Building A Serial Bus To Save An Old Hard Drive

June 28, 2022 by Bryan Cockfield 67 Comments

Universal Serial Bus has been the de facto standard for sending information to and from computer peripherals for almost two decades, but despite the word “universal” in the name this wasn’t always the case. Plenty of competing standards, including USB, existed in the computing world in the decades before it came to dominance, and if you’re trying to recover data from a computer without USB you might have to get creative with how it’s done.

[Ben] recently came across a 80486 with this problem, so he had to get creative to recover the contents of the drive. He calls it the “lunchbox” computer due to its form factor, and while it doesn’t have USB it does have a tried-and-trusted serial port to communicate with other computers. [Ben] wrote up a piece of software for both the receiving computer and the sending computer in order to copy the drive sectors one by one across a serial link to a standalone computer running Windows XP, and was able to recover the contents of the drive that way instead.

All of the code [Ben] wrote is available on his GitHub page for anyone looking to boot up a 30-year-old computer again. While it might sound uncommon, computers of this vintage are still around running things like CNC machines or old mainframes.

Electronic Catan Game Board Is Modular

May 27, 2022 by Bryan Cockfield 6 Comments

Plenty of gamers around these parts require an expensive PC to play games, often spending thousands of dollars for a gaming machine. Believe it or not, though, there are entire classes of games that don’t require any electronics at all, but that doesn’t mean that they don’t benefit from the addition of some neat gadgets. This Settlers of Catan game uses custom LCD tiles with a built-in custom mesh network.

The tiles for the game board themselves are hexagonal and snap together using magnetic pogo pins in order to form a board of any size or shape. The pogo pins also allow communication for a pseudo-mesh network to operate with each tile’s built-in PCB to allow the game board to know exactly which tiles are placed where and to display the correct image on each one. Each tile contains it own RP2040 microcontroller, keeping the overall cost of each tile to a minimum.

For those regularly hosting game night, a project like this could really change the traditionally analog game’s dynamic for the better. It was mostly a project that [Colin Iuliano] built just for fun, and if he ever builds a second one he does plan on some improvements, but we’d say that it looks like a success already. For other Catan-based electronic design inspiration, take a look at this complete and non-modular electronic game board.

Long-Distance Text Communication With LoRa

May 25, 2022 by Bryan Cockfield 50 Comments

Affordable and reliable cell phones have revolutionized the way we communicate over the last two decades or so, and this change was only accelerated by the adoption of the smartphone. This is all well and good if you’re living in a place with cellular infrastructure, but if you’re in more remote areas you’ll have to be a little more inventive. This text-based communications device, for example, lets you send text messages without all of that cumbersome infrastructure.

While [Arthur] didn’t create this project specifically for off-grid use, it’s an interesting project nonetheless. The devices use a physical QWERTY keyboard and a small screen, reminiscent of BlackBerry devices from the late 2000s (partially because they are actually using BlackBerry keyboards). One of the other goals for this project was low power consumption, and between polling the keyboard, the memory LCDs, and receiving and transmitting messages using LoRa, [Arthur] was able to get the current draw down to 12 mA.

Between the relatively common nRF52840 and SX1262 chips, plus the fact that [Arthur] made the schematics available, this makes for an excellent off-grid device for anyone who likes to drive off into the wilderness or lives far enough outside of town that cell phone reception is a concern.

Looking for something a little easier to put together before your upcoming camping trip? This similarly styled LoRa communicator from [MSG] uses off-the-shelf modules to greatly reduce the part count. Another option for off-grid communications is to use existing smartphones paired with a LoRa network like we saw in this project.

I2C To The Max With ATtiny

January 18, 2022 by Bryan Cockfield 28 Comments

The Arduino is a powerful platform for interfacing with the real world, but it isn’t without limits. One of those hard limits, even for the Arduino MEGA, is a finite number of pins that the microcontroller can use to interface with the real world. If you’re looking to extend the platform’s reach in one of your own projects, though, there are a couple of options available. This project from [Bill] shows us one of those options by using the ATtiny85 to offload some of an Arduino’s tasks using I2C.

I2C has been around since the early 80s as a way for microcontrollers to communicate with each other using a minimum of hardware. All that is needed is to connect the I2C pins of the microcontrollers and provide each with power. This project uses an Arduino as the controller and an arbitrary number of smaller ATtiny85 microcontrollers as targets. Communicating with the smaller device allows the Arduino to focus on more processor-intensive tasks while giving the simpler tasks to the ATtiny. It also greatly simplifies wiring for projects that may be distributed across a distance. [Bill] also standardizes the build with a custom development board for the ATtiny that can also double as a shield for the Arduino, allowing him to easily expand and modify his projects without too much extra soldering.

Using I2C might not be the most novel of innovations, but making it easy to use is certainly a valuable tool to add to the toolbox when limited on GPIO or by other physical constraints. To that end, [Bill] also includes code for an example project that simplifies the setup of one of these devices on the software end as well. If you’re looking for some examples for what to do with I2C, take a look at this thermometer that communicates with I2C or this project which uses multiple sensors daisy-chained together.

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Send Old-Fashioned Pager Messages With New-Fashioned Hardware

May 18, 2021 by Bryan Cockfield 5 Comments

In a world of always-connected devices and 24/7 access to email and various social media and messaging platforms, it’s sometimes a good idea to take a step away from the hustle and bustle for peace of mind. But not too big of a step. After all, we sometimes need some limited contact with other humans, so that’s what [EverestX] set out to do with his modern, pocket-sized communication device based on pager technology from days of yore.

The device uses the POCSAG communications protocol, a current standard for pager communications that allows for an SMS-like experience for those still who still need (or want) to use pagers. [EverestX] was able to adapt some preexisting code and port it to an Atmel 32u4 microcontroller. With a custom PCB, small battery, an antenna, and some incredibly refined soldering skills, he was able to put together this build with an incredibly small footprint, slightly larger than a bottle cap.

Once added to a custom case, [EverestX] has an excellent platform for sending pager messages to all of his friends and can avoid any dreaded voice conversations. Pager hacks have been a favorite around these parts for years, and are still a viable option for modern communications needs despite also being a nostalgic relic of decades past. As an added bonus, the 32u4 microcontroller has some interesting non-pager features that you might want to check out as well.

Thanks to [ch0l0man] for the tip!

Custom Dummy Load With Data Logging

March 15, 2021 by Bryan Cockfield 10 Comments

While it might seem counterintuitive on the surface, there are a number of cases where dumping a large amount of energy into a resistor simply to turn it into heat is necessary to the operation of a circuit. Most of these cases involve testing electronic equipment such as power supplies or radio transmitters and while a simple resistor bank can be used in some situations, this active dummy load is comprised of different internals has some extra features to boot.

The load bank built by [Debraj] is actually an electronic load, which opens it up for a wider set of use cases than a simple passive dummy load like a resistor bank. It’s specifically designed for DC and also includes voltage measurement, current control, and temperature measurement and speed control of the fans on the heat sinks. It also includes a Bluetooth module that allows it to communicate to a computer using python via a custom protocol and GUI.

While this one does use a case and some other parts from another product and was specifically built to use them, the PCB schematics and code are all available to build your own or expand on this design. It’s intended for DC applications, but there are other dummy loads available for things such radio antenna design, and it turns out that you can learn a lot from them too.

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IRC Over LoRa, For When Things Really Go South

December 12, 2020 by Tom Nardi 74 Comments

As a society, we’ve become accustomed to always-on high-speed data connections, whether we’re at home on the computer or out and about with a mobile device. But what happens if a natural disaster knocks out the local infrastructure? Sure some people will be able to fire up their radio if they need to reach out and touch someone, but even among hackers, hams are a minority. What we really need is a backup Internet.

The team behind the CellSol project hopes to show that building a volunteer-operated distributed communications network is not only within the capabilities of the hacker community but probably much easier and cheaper to do than you might think. Each node in the network, known as a Pylon in CellSol parlance, can shuttle data between the LoRa backbone and WiFi-enabled devices like smartphones and computers. Once the network is up and running, users don’t need any special hardware or software to use it.

Now to be clear, nobody is talking about surfing the web here. When a user connects to one of the ESP32 Pylons, they’ll be able to access a simplistic chat system through their browser. If the Pylon has an active Internet connection the chat can be bridged to an IRC channel. Without Internet connectivity, the pylon will simply give users on the CellSol network a means to communicate among each other. To keep things simple there’s no user names, private messages, or encryption. This is bare-bones, end-of-the-world style communication.

Want to join the CellSol revolution? All you really need is an ESP32, a LoRa radio, and the open-source firmware. If you get something like the Heltec LoRa 32 development board, you don’t even need to solder anything together. Just flash the board and go. Once you have a few Pylons going, you can also put together a cheap repeater node using a LoRa equipped Arduino. Both devices are small and energy efficient enough that they could easily be battery or solar powered. As you can see in the video after the break, the team even envisions a future where they could be dropped off in public areas via drone.

This isn’t the first time we’ve seen the ESP32 used to establish an off-grid LoRa communications network, and like those previous attempts, it’s usefulness will largely depend on how many people you can convince to set up their own nodes and repeaters. But if you’ve got some open minded friends who live relatively close by, this could be a great way to have a little chat.

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