A Straightforward AI Voice Assistant, On A Pi

February 20, 2024 by Jenny List 6 Comments

With AI being all the rage at the moment it’s been somewhat annoying that using a large language model (LLM) without significant amounts of computing power meant surrendering to an online service run by a large company. But as happens with every technological innovation the state of the art has moved on, now to such an extent that a computer as small as a Raspberry Pi can join the fun. [Nick Bild] has one running on a Pi 4, and he’s gone further than just a chatbot by making into a voice assistant.

The brains of the operation is a Tinyllama LLM, packaged as a llamafile, which is to say an executable that provides about as easy a one-step access to a local LLM as it’s currently possible to get. The whisper voice recognition sytem provides a text transcript of the input prompt, while the eSpeak speech synthesizer creates a voice output for the result. There’s a brief demo video we’ve placed below the break, which shows it working, albeit slowly.

Perhaps the most important part of this project is that it’s easy to install and he’s provided full instructions in a GitHub repository. We know that the quality and speed of these models on commodity single board computers will only increase with time, so we’d rate this as an important step towards really good and cheap local LLMs. It may however be a while before it can help you make breakfast.

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All-Sky Camera Checks For Aurora

February 16, 2024 by Bryan Cockfield 4 Comments

The aurora borealis (and its southern equivalent, the aurora australis) is a fleeting and somewhat rare phenomenon that produces vivid curtains of color in the sky at extreme latitudes. It’s a common tourist activity to travel to areas where the aurora is more prevalent in order to catch a glimpse of it. The best opportunities are in the winter though, and since most people don’t want to spend hours outside on a cold night night in high latitudes, an all-sky camera like this one from [Frank] can help notify its users when an aurora is happening.

Because of the extreme temperatures involved, this is a little more involved than simply pointing a camera at the sky and hoping for the best. The enclosure and all electronics need to be able to withstand -50°C and operate at at least -30. For the enclosure, [Frank] is going with PVC tubing with a clear dome glued into a top fits to the end of the pipe, providing a water-resistant enclosure. A Raspberry Pi with a wide-angle lens camera sits on a 3D printed carriage so it can easily slide inside. The electronics use power-over-ethernet (PoE) rather than a battery due to the temperature extremes, which conveniently provides networking capabilities for viewing the images.

This is only part one of this build — in part two [Frank] is planning to build a system which can use this camera assembly to detect the aurora automatically and send out notifications when it sees it. Watching the night sky from the comfort of a warm house or sauna isn’t the only reason for putting an all-sky camera to use, either. They can also be used to observe meteors as they fall and then triangulate the position of the meteorites on the ground.

Memory Box Shows Photos Based On Fingerprint

February 13, 2024 by Kristina Panos 2 Comments

With his young son’s birthday coming up in a few weeks, [Mike Buss] wanted to build him something fun that the boy could hold on to all his life. After doing some sketching, [Mike] arrived at the idea to make a memory box uses a fingerprint scanner to show different pictures based on the fingerprint.

[Mike] started by rendering the box in Blender and then cutting a sizable hole in the lid for the E-ink screen. That’s around the time the first problem came up — there were weird vertical lines in the display. Sure enough, that screen was broken. Then he added the SD card reader, but the SD card wouldn’t work, and was heating up besides. Finally, the fingerprint scanner was causing issues, but it turned out that the power supply was at fault.

After all of that, [Mike] switched from an ESP32 to a Raspi Zero W to simplify the whole process of finding a photo tagged with the person’s fingerprint. [Mike] added a Python script that listens for new memories over Wi-Fi. A memory in this case consists of a picture, a description, a list of people tagged in the picture, and some additional metadata.

One important lesson [Mike] learned was that of balancing planning vs. just taking action. If he had taken the time to consider the complexity of the tagged-photo retrieval system, he would have arrived at an SBC solution much sooner. Be sure to check out the build video after the break.

You can have all sorts of fun with fingerprint scanners, like this one that opens a secret bookcase door.

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Will There Be Any Pi Left For Us?

February 2, 2024 by Jenny List 72 Comments

Our world has been abuzz with the news that Raspberry Pi are to float on the London Stock Exchange. It seems an obvious move for a successful and ambitious company, and as they seem to be in transition from a maker of small computers into a maker of chips which happen to also go on their small computers, they will no doubt be using the float to generate the required investment to complete that process.

New Silicon Needs Lots Of Cash

An RP1 chip on a Raspberry Pi 5. — The most important product Raspberry Pi have ever made.

When a tech startup with immense goodwill grows in this way, there’s always a worry that it could mark the start of the decline. You might for instance be concerned that a floated Raspberry Pi could bring in financial whiz-kids who let the hobbyist products wither on the vine as they license the brand here and there and perform all sorts of financial trickery in search of shareholder value and not much else. Fortunately we don’t think that this will be the case, and Eben Upton has gone to great lengths to reassure the world that his diminutive computers are safe. That is however not to say that there might be pitfalls ahead from a hobbyist Pi customer perspective, so it’s worth examining what this could mean.

As we remarked last year, the move into silicon is probably the most important part of the Pi strategy for the 2020s. The RP2040 microcontroller was the right chip with the right inventory to do well from the pandemic shortages, and on the SBCs the RP1 all-in-one peripheral gives them independence from a CPU house such as Broadcom. It’s not a difficult prediction that they will proceed further into silicon, and it wouldn’t surprise us to see a future RP chip containing a fully-fledged SoC and GPU. Compared to their many competitors who rely on phone and tablet SoCs, this would give the Pi boards a crucial edge in terms of supply chain, and control over the software.

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Simon Says With An RP2040

January 30, 2024 by Chris Lott No comments

The team of [Michael] and [Chimdi] from Cornell’s Designing with Microcontrollers (ECE 4760) Fall 2023 session designed a version of Simon Says on an RP2040 which they call Pico Says. It uses UDP packets over WiFi to communicate between the players, and supports VGA graphics for output. Each player’s hardware consists of a Pico W module plus a control panel containing the four LEDs and buttons ( red, green, yellow, and blue ) plus send and reset buttons.

For purposes of this lab, the modules were build on a solderless breadboard and used perfboard for the control panels. They weren’t entirely happy with their choice of UDP because they experienced frequent datagram dropouts in the noisy environment of the microcontroller lab. They also planned to implement sound effects, but ran out of time after spending too much time on the WiFi implementation, and had to drop that feature. In the end, however, they wrapped up their project and demonstrated a working game. We can only speculate whether this bonus lesson in resource management was intended by [Dr. Hunter Adams] or not.

Two ECE 4760 course references are highlighted in the write-up that helped them jump-start the project: the UDP and VGA examples for the Pico. These are good links to put in your RP2020 toolbox for future projects, in addition to the ECE 4760 course home page itself. We’ve covered several of these projects recently, as well as the curriculum switch from the Microchip PIC32MX-based Microstick II to the RP2040 last Spring.

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The Pi Pico replacement board in question, assembled, held diagonally in some type of holder

ProPico For Your Pro Pico Needs

January 3, 2024 by Arya Voronova 6 Comments

Ever feel like the Pi Pico board could be doing way more given its footprint? Does it bother you that the RP2040’s ADC quality is even further decreased because of the noisy onboard switching regulator? Miffed about decisions like the MicroUSB socket, the 2MB flash, or lack of the reset button? [Dmytro] brings us an open-source Pi Pico design, sporting the same RP2040 and a fully compatible footprint, but adding a number of improvements to its surroundings.

There’s a good few additions, all of them hacker-friendly – [Dmytro] adds comfortably-spaced reset and boot buttons, a USB-C socket, a dedicated low-noise voltage reference for the ADC, one more LED, and an I2C EEPROM footprint socket that is compatible with FRAM chips. Everything worth preserving is preserved – the pinout stays the same, including the SWD connector, which now sports an extra RESET pin. The bottom side USB testpoints remain, with only the four testpoints changed for more useful signals. Last but not least, the switching regulator is replaced by the venerable 1117 – you lose the ability to power your Pico from two AAs, and the capacitor series resistor requirement isn’t great, but you can easily put one of the drop-in 1117 replacement regulators on there.

What’s great is that the design is fully open-source, with KiCad files available. Want to design your own Pi Pico footprint board, improve upon this one even further, or maybe make a more tailored one? Treat yourself to the GitHub repository! There’s also a pinout diagram and a KiCanvas schematic for all your tinkering needs. We’ve covered drop-in replacements for classic drawer-inhabiting parts like the Pi Zero, for the 7805 (twice!), the 6502 CPU, and even for the DE9 serial port connector. No matter the purpose, they’re always a joy to see.

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.

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