Little RC Car Project Takes Inspiration From Mario Kart

October 18, 2024 by Lewin Day 9 Comments

RC cars used to be pretty simple. They’d go forwards, backwards, and steer if you got a full-function toy. However, with modern technology, it’s pretty trivial to make them more advanced. [Stuck at Prototype] demonstrates that nicely with his little Micro Racer Cars.

Each little RC car has its own ESP32 running the show, hooked up with a motor controller running a small DC gear motor at each wheel. Power is from a lithium-polymer battery on board the car, which is charged via USB C. 3D-printed components form the chassis and body of the vehicle. [Stuck at Prototype] set the cars up so they could be controlled via a smartphone app, or via a custom RC controller of his own design. He liked the latter solution after he realized how hard apps were to maintain. He also gave the cars a little color sensor so they could detect color patches on the ground, so they could change their behavior in turn. This was to create gameplay like Mario Kart, where hitting a color patch might make the car go fast, go slow, or spin out.

The video goes into great detail about everything these tiny tabletop racers can do. The racer cars were initially intended to be a Kickstarter funded project, but it never quite reached its goal. Instead, [Stuck at Prototype] decided to release the designs online instead, putting the relevant files on Github.

We’ve seen some other neat RC projects before, too. Video after the break.

Continue reading “Little RC Car Project Takes Inspiration From Mario Kart” →

Tiny LoRa GPS Node Relies On ESP32

October 17, 2024 by Lewin Day 10 Comments

Sometimes you need to create a satellite navigation tracking device that communicates via a low-power mesh network. [Powerfeatherdev] was in just that situation, and they whipped up a particularly compact solution to do the job.

As you might have guessed based on the name of its creator, this build is based around the ESP32-S3 PowerFeather board. The PowerFeather has the benefit of robust power management features, which makes it perfect for a power-sipping project that’s intended to run for a long time. It can even run on solar power and manage battery levels if so desired. The GPS and LoRa gear is all mounted on a secondary “wing” PCB that slots directly on to the PowerFeather like a Arduino shield or Raspberry Pi HAT. The whole assembly is barely larger than a AA battery.

It’s basically a super-small GPS tracker that transmits over LoRa, while being optimized for maximum run time on limited power from a small lithium-ion cell. If you’re needing to do some long-duration, low-power tracking task for a project, this might be right up your alley.

LoRa is a useful technology for radio communications, as we’ve been saying for some time. Meanwhile, if you’ve got your own nifty radio comms build, or anything in that general milleu, don’t hesitate to drop us a line!

Solve: An ESP32-Based Equation Solving Calculator

October 15, 2024 by Dave Rowntree 10 Comments

We’re suckers for good-looking old-school calculators, so this interesting numerical equation-solving calculator by [Peter Balch] caught our attention. Based around the ESP32-WROOM-32 module and an LCD, the build is quite straightforward from an electronics point of view, with the main work being on the software side of things.

A custom keyboard was constructed on Veroboard using a handful of tactile switches arranged in a charlieplexing array to minimize the number of IO pins consumed. For the display, an off-the-shelf 240×320 ILI9341-based module hooked up by SPI was used. A single lithium cell was used for the power supply, connected to a USB

You don’t need much to make a usable keyboard.

charger module, but you could just as easily substitute a 3 x AA battery box. The case was designed in DesignSpark mechanical and 3D printed. It’s unclear what keyboard version they settled on; there are options for one with keycaps and one without. Regardless, a 3D-printed frame sits atop the keyboard circuit, with the graphics printed on photo paper and a protective coversheet on top. Continue reading “Solve: An ESP32-Based Equation Solving Calculator” →

Internet Connected TI-84 To Cut Your Academic Career Short

September 29, 2024 by Danie Conradie 22 Comments

In an educational project with ethically questionable applications, [ChromaLock] has converted the ubiquitous TI-84 calculator into the ultimate cheating device.

The foundation of this hack lies in the TI-84’s link protocol, which has been a mainstay in calculator mods for years. [ChromaLock] uses this interface to connect to a tiny WiFi-enabled XIAO ESP32-C3 module hidden in the calculator. It’s mounted on a custom PCB with a simple MOSFET-based level shifting circuit, and slots neatly into a space on the calculator rear cover. The connecting wires are soldered directly to the pads of the 2.5 mm jack, and to the battery connections for power.

But what does this mod do? It connects your calculator to the internet and gives you a launcher with several applets. These allow you to view images badly pixelated images on the TI-84’s screen, text-chat with an accomplice, install more apps or notes, or hit up ChatGPT for some potentially hallucinated answers. Inputting long sections of text on the calculator’s keypad is a time-consuming process, so [ChromaLock] teased a camera integration, which will probably make use of newer LLMs image input capabilities. The ESP32 doesn’t handle all the heavy lifting, and needs to connect to an external server for more complex interfaces.

To prevent pre-installed programs from being used for cheating on TI-84s, examiners will often wipe the memory or put it into test mode. This mod can circumvent both. Pre-installed programs are not required on the calculator to interface with the hardware module, and installing the launcher is done by sending two variables containing a password and download command to the ESP32 module. The response from the module will also automatically break the calculator out of test mode.

We cannot help but admire [ChromaLock]’s ingenuity and polished implementation, and hopefully our readers are more interested in technical details than academic self-sabotage. For those who need even more capability in their calculator, we’d suggest checking out the NumWorks. Continue reading “Internet Connected TI-84 To Cut Your Academic Career Short” →

An ESP32 Delivers Perfect Slot Car Control

September 28, 2024 by Jenny List 3 Comments

If your memory of slot cars as a childhood toy is of lightweight controllers with wire-wound rheostats inside, then you’re many years behind the state of the art when it comes to competitive slot car racing. In that world the full force of modern electronics has been brought to keeping the car on the road, and as an example here’s [Maker Fabio] with a cutting edge controller that has an ESP32 at its heart.

It’s obvious that a huge amount of attention has gone into both the physical design of the unit and its software, and the result speaks for itself. The trigger sits on a proper bearing, and the sensor is a Hall-effect device on the PCB. The firmware was written in the Arduino IDE, and through the trigger and a rotary encoder all of its options can be configured on a small OLED display. Individual settings can be configured for each car, and we’re treated to a full explanation of this in the video.

We are told that the files for both software and hardware will be released in due course, as this is still a work in progress for the moment. The video meanwhile provides ample demonstration, so we look forward to the release.

It’s a surprise to find relatively few projects from the slot car world on these pages, given the amount of potential there is in them for electronic improvement. Here’s one from a few years ago though.

Continue reading “An ESP32 Delivers Perfect Slot Car Control” →

Large Language Models On Small Computers

September 7, 2024 by Bryan Cockfield 6 Comments

As technology progresses, we generally expect processing capabilities to scale up. Every year, we get more processor power, faster speeds, greater memory, and lower cost. However, we can also use improvements in software to get things running on what might otherwise be considered inadequate hardware. Taking this to the extreme, while large language models (LLMs) like GPT are running out of data to train on and having difficulty scaling up, [DaveBben] is experimenting with scaling down instead, running an LLM on the smallest computer that could reasonably run one.

Of course, some concessions have to be made to get an LLM running on underpowered hardware. In this case, the computer of choice is an ESP32, so the dataset was reduced from the trillions of parameters of something like GPT-4 or even hundreds of billions for GPT-3 down to only 260,000. The dataset comes from the tinyllamas checkpoint, and llama.2c is the implementation that [DaveBben] chose for this setup, as it can be streamlined to run a bit better on something like the ESP32. The specific model is the ESP32-S3FH4R2, which was chosen for its large amount of RAM compared to other versions since even this small model needs a minimum of 1 MB to run. It also has two cores, which will both work as hard as possible under (relatively) heavy loads like these, and the clock speed of the CPU can be maxed out at around 240 MHz.

Admittedly, [DaveBben] is mostly doing this just to see if it can be done since even the most powerful of ESP32 processors won’t be able to do much useful work with a large language model. It does turn out to be possible, though, and somewhat impressive, considering the ESP32 has about as much processing capability as a 486 or maybe an early Pentium chip, to put things in perspective. If you’re willing to devote a few more resources to an LLM, though, you can self-host it and use it in much the same way as an online model such as ChatGPT.

A small handheld word game called Batch Craze, where one player tries to get another to guess the word on the screen.

2024 Tiny Games Contest: Batch Craze Is Portable Charades, Kind Of

September 3, 2024 by Kristina Panos No comments

So there’s this commercial electronic game out there called Catch Phrase, which, as the game’s own catch phrase explains, is the game that’s played one word at a time. See, a word comes up on the screen, and you have to get the other person or team to guess what it is using gestures and such before the timer goes off. There are a bunch of rules, like you can’t say a word that rhymes, give the first letter, or the number of syllables.

Well, [ahixson1230] and company got their hands on the After Dark NSFW version but found it lacking in the edginess department. So naturally, [ahixson1230] was inspired to build a better one, with a touch screen in lieu of buttons, and a way for players to suggest words to be added to the list. In this version, a player presses anywhere on the screen to start the game, and a random word or phrase comes up. They act it out, get the other person to guess, and then pass the unit over to continue the fun.

Batch Craze is based on the Cheap Yellow Display, aka the ESP32-2432S028R, and [ahixson1230] highly recommends [witnessmenow]’s excellent resource on the subject. As of this writing, [ahixson1230] is still trying to get the speaker to work, and welcomes any help. Can you assist?

There’s still time to enter the 2024 Tiny Games Contest! You have until Tuesday, September 10th, so head on over to Hackaday.IO and get started!