A lot of hams like to carry a VHF radio. Of course, nearly everyone wants to carry a phone. Now, thanks to the kv4p HT, you don’t have to carry both. The open-source device connects to your Android smartphone and turns it into a radio transceiver. You can build it yourself for about $35. Check out the video below.
The device uses an ESP32 and only transmits one watt, but it has lots of features like APRS and scanning.
We really like PCB-level hacks, especially ones that show ingenuity in solving a real problem while being super cheap to implement. Hackaday.IO user [Steph] wanted a cheap way to switch a wearable on and off without having to keep popping out the battery, so they came up with a tweaked battery footprint, which is also a simple slide switch.
Most people making badges and wearables will follow the same well-trodden path of just yanking out the cell or placing some cheap switch down and swallowing the additional cost. For [Steph], the solution was obvious. By taking a standard surface-mount CR2032 button cell holder footprint, extending its courtyard vertically, and moving the negative pad up a smidge, the battery can be simply slid up to engage the pad and slid down to disengage and shut off the juice. The spring section of the positive terminal keeps enough pressure on the battery to prevent it from sliding out, but if you are worried, you can always add a dummy pad at the bottom, as well as a little solder bump to add a bit more security.
Now, why didn’t we think of this before? The KiCad footprint file can be downloaded from the project GitHub page, imported into your project and used straight away.
Many of our gadgets are powered by CR2032 cells—so many so that eliminating the need for them leads to interesting projects, like this sweet USB-powered CR2032 eliminator. But how far can you push the humble cell? Well, we held a contest a few years ago to find out!
I recently got one of the new RP2040-based Bus Pirate 5 (BP5), a multi-purpose interface debugging and testing tool. Scanning the various such tools in my toolbox already: an Analog Discovery 2, a new Glasgow Interface Explorer, and a couple of pyboards, I realized they all had a Python or MicroPython user interface. A few people on the BP5 forums had tossed around the idea of MicroPython, and it just so happened that I was experimenting with building beta versions of MicroPython for a RP2350 board at the time. Naturally, I started wondering, “just how hard can it be to get MicroPython running on the BP5?”
Rather than duplicating the BP5 firmware functionality, I decided to ignore it completely and go with existing MicroPython capabilities. I planned to just make a simple set of board definition files — perhaps Board Support Package (BSP) is a better term? I’ve done this a dozen times before for development and custom boards. Then write a collection of MicroPython modules to conform to the unique aspects in the BP5 hardware. As user [torwag] over on the Bus Pirate forums said back in March:
Micropython comes already with some modules and enough functions to get some stuff out-of-the-box working. E.g. the infamous version of “hello world” for microcontrollers aka led-blinking.
Continue reading “Experimenting With MicroPython On The Bus Pirate 5”
Compared to the human brain, a fruit fly (Drosophila melanogaster) brain is positively miniscule, not only in sheer volume, but also with a mere 140,000 or so neurons and 50 million synapses. Despite this relative simplicity, figuring out how the brain of such a tiny fly works is still an ongoing process. Recently a big leap forward was made thanks to crowdsourced research, resulting in the FlyWire connectome map. Starting with high-resolution electron microscope data, the connections between the individual neurons (the connectome) was painstakingly pieced together, also using computer algorithms, but with validation by a large group of human volunteers using a game-like platform called EyeWire to perform said validation.
This work also includes identifying cell types, with over 8,000 different cell types identified. Within the full connectome subcircuits were identified, as part of an effort to create an ‘effectome’, i.e. a functional model of the physical circuits. With the finished adult female fruit fly connectome in hand, groups of researchers can now use it to make predictions and put these circuits alongside experimental contexts to connect activity in specific parts of the connectome to specific behavior of these flies.
Perhaps most interesting is how creating a game-like environment made the tedious work of reverse-engineering the brain wiring into something that the average person could help with, drastically cutting back the time required to create this connectome. Perhaps that crowdsourced research can also help with the ongoing process to map the human brain, even if that ups the scale of the dataset by many factors. Until we learn more, at this point even comprehending a fruit fly’s brain may conceivably give us many hints which could speed up understanding the human brain.
Featured image: “Drosophila Melanogaster Proboscis” by [Sanjay Acharya]
More than a couple folks have written us saying that their entries into the Supercon Add-On Contest got caught up in the Chinese fall holidays. Add to that our tendency to wait until the last minute, and there still more projects out there that we’d like to see. So we’re extending the deadline one more week, until October 22nd.
If you’re just tuning in now, well, you’ve got some catching up to do. Supercon Add-Ons are another step forward in the tradition of renaming the original SAO. One of our favorite resources on the subject comes from prolific SAO designer [Twinkle Twinkie], and you can even download PCB footprints over there on Hackaday.io.
Don’t know why you want to make an SAO? Even if you’re not coming to Supercon this year? Well, our own [Tom Nardi] describes it as a low barrier to entry, full-stack hardware design and production tutorial. Plus, you’ll have something to trade with like-minded hardware nerds at the next con you attend.
We’ve already seen some killer artistic entries, but we want to see yours! We know the time’s tight, but you can still get in a last minute board run if you get started today. And those of you who are sitting at home waiting for boards to arrive, wipe that sweat from your brow. We’ll catch up with you next Tuesday!
Embedded programming is a tricky task that looks straightforward to the uninitiated, but those with a few decades of experience know differently. Getting what you want to work predictably or even fit into the target can be challenging. When you get to a certain level of complexity, breaking code down into multiple tasks can become necessary, and then most of us will reach for a real-time operating system (RTOS), and the real fun begins. [Aleksei Tertychnyi] clearly understands such issues but instead came up with an alternative they call ANTIRTOS.
The idea behind the project is not to use an RTOS at all but to manage tasks deterministically by utilizing multiple queues of function pointers. The work results in an ultra-lightweight task management library targeting embedded platforms, whether Arduino-based or otherwise. It’s pure C++, so it generally doesn’t matter. The emphasis is on rapid interrupt response, which is, we know, critical to a good embedded design. Implemented as a single header file that is less than 350 lines long, it is not hard to understand (provided you know C++ templates!) and easy to extend to add needed features as they arise. A small code base also makes debugging easier. A vital point of the project is the management of delay routines. Instead of a plain delay(), you write a custom version that executes your short execution task queue, so no time is wasted. Of course, you have to plan how the tasks are grouped and scheduled and all the data flow issues, but that’s all the stuff you’d be doing anyway.
The GitHub project page has some clear examples and is the place to grab that header file to try it yourself. When you really need an RTOS, you have a lot of choices, mostly costing money, but here’s our guide to two popular open source projects: FreeRTOS and ChibiOS. Sometimes, an RTOS isn’t enough, so we design our own full OS from scratch — sort of.
[bitluni] seems rather fond of soldering lots of LEDs, and fortunately for us the result is always interesting eye candy. The latest iteration of this venture features 8 mm WS2812D-F8 addressable LEDs, offering a significant simplification in electronics and the potential for much brighter displays.
The previous version used off-the-shelf 8×8 LED panels but had to be multiplexed, limiting brightness, and required a more complex driver circuit. To control the panel, [bitluni] used the ATtiny running the MegaTinyCore Arduino core. Off-the-shelf four-pin magnetic connectors allow the panels to snap together. They work well but are comically difficult to solder since they keep grabbing the soldering iron. [bitluni] also created a simple battery module and 3D printed neat enclosures for everything.
Having faced the arduous task of fixing individual LEDs on massive LED walls in the past, [bitluni] experimented with staggered holes that allow through-hole LEDs to be plugged in without soldering. Unfortunately, with long leads protruding from the back of the PCB, shorting became an immediate issue. While he ultimately resorted to soldering them for reliability, we’re intrigued by the potential of refining this pluggable design.
The final product snapped together satisfyingly, and [bitluni] programmed a simple animation scheme that automatically updates as panels are added or removed. What would you use these for? Let us know in the comments below. Continue reading “Modular Magnetic LED Matrix”
