E-paper Price Tags Combined To Create A Large Wireless Display

August 5, 2022 by Danie Conradie 3 Comments

E-paper price tags have become popular for retail stores over the past few years, which is great for hackers since we now have some more cheap commodity hardware to play with. [Aaron Christophel] went all on creating grid displays with E-paper price tags, up to a 20×15 grid.

E-paper price tags are great for these kinds of projects, since they are wireless, lightweight, and can last a long time with the onboard batteries. To mount the individual tags on the plywood backboard,[Aaron] simply glued Velcro to the backboard of the tags. The displays’ firmware is based on the reverse engineering work of [Dmitry Grinberg], flashed to a few hundred tags using a convenient 3D printed pogo pin programming jig. All the displays are controlled via a Zigbee USB dongle plugged into a PC running station software.

[Aaron] is also experimenting with the displays removed from their enclosure and popped into a 3D printed grid frame. The disadvantage is the loss of the battery holders and the antenna, which are both integrated into the enclosure. He plans to get around this by powering the displays from a single large battery, and connecting an ESP32 to the displays via ISP or UART.

This project comes hot on the heels of another E-ink grid display project that uses Bluetooth and a rather clever update scheme.

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The modem in question plugged into a black powerbank.

Hackable $20 Modem Combines LTE And Pi Zero W2 Power

August 3, 2022 by Arya Voronova 188 Comments

[extrowerk] tells us about a new hacker-friendly device – a $20 LTE modem stick with a quadcore CPU and WiFi, capable of running fully-featured Linux distributions. This discovery hinges on a mountain of work by a Chinese hacker [HandsomeYingYan], who’s figured out this stick runs Android, hacked its bootloader, tweaked a Linux kernel for it and created a Debian distribution for the stick – calling this the OpenStick project. [extrowerk]’s writeup translates the [HandsomeYingYan]’s tutorial for us and makes a few more useful notes. With this writeup in hand, we have unlocked a whole new SBC to use in our projects – at a surprisingly low price!

At times when even the simplest Pi Zero is unobtainium (yet again!), this is a wonderful find. For a bit over the price of a Zero 2W, you get a computer with a similar CPU (4-core 1GHz A53-based Qualcomm MSM8916), same amount of RAM, 4GB storage, WiFi – and an LTE modem. You can stick this one into a powerbank or a wallwart and run it at a remote location, make it into a home automation hub, or perhaps, process some CPU-intensive tasks in a small footprint. You can even get them with a microSD slot for extra storage – or perhaps, even extra GPIOs? You’re not getting a soldering-friendly GPIO header, but it has a few LEDs and, apparently, a UART header, so it’s not all bad. As [extrowerk] points out, this is basically a mobile phone in a stick form factor, but without the display and the battery.

Now, there’s caveats. [extrowerk] points out that you should buy the modem with the appropriate LTE bands for your country – and that’s not the only thing to watch out for. A friend of ours recently obtained a visually identical modem; when we got news of this hack, she disassembled it for us – finding out that it was equipped with a far more limited CPU, the MDM9600. That is an LTE modem chip, and its functions are limited to performing USB 4G stick duty with some basic WiFi features. Judging by a popular mobile device reverse-engineering forum’s investigations (Russian, translated), looks like the earlier versions of this modem came with the way more limited MDM9600 SoC, not able to run Linux like the stick we’re interested in does. If you like this modem and understandably want to procure a few, see if you can make sure you’ll get MSM8916 and not the MDM9600.

Days of using WiFi routers to power our robots are long gone since the advent of Raspberry Pi, but we still remember them fondly, and we’re glad to see a router stick with the Pi Zero 2W oomph. We’ve been hacking at such sticks for over half a decade now, most of them OpenWRT-based, some as small as an SD card reader. Now, when SBCs are hard to procure, this could be a perfect fit for one of your next projects.

Update: in the comments below, people have found a few links where you should be able to get one of these modems with the right CPU. Also, [Joe] has started investigating the onboard components!

Toddler EV Gets Big Boy Battery Upgrade

July 29, 2022 by Ryan Flowers 13 Comments

No matter the type of vehicle we drive, it has a battery. Those batteries wear out over time. Even high end EV’s have batteries with a finite life. But when your EV uses Lead Acid batteries, that life is measured on a much shorter scale. This is especially true when the EV is driven by a driver that takes up scarcely more space in their EV than a stuffed tiger toy! Thankfully, the little girl in question has a mechanic:

A 3d printed adapter sends go-juice to the DC-DC converter

Her daddy, [Brian Lough], who documented the swift conversion of his daughter’s toy truck from Lead Acid to Li-Ion in the video which you can see below the break.

Facing challenges similar to that of actual road worthy passenger vehicles, [Brian] teamed up with [bitluni] to solve them. The 12 V SLA battery was being replaced with a 20 V Li-Ion pack from a power tool. A 3d printed adapter was enlisted to break out the power pins on the pack. The excessive voltage was handled with a DC-to-DC converter that, after a bit of tweaking, was putting out a solid 12 V.

What we love about the hack is that it’s one anybody can do, and it gives an inkling of what type of engineering goes into even larger projects. And be sure to watch the video to the end for the adorable and giggly results!

Speaking of larger projects, check out the reverse engineering required in this Lead Acid to Li-Ion conversion we covered in 2016.

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The charging station on the table, with twelve powerbanks plugged into it, charging. A small meter on the front panel shows 4.73 volts and 4.38 amps.

A Simple Charging Station For Twelve Powerbanks

July 25, 2022 by Arya Voronova 13 Comments

[jasonwinfieldnz] uses twelve small powerbanks day to day – powering LED strips around his trampoline, presumably, to avoid the mess of wires and make the assembly easily portable. However, if you have twelve powerbanks, you’ll find yourself hogging all the household’s microUSB cables every so often, as they eventually discharge. This was not good enough for our hacker, and he decided to build a charging station to refill them all at once.

If you need 5 volts and many amps, an ATX PSU isn’t your worst bet. From there, he only had to add twelve microUSB connectors to – and condensed the entire contraption into a beautiful charging station. For the microUSB part, he hacked some microUSB cable ends off and embedded them into the case. An embedded voltage and current module is of big help – letting you see at a glance when charging has really finished. Using copper tape as bus bars and banana plugs for charging input, this project is easy to build and solves the problem well.

The 3D printing files and cutting templates are right there on the project page, so if any of us hackers has a problem that twelve powerbanks could help with, [Jason]’s project is quite repeatable. If your devices are more diverse, you could use a pegboard to build a stylish charging station for them! If, on the other hand, you have a single device you need to plug multiple cords into, moldable plastic is there to help.

A Simple Web-Based Wiring Harness Tool

July 15, 2022 by Dave Rowntree 33 Comments

When building electronic assemblies there is quite often the need to construct custom cables to hook things up. It’s all very well if you’re prototyping by hand, or just building one or two of a thing, but if you’re cranking them out using outside help, then you’re going to want to ensure that cable is described very accurately. [Christian Nimako-Boateng Jr.] presents for us the first version of wirely, a wiring harness tool. This is a web-based tool that allows one to describe the cable ends and connectivity between them, producing a handy graphic and exports to excel in a format that should be easy to follow.

Based around the wireviz Python library running on a flask-based backend, image data are sent to the web assembly front-end and rendered with OpenGL. Configuration files can be imported and exported as JSON, making it easily linkable to other tools if required. Helpfully, the tool also seems to support some kind of revision control, although we didn’t try that yet. The process is straightforward enough, one simply defines a few groups (these relate to individual PCBs or other floating items in the assembly) which each contain one or more connectors. First, the connectors are described with part numbers, and wire gauge data, before defining the list of connections (wires) showing which signal and physical pins are connected together. Nothing more complex than that yet. We think there is still some more functionality that the tool could manage, such as shielding and guarding details, twisted pair definitions and a few others, but for a first pass, wirely looks pretty handy.

If you want a more heavyweight option using IEC 60617 symbols for describing wiring harnesses, then look no farther than QElectroTech, and yes, we have covered wireviz before, just for those that want to cut out the middleman and describe their cables in Python directly.

GCore: Make Portable Devices With Less Frustration

July 9, 2022 by Donald Papp 9 Comments

[Dan Julio]’s gCore (short for Gadget Core) is aimed at making GUI-based portable and rechargeable gadgets much easier to develop. gCore is the result of [Dan]’s own need for a less tiresome way to develop such hardware.

A touchscreen is great, but high-quality power control and charging features are what really make a portable device sing.

[Dan] found that he seemed to always be hacking a lot of extra circuitry into development boards just to get decent power management and charge control. To solve this, he designed his own common hardware platform for portable gadgets and the gCore was born.

While the color touchscreen is an eye-catching and useful addition, the real star of his design is the power management and charging features. Unlike most development hardware, the gCore intelligently shares load power with charging power. Power on and power off are also all under software control.

Sound intriguing? That’s not all the gCore has to offer, and you can learn more from the project page at hackaday.io (which has a more in-depth discussion of the design decisions and concept.) There are also some additional photos and details on [Dan]’s website.

[Dan] is no stranger to developing hardware. The tcam-mini thermal imager (and much more) is his work, and we have no doubt the gCore’s design and features are informed directly by [Dan]’s actual, practical development needs.

Dual Power Supply In A Pinch

July 2, 2022 by Chris Lott 14 Comments

Recently I needed a dual voltage power supply to test a newly-arrived PCB, but my usual beast of a lab power supply was temporarily at a client’s site. I had a FNIRSI programmable power supply which would have been perfect, but alas, I had only one. While digging around in my junk box I found several USB-C power-delivery “trigger” boards which I bought for an upcoming project. These seemed almost too small for the task at hand, but after a little research I realized they would work quite well.

The ones I had used the Injoinic IP2721 USB-C power delivery chip, commonly used in many of these boards. Mine had been sold pre-configured for certain output voltages, but they were easy to re-jumper to the voltages I needed, +5 VDC and +20 VDC. The most challenging aspect was physically using them — they are the size of a fingernail. This version had through-hole output pads on 0.1″ centers, so I decided to solder them to the base of a standard MTA pin header. A few crimps later and I was up and running, along with the requisite pair of USB-C cables and power adapters.

For just a few dollars each, these trigger boards are useful to have in your toolbox, both for individual projects and for use in a pinch. We reviewed these modules a couple of years ago, and check out the far more flexible PD Micro that we covered last year.