be followed by the Musical Instrument Challenge before the finals spin up. If you haven’t started yet, there’s still time to make your mark. All you need is a documented idea, so start your entry today.

Charging USB-C Devices Off Of LiPo Battery Packs

When it was introduced in the late 90s, USB was the greatest achievement in all of computing. Gone were the PS/2 connectors for keyboards and mice, ADB ports, parallel ports, game ports, and serial ports. This was a Tower of Babel that would unite all ports under one standard universal bus.

Then more ports were introduced; micro, mini, that weird one that was a mini USB with more connectors off to the side. Then we started using phone chargers as power supplies. The Tower of Babel had crumbled. Now, though, there is a future. USB-C is everything stuffed into one port, and it can supply 100 Watts of power.

Delivering power over a USB-C connector is an interesting engineering challenge, and for his Hackaday Prize entry, [Chris Hamilton] is taking up the task. He’s building a USB-C battery charger, allowing him to charge standard R/C battery packs over USB.

There are two major components of the charger. The first, a Cypress CCG2 USB Power Delivery negotiator, handles all the logic of sending a command to the USB power supply and telling it to open up the pipes. It’s an off-the-shelf part and the implementation is well documented in app notes. The second major component is the battery management circuit built on a TI BQ40z60RHB. This includes the charger control logic and the ability to balance up to four cells. Battery connectors are XT-30, so all your drone battery packs can now be charged by a MacBook.

Ultra-Low Power, Energy Harvesting Battery Charger

This half-inch square ultra-low power energy harvesting LiPo cell charger by [Kris Winer] uses a low voltage solar panel to top up a small lithium-polymer cell, which together can be used as the sole power source for projects. It’s handy enough that [Kris] uses them for his own projects and offers them for sale to fellow hackers. It’s also his entry into the Power Harvesting Challenge of the Hackaday Prize.

The board is essentially a breakout board for the Texas Instrument BQ25504, configured to charge and maintain a single lithium-polymer cell. The BQ25504 is an integrated part that takes care of most of the heavy lifting and has nifty features like battery health monitoring and undervoltage protection. [Kris] has been using the board along with a small 2.2 Volt solar panel and a 150 mAh LiPo cell to power another project of his: the SensorTile environmental data logger.

It’s a practical and useful way to test things; he says that an average of 6 hours of direct sunlight daily is just enough to keep the 1.8 mA SensorTile running indefinitely. These are small amounts of power, to be sure, but it’s free and self-sustaining which is just what a remote sensing unit needs.

Battery-Powered Watering Timer Converted to Solar on the Cheap

Watering the garden or the lawn is one of those springtime chores that is way more appealing early in the season than later. As the growing season grinds along, a chore that seemed life-giving and satisfying becomes, well, just another chore, and plants often suffer for it.

Automating the watering task can be as simple as buying a little electronic timer valve that turns on the flow at the appointed times. [A1ronzo] converted his water hose timer to solar power. Most such timers are very similar, with a solenoid-operated pilot valve in line with the water supply and an electronic timer of some sort. The whole thing is quite capable of running on a pair of AA batteries, but rather than wasting money on new batteries several times a season, he slipped a LiPo pack and a charge controller into the battery case slot and connected a small solar panel to the top of the controller.

The LiPo is a nominal 3.7-volt pack, so he did a little testing to make sure the timer would be OK with the higher voltage. The solar panel sits on top of the case, and the whole thing should last for years. And bonus points for never having to replace a timer that you put away at the end of the season with batteries still in it, only to have them leak. Ask us how we know.

Like the best of hacks, this one is quick, easy and cheap — $15 in parts, aside from the timer. There are more complicated irrigation solutions, of course, one of which even won the Hackaday Prize once upon a time. But this one has us ordering parts to build our own right now.