Rescuing High-Res Displays From Older Macs

When Apple started rolling out its Retina displays, it multiplied the amount of pixels compared to their standard, non-Retina displays by four. This increased pixel density while keeping the standard screen size — idea for those needing a lot of detail for their work. But, as is common with Apple, using these displays outside of the Apple ecosystem can be quite a challenge. Retina displays have been around for about a decade now, though, with some third-party hardware able to break them free of their cage. This post details how [Kevin] liberated the 5K display from a 2017 iMac for more general use with support for USB-C.

The first step was to find a used iMac for the right price, and then sell off most of its parts to recoup most of the initial cost. That brought the cost of the panel itself to about $250. The key to getting the display working without all of the Apple hardware is the R1811 driver board, which can be had for around $300. A new 156 watt power supply was added to the mix, and [Kevin] also put in a few extras like a USB cable extension and a latching push-button which kills the display’s power. Additionally, he attempted to get the original iMac speakers working with this setup too, but none of his attempts resulted in anything close to quality sound so he’s mostly abandoned that extra feature for now.

With that all buttoned up, he has a 27″ 5K display with USB-C input for around $650 which is quite a deal. The MacRumors thread that [Kevin] added his project to currently has around 1,700 posts about similar builds too, so it can be a wealth of information for all kinds of models. As Apple drops support for their older machines, these displays will become more and more common and projects like these can keep a lot of e-waste out of the landfill while also providing decent hardware at a bargain price. Don’t just look for iMacs and MacBooks though; there’s a similar process to use various iPad displays for other things as well.

Universal Power Bank Customized To Your Liking

One of the most troubling trends of almost every modern consumer product that uses electricity is that the software that controls the product is likely to be proprietary and closed-source, which could be doing (or not doing) any number of things that its owner has no control over. Whether it’s a computer, kitchen appliance, or even a device that handles the electricity directly, it’s fairly rare to find something with software that’s open and customizable. That’s why [Traditional-Code9728] is working on a power bank with an open-source firmware.

From a hardware perspective the power bank is fairly open as well, with a number of options for connecting this device to anything else that might need power. It sports a bidirectional USB-C port as well as a DC barrel plug, either of which can either charge other devices or receive energy to charge its own battery. These ports can also accept energy from a solar panel and have MPPT built in. There’s also dual USB-A ports which can provide anywhere from five to 12 volts at 25 watts, and a color screen which shows the current status of the device.

While this is a prototype device, it’s still actively being worked on. Some future planned upgrades to the power bank include a slimmer design, charge limiting features to improve battery life, and more fine-tuned control of the output voltage and current on the USB-C port. With all of the software being open-source, as well as the circuit diagram and 3D printing files, it could find itself in plenty of applications as well. This power bank also stays under the energy limits for flying on most commercial airlines as well, but if you don’t plan on taking your power bank on an airplane then you might want to try out this 2000-watt monster instead.

USB-C Powered Hotplate Is Not For Food

Once upon a time, it was deemed mostly silly to try and schlep power from a computer’s ports. Then it was kind of amusing to do so with USB, and before you knew it, we were running whole laptops off what started out as a data connector. These days, it’s not unusual to run a soldering iron off USB-C, or, as [MarkTheQuasiEngineer] has done—a hotplate!

This hotplate is not for quesadillas, nor samosas. Instead, it’s a tiny hotplate for tiny reflow tasks. Given many PCBs are quite small, there’s no need for a huge hot plate to get your circuits assembled.

The device relies on metal ceramic heating elements to provide the warmth. An NTC thermistor is used for monitoring the temperature for accurate control, which is handled by the STM32 microcontroller that’s running the show. It also drives a small display indicating the mode of operation and current temperature. The STM32 controls the power going to the heating element from the USB-C feed with a stout power MOSFET.

Sadly, the project hasn’t been a complete success. With a PCB on the plate, [MarkTheQuasiEngineer] was only able to achieve peak temperatures of around 200 C. That’s not great for doing proper reflow, but it’s a start. He believes upgrading to a more powerful supply to feed the hotplate will help.

We’ve featured some other great reflow hotplates before too.
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A devboard with the CH32V003, with a few resistors and bodges, with a USB-C cable plugged into it, and a programmer plus an extra probe attached.

USB PD On CH32V003 Teaches You Everything

How do you talk USB Power Delivery (PD)? Grab a PHY? Use a MCU with one built-in? Well, if you’re hardcore enough, you can do it with just a few resistors and GPIOs. [eeucalyptus] shows you their implementation of USB-PD on a CH32V003, which has no PD peripheral. This includes building a PD trigger, completely open source, and walking you through the entire low-level PD basics, too!

It helps that CH32V003 is a 32-bit MCU with a good few resources and peripherals, for instance, an internal comparator. Other than that, you don’t need much in terms of hardware resources, but you do need a steady hand — parts of the firmware had to be written in assembly to keep up with PD timing. Want to tinker with the fruit of this research, perhaps, further build upon the code? There’s an example board on GitHub, too!

Want to try your own luck with this method? There’s a schematic, and logic analyzer captures, and a board to refer to. Again, more than enough information on every single low-level detail! Otherwise, grab an MCU pre-programmed to talk PD, maybe a trigger board chip, or maybe even a PD PHY and implement PD communications with it directly – it’s pretty easy!

We thank [Julianna] for sharing this with us!

The splitter with a 3D-printed case and three yellow cables coming out of it, powering two phones and one powerbank at the same time

Split A USB-C PD Port Into Three Port-ions

There’s no shortage of USB-C chargers in all sorts of configurations, but sometimes, you simply need a few more charging ports on the go, and you got a single one. Well then, check out [bluepylons]’s USB-C splitter, which takes a single USB-C 5V/3A port and splits it into three 5V/1A plugs, wonderful for charging a good few devices on the go!

This adapter does things right – it actually checks that 3A is provided, with just a comparator, and uses that to switch power to the three outputs, correctly signalling to the consumer devices that they may consume about 1A from the plugs. This hack’s documentation is super considerate – you get detailed instructions on how to reproduce it, every nuance you might want to keep in mind, and even different case options depending on whether you want to pot the case or instead use a thermal pad for a specific component which might have to dissipate some heat during operation!

This hack has been documented with notable care for whoever might want to walk the journey of building one for themselves, so if you ever need a splitter, this one is a wonderful weekend project you are sure to complete. Wonder what kind of project would be a polar opposite, but in all the best ways? Why, this 2kW USB-PD PSU, most certainly.

Soldering The Elusive USB C Port

Many SMD components, including some USB C ports, have their terminals under the component. When installed, the pins are totally hidden. So, how do you solder or unsolder them? That’s the problem [Learn Electronics Repair] encountered when fixing a Lenovo Yoga, and he shows us his solution in the video below.

He showed the removal in a previous video, but removal is a bit easier since you can just heat up the area, yank the connector, and then clean up the resulting mess at your leisure. Installation is harder because once the socket is down, you no longer have access to the pads.

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Designing A USB-C Upgrade PCB For The MX Ergo Mouse

As the world of electronic gadgetry made the switch from micro USB to USB-C as the charging port of choice, many of us kept both of the required cables handy. But it’s fair to say that these days a micro USB port has become a pretty rare sight, and the once ubiquitous cable can be a bit elusive in the event that you encounter an older device that requires it.

[Solderking] has a high-end Logitech cordless mouse with just this problem, and so he replaced its micro USB socket with a USB-C port. That makes the task sound deceptively simple, because in fact he had to reverse engineer one of the device’s PCBs in its entirety, making a new board with the same outline and components, but sporting the new connector.

Instead of attempting to replicate the complex shape with geometry he started with a scan of the board and had Fusion 360 trace its outline before 3D printing a version of it to check fit in the Logitech case. Then it was a case of tracing the circuit, designing the replacement, and hand transferring the parts from board to board.

The result is a USB-C chargeable mouse, and while all the design files don’t appear to be online, it’s possible to download the Gerbers from a PCBWay page. On top of that there’s a YouTube video of the process which we’ve placed below the break.

This isn’t the first time we’ve seen somebody spin up a new board to add USB-C to an older device — this drop-in replacement for Sony’s DualShock 4 comes to mind. If you’ve got enough free space inside your particular gadget, you might be able to pull of a USB-C conversion with nothing more exotic than a hacked up Adafruit breakout board.

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