Wireless All The Things!

February 17, 2024 by Elliot Williams 48 Comments

Neither Tom Nardi nor I are exactly young anymore, and we can both remember a time when joysticks were actually connected with wires to the computer or console, for instance. Back then, even though wireless options were on the market, you’d still want the wired version if it was a reaction-speed game, because wireless links just used to be too slow.

Somehow, in the intervening years, and although we never even really noticed the transition as such, everything has become wireless. And that includes our own hacker projects. Sure, the ESP8266 and other WiFi-capable chips made a big difference, but I still have a soft spot in my heart for the nRF24 chipset, which made at least point-to-point wireless affordable and easy. Others will feel the same about ZigBee, but the point stands: nothing has wires anymore, except to charge back up.

The reason? As this experiment comparing the latency of many different wireless connections bears out, wireless data links have just gotten that good, to the point that the latency in the radio is on par with what you’d get over USB. And the relevant software ecosystems have made it easier to go wireless as well. Except for the extra power requirement, and for cases where you need to move a lot of data, there’s almost no reason that any of your devices need wires anymore.

Are you with us? Will you throw down your chains and go wireless?

Gyro-Controlled Labyrinth Game Outputs To VGA

January 3, 2024 by Donald Papp 4 Comments

This gesture-controlled labyrinth game using two Raspberry Pi Pico units does a great job of demonstrating how it can sometimes take a lot of work to make something look simple.

To play, one tilts an MPU6050 inertial measurement unit (IMU) attached to one Pico to guide a square through a 2D maze, with the player working through multiple levels of difficulty. A second Pico takes care of displaying the game state on a VGA monitor, and together they work wirelessly to deliver a coherent experience with the right “feel”. This includes low latency, simulating friction appropriately, and more.

Taking a stream of raw sensor readings and turning them into control instructions over UDP in a way that feels intuitive while at the same time generating a VGA display signal has a lot of moving parts, software-wise. The project write-up has a considerable amount of detail on the architecture of the system, and the source code is available on GitHub for those who want a closer look.

We’ve seen gesture controls interfaced to physical marble mazes before, but two Raspberry Pi Picos doing it wirelessly with a VGA monitor for feedback is pretty neat. Watch it in action in the video, embedded just under the page break.

Continue reading “Gyro-Controlled Labyrinth Game Outputs To VGA” →

One Less Binary Blob

December 7, 2023 by Bryan Cockfield 36 Comments

Open-source software has gone a long way into making modern technology the way it is today. The Linux kernel alone is almost single-handedly holding up the entire Internet, and various other open-source projects allow for more access to computing resources not just because the software is often free, but because it’s possible to look under the hood and modify it for specific needs. Without open-source software available we often run into problems both expected, such as software licensing costs, and unexpected, which often come up because a developer can’t or won’t fix issues or add features. To that end, a group at Ghent University in Belgium are attempting to rectify a problem with the ESP32 by eliminating one of its binary blobs and replacing it with an open source driver.

The ESP32 is famously a low-cost microcontroller with on-board wireless capabilities, but its Wi-Fi functionality currently relies on closed-source software from Espressif. The team is currently working on building a fully working open-source networking stack with the hopes of enabling greater flexibility of these devices but also making things like security auditing possible. The other major goal is to improve low-cost mesh networking which is currently not available with the proprietary driver. Reverse engineering is the name of the game here, both from a hardware and a software level, but current versions of the software already able to send and receive packets.

The source code for the project is available on the team’s GitHub page for any open-source aficionados to take a look at. We certainly hope the project gains some steam, as any new open source project helps all of us using the platform. Open source projects frequently get stymied by a single or small handful of binary blobs too, often with little hope for recourse. Examples include Android being an open-source operating system but generally using the closed-source Google Play suite in practice, or Firefox including support for Adobe Flash. Another great example is that even computers running 100% open-source code once they boot their operating systems, there’s still some black boxes running in the background few of us think about.

Thanks to [Crote] for the tip!

Wireless Data Connections Through Light

August 25, 2023 by Bryan Cockfield 38 Comments

When wired networking or data connections can’t be made, for reasons of distance or practicality, various wireless protocols are available to us. Wi-Fi is among the most common, at least as far as networking personal computers is concerned, but other methods such as LoRa or Zigbee are available when data rates are low and distances great. All of these methods share one thing in common, though: their use of radio waves to send data. Using other parts of the electromagnetic spectrum is not out of the question, though, and [mircemk] demonstrates using light as the medium instead of radio.

Although this isn’t a new technology (“Li-Fi” was first introduced in 2011) it’s not one that we see often. It does have a few benefits though, including high rates of data transmission. In this system, [mircemk] is using an LED to send the information and a solar cell as the receiver. The LED is connected to a simple analog modulator circuit, which takes an audio signal as its input and sends the data to the light. The solar cell sends its data, with the help of a capacitor, straight to the aux input on a radio which is used to convert the signal back to audio.

Some of the other perks of a system like this are seen here as well. The audio is clear even as the light source and solar cell are separated at a fairly significant distance, perhaps ten meters or so. This might not seem like a lot compared to Wi-Fi, but another perk shown is that this method can be used within existing lighting systems since the modulation is not detectable by the human eye. Outside of a home or office setting, systems like these can also be used to send data much greater distances as well, as long as the LED is replaced with a laser.

Continue reading “Wireless Data Connections Through Light” →

Open Source OLED Nametag Is Full Of Features

July 20, 2023 by Donald Papp 5 Comments

Ever wanted a sweet OLED nametag with fancy features like daylight readability, automatic brightness adjustment, GIF animation support, all-day runtime, easy web interface, and more? [TobleMiner]’s OLED Nametag is the project you want to keep an eye on in that case.

It’s still an early prototype, but the feature list looks great and works with a variety of OLED modules that are easily available. The enclosure can be 3D printed, and while there is very little spare room inside the housing, [TobleMiner] has clearly made the most of all available space. Some PCB fab houses offer component placement these days, and the board is designed with exactly that in mind.

We’ve seen a batteryless E-paper display make a serviceable nametag in the past, and while those offer high contrast and wide viewing angles, they lack the sort of features this project is bursting at the seams with. Affordable access to good components and the ability to have high-quality PCBs made on demand has really raised the bar in terms of what a hacker project can work with in recent years, and we love to see it expressed in projects like this one.

Souped-Up Reflective Sensor Uses Itself For Wireless Programming

June 6, 2023 by Dan Maloney 4 Comments

Proximity sensors are common enough in automation projects that we hardly give them a second thought — pick something with specs that match the job and move on. But they can be fussy to get adjusted just right, a job made more difficult if they’re located in some out-of-the-way corner.

But where lies a challenge, there’s also an opportunity, as [Ido Gendel] shows us with this remote-controlled proximity sensor. The story behind this clever little hack starts with an off-the-shelf sensor, the kind with an IR LED and a phototransistor pointed in the same direction that gives a digital output when the light bouncing back into the phototransistor exceeds a certain threshold. It was setting the threshold that gave [Ido]’s client trouble, so [Ido] decided to build a programmable drop-in replacement to make the job easier.

The first try at this used an OBP732 reflective transmitter and an ATtiny202 microcontroller and had three pads on the PCB for programming. This still required physical contact for programming, though, so [Ido] had the idea to use the sensor for wireless IR programming. The microcontroller on version two was switched to an ATtiny212, and a couple of components were added to control the power of the LED so the sensor could do double duty. A programmer using the same sensor and a USB-to-UART adapter completes the system, and allows the sensor threshold to be set just by shining the programmer in its general direction from up to 25 cm away.

We think that getting multiple uses from a single sensor is pretty clever, so hats off for this one. It’s not the first time we’ve featured one of [Ido]’s projects, but it’s been quite a while — this one-clock-cycle-a-day Shabbat clock was the most recent, but you can clearly see the roots of the sensor project in this mouse pointer data encoder that goes all the way back to 2015.

Headset’s Poor Range Fixed By Replacing Antenna

May 27, 2023 by Donald Papp 14 Comments

[rafii6312]’s Corsair HS80 wireless headset had a big problem: short range. The sound quality was great, but the wireless range wasn’t winning any friends. Fortunately, the solution was just to swap the small SMT antenna on the USB transmitter for an external one.

Original SMT antenna (blue component) offers small size, but poor range.

This particular headset relies on a USB dongle to transmit audio from PC to headset over its own 2.4 GHz wireless connection. By popping open the USB dongle, [rafii6312] was able to identify an SMT antenna and easily desolder it, replacing it with a wired connection to a spare 2.4 GHz external antenna. That’s all it took to boost the headset’s range from barely one room to easily three rooms, which is a success by any measure.

Sadly, the USB transmitter dongle doesn’t have any intention of being opened and puts up a fight, so the process was a bit destructive. No problem, [rafii6312] simply fired up Fusion360 to design a new 3D-printed enclosure that accommodated the new antenna. Pictures, instructions, and 3D model files are all available on the project page, if you want to improve your headset, too.

This kind of antenna upgrade is reasonably straightforward, but if one is armed with the right knowledge, antenna upgrades from scratch using scrap wire and dollar store hardware are entirely possible. Just be sure to pick an antenna that doesn’t weigh down your headset.