Retrotechtacular: Oh Boy! We’re Radio Engineers!

September 6, 2022 by Al Williams 43 Comments

It is a shame that there are fewer and fewer “nerd stores” around. Fry’s is gone. Radio Shack is gone. But the best ones were always the places that had junk. Silicon valley was great for these places, but they were everywhere. Often, they made their money selling parts to the repair trade, but they had a section for people like us. There’s still one of these stores in the Houston, Texas area. One of the two original Electronic Parts Outlets, or EPO. Walking through there is like a museum of old gear and parts and I am not ashamed to confess I sometimes drive the hour from my house just to wander its aisles, needing to buy absolutely nothing. It was on one of those trips that I spied something I hadn’t noticed before. A Remco Caravelle transmitter/receiver.

The box was clearly old and the styling of the radio was decidedly retro. You can tell it wasn’t catering to the modern market because it mentions: “play ham radio operator” which would surely mystify most of today’s kids. The unit was an AM receiver and a transmitter, complete with a morse code key and microphone. You can see a contemporary commercial for a similar unit from Remco, in the video below.

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Tesla’s Dojo Is An Interesting CPU Design

September 6, 2022 by Matthew Carlson 29 Comments

What do you get when you cross a modern super-scalar out-of-order CPU core with more traditional microcontroller aspects such as no virtual memory, no memory cache, and no DDR or PCIe controllers? You get the Tesla Dojo, which Chips and Cheese recently did a deep dive on.

It starts with a comparison to the IBM Cell processors. The Cell of the mid-2000s featured something called the SPE (Synergistic Processing Elements). They were smaller cores focused on vector processing or other specialized types of workloads. They didn’t access the main memory and had to be given tasks by the fully featured CPU. Dojo has 1.25MB of SRAM that it can use as working memory with five ports, but it has no cache or virtual memory. It uses DMA to get the information it needs via a mesh system. The front end pulls RISC-V-like (heavily MIPS-inspired) instructions into a small instruction cache and decodes eight instructions per cycle. Continue reading “Tesla’s Dojo Is An Interesting CPU Design” →

A Simple Web Configured BLE To GPIO Bridge

September 6, 2022 by Dave Rowntree 5 Comments

[Daniel Dakhno] kept ending up in a situation where the ability to read the status of, or control a few digital IO pins with minimal effort, would be terribly useful. Not wanting to keep compiling code, for such simple needs, they instead used a nRF51-based module as a physical interface and produced a general purpose firmware that could be configured with a simple web interface. The NRF51-IO-module was born, whose job is to pair with whatever device you have in front of you, provided it supports BLE, and give direct access to those IO pins.

Rather than acting as a rather slow logic analyser, the firmware is intended for mostly static configurations. The web application sends a configuration packet over to the nRF51 board, which then programs it into FLASH and restarts, reading the updated configuration and applying it to the IO pins. These outputs then persist as long as there is power. The read-side of the equation can also be performed via the web page, but we didn’t have a chance to verify that. The code implements the Bluetooth automation IO service as well as the binary sensor service so if you have access to applications that talk these services, then you should be able to fire it up and go with it, although we’ve not personally tested this due to lack of an nRF51 board. We noticed that the Home Assistant automation platform supports the BT binary sensor, which might be a big help for some people with a need for some wireless control and sensing.

If you need a practical example of a use for remote sensing, here’s a physical mailbox status monitor, using the nRF51. Whilst we’re thinking of Bluetooth and sensors, here’s a custom firmware for some super cheap environment sensors that frees them from vendor lock-in.

Header image: Ubahnverleih, CC0.

Touch Tone MIDI Phone And Vocoder Covers Daft Punk

September 6, 2022 by Donald Papp 3 Comments

[poprhythm]’s Touch Tone MIDI Phone is a fantastic conversion of an old touch tone phone into a MIDI instrument complete with intact microphone, but this project isn’t just about showing off the result. [poprhythm] details everything about how he interfaced to the keypad, how he used that with an Arduino to create a working MIDI interface, and exactly how he decided — musically speaking — what each button should do. The LEDs on the phone are even repurposed to blink happily depending on what is going on, which is a nice touch.

Of course, it doesn’t end there. [poprhythm] also makes use of the microphone in the phone’s handset. Since the phone is now a MIDI instrument with both a microphone and note inputs, it’s possible to use them together as the inputs to vocoder software, which he demonstrates by covering Around the World by Daft Punk (video).

We love how [poprhythm] explains how he interfaced to everything because hardware work is all about such details, and finding the right resources. Here’s the GitHub repository for the Arduino code and a few links to other resources.

We have seen MIDI phone projects before, and each one is always unique in its own way: here’s a different approach to converting a keypad phone to MIDI, and this rotary pulse-dial phone went in a completely different direction with the phone itself completely unmodified, using only external interfacing.

You can admire [poprhythm]’s Touch Tone MIDI Phone in action in the short videos embedded below, with each one showing off a different aspect of the build. It’s great work!

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Hackaday Prize 2022: DIY Landslide Warning System

September 6, 2022 by Lewin Day 4 Comments

Landslides can be highly dangerous to both people and property. As with most natural disasters, early warning can make all the difference. [Airpocket] has built a cheap, affordable system that hopes to offer just that.

The system relies on a network of sensors built with Sony Spresense controllers, built into solar garden light enclosures which provide a watertight enclosure and a sustainable power supply. The controllers are paired with accelerometers to detect movement, and communicate over a WiSUN connection back to a Raspberry Pi 4B base station. When a deployed sensor station detects movement, it sends a message back to the base station, which sounds the alarm that a landslide may be imminent.

Early testing shows the concept works in theory. In practice, some improvements to reduce power draw and increase communication reliability are required. However, it’s a solid proof of concept for a simple landslide warning system.

Early warning is always key when it comes to things like landslides, tsunamis, and earthquakes. In fact, the US Geological Survey has done its own work on predicting earthquakes and providing early warning, too. Video after the break.

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Lithium-Ion Batteries Are Your Friends

September 6, 2022 by Arya Voronova 56 Comments

Need some kind of battery for a project? You can always find a few Lithium-Ion (LiIon) batteries around! They’re in our phones, laptops, and a myriad other battery-powered things of all forms – as hackers, we will find ourselves working with them more and more. Lithium-Ion batteries are unmatched when it comes to energy capacity, ease of charging, and all the shapes and sizes you can get one in.

There’s also misconceptions about these batteries – bad advice floating around, fearmongering videos of devices ablaze, as well as mundane lack of understanding. Today, I’d like to provide a general overview of how to treat your LiIon batteries properly, making sure they serve you well long-term.

What’s A Battery? A Malleable Pile Of Cells

Lithium-Ion batteries are our friends. Now, there can’t be a proper friendship if you two don’t understand each other. Lithium-Ion batteries are tailored for human needs by the factory that produced them. As for us hackers, we’ll want to learn some things.

First thing to learn – a single LiIon “unit” is called a cell. An average laptop contains three or six Li-Ion cells, a phone will have one, a tablet will have from one to three. What we refer to as “battery” is typically one or multiple cells, together with protection circuitry, casing and a separate connector – most of the time all three of these, but not always. The typical voltage is 3.6 V or 3.7 V, with maximum voltage being 4.2 V – these are chemistry-defined, the same for most kinds of cells and almost always written on the cell. Continue reading “Lithium-Ion Batteries Are Your Friends” →

2022 Hackaday Prize: Save The World Wildcard Challenge Begins Now

September 6, 2022 by Kristina Panos 13 Comments

Continuing the concept of saving planet Earth with gnarly, repeatable hacks, the fifth and final challenge of the 2022 Hackaday Prize is all about making the world better with smart and sustainable hardware. While the focus is still on saving the planet, this time, anything goes. Does your project not fit within the confines of a previous challenge? Here is your last chance to enter the 2022 Hackaday Prize: Start your entry today!

Go Wild!

We’ve already run contest rounds that focused on green power generation, recycling, hacking tech out of the landfills, and just finished up making our world more climate-resistant and connected. How else do you want to use your hacking powers to make the world a better place? Well, that’s up to you. This is the wildcard round, after all. If your project helps to keep this planet running for future generations, you can enter it here.

The Save the World Wildcard challenge starts right now and runs until October 16th. As with previous rounds, we’ll award one of ten $500 prizes to each finalist, and the best projects will have a chance at the overall 2022 Hackaday Prize. So get hacking!