Scratch Your Itch To Program A Microcontroller

February 3, 2023 by Al Williams 19 Comments

One of the fun things about “old school” computers is that it was fairly easy to get kids into programming them. The old Basic interpreters were pretty forgiving, and you could do some clever things easily with very little theory or setup. These days, you are more likely to sneak kids into programming via Scratch — a system for setting up programs via blocks in a GUI. Again, you can get simple results simply. With Scratch or Basic, complex things have a way of turning out complex, but that’s to be expected. If you want to try a Scratch-inspired take on microcontroller programming, check out MicroBlocks. It will work with several common boards, including the micro:bit and the Raspberry Pi Pico. You can use it in a browser or download versions for Linux, Windows, Mac, or even Chromebooks.

You can see a video below about the micro:bit version from a year ago. The tool is advancing, so you’ll find many new features compared to the video, but it will still give you an idea of what’s happening.

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Audio Playback Toy For DSP Adventures

February 2, 2023 by Bryan Cockfield 1 Comment

The declining costs of single-board computers has made serious computing power available for even the most trivial of tasks. It’s easy enough to slap a Raspberry Pi onto almost anything for nearly the same cost as a powerful 32-bit microcontroller platform, but this takes some of the fun out of projects for a few of us. Looking to get into the weeds can be a challenge as well, as [Michal Zalewski] demonstrates in this audio playback device he built from a simple 8-bit microcontroller.

The small toy takes audio input from a microphone through an op-amp and feeds this signal to an ADC within the AVR128DA28 microcontroller. The data is then stored on a separate memory chip ready to be played back through another op-amp paired with a speaker. This is where being familiar with the inner workings of the microcontroller comes in handy. By manipulating the interrupt routines in specific ways, the audio stored in memory can be played back at various speeds.

[Michal] intended this build to be a toy for one of his younger relatives, and for the price of a few ICs and buttons it does a pretty good job of turning a regular voice into a chipmunk voice like some commercial children’s toys some of us might remember. If the design aesthetics of this gadget look familiar, you may be thinking of his minimalist gaming device which we recently featured.

Cheap Kitchen Scale Learns To Speak JSON With ESP32

February 2, 2023 by Jenny List 5 Comments

Smart kitchen appliances are expensive, and more often than not, your usage data goes to whichever company operates the inevitable cloud service. Meanwhile the cheap ones contain substantially the same components without the smarts, so surely a hardware hacker can add a microcontroller to a cheap appliance for a bit of smart home technology without the privacy issues? It’s something [Liore] has done with an Amazon Basics kitchen scale, removing the electronics and wiring up an ESP32 to the load cell instead.

The Wheatstone bridge load cell circuit generates a tiny voltage difference that’s far too small for an ESP32 to measure, so in between the pair is an Avia Semiconductor HX711 strain gauge amplifier module. In addition, there’s a small OLED screen and the two buttons used in the Amazon scale are wired in too, providing the the kitchen scale functionality you’d expect.

Naturally the ESP32 brings along with it WiFi networking capabilities, which [Liore] has taken full advantage of here. By navigating a web browser to its IP address, you’ll receive the scale’s current reading in JSON format. This should make it easy to integrate with other systems, from Home Assistant to OctoPrint. We can see that there is plenty of scope for further enhancements for those prepared to write a little code.

Of course, this isn’t the first enhanced scale we’ve brought you, here’s one with Bluetooth. We’ve also seen hackers dispense with the kitchen-safe trappings and build the load cell directly into their own contraptions.

A wooden box sits on a darker wooden table. The box has a red, glowing number 8 on it.

Ambient Display Tells You If Borealis Is Coming To Town

January 29, 2023 by Navarre Bartz 8 Comments

For those times when you’d rather not get sucked down another internet rabbit hole when you really just wanted the weather, an ambient display can be great. [AlexanderK106] built a simple ambient display to know the probability the Northern Lights would visit his town.

Starting with a NodeMCU featuring the ESP8266, [AlexanderK106] walks us through a beginner-friendly tutorial on how to do everything from configure the Arduino IDE, the basics of using a breadboard. finding a data source and parsing it, and finally sticking everything into an enclosure.

The 7-segment display is taped and set into the back of the 1/4″ pine with enough brightness to shine through the additional layer of veneer on top. The display is set to show one digit and then the next before a three second repeat. A second display would probably make this easier to use day-to-day, but we appreciate him keeping it simple for this tutorial.

Looking for more ambient displays? Checkout the Tempescope or this clock that lets you feel the temperature outside!

3D Printed Triptych Shows Trio Of AI-Generated Images

January 20, 2023 by Tom Nardi 11 Comments

Fascinated by art generated by deep learning systems such as DALL-E and Stable Diffusion? Then perhaps a wall installation like this phenomenal e-paper Triptych created by [Zach Archer] is in your future.

The three interlocking frames were printed out of “Walnut Wood” HTPLA from ProtoPasta, and hold a pair of 5.79 inch red/black/white displays along with a single 7.3 inch red/yellow/black/white panel from Waveshare. There are e-paper panels out there with more colors available if you wanted to go that route, but judging by the striking images [Zach] has posted, the relatively limited color palettes available on these displays doesn’t seem to be a hindrance.

Note the clever S-shaped brackets holding in the displays.

To create the images themselves, [Zach] wrote a script that would generate endless customized portraits using Stable Diffusion v1.4, and then manually selected the best to get copied over to a 32 GB micro SD card. The side images were generated on the dreamstudio.ai website, and also dumped on the card.

Every 12 hours a TinyPico ESP32 development board in the frame picks some images from the card, applies the necessary dithering and color adjustments to make them look good on the e-paper, and then updates the displays. Continue reading “3D Printed Triptych Shows Trio Of AI-Generated Images” →

RP2040 DMA Hack Makes Another ‘CPU Core’

January 20, 2023 by Dave Rowntree 16 Comments

[Bruce Land] of Cornell University will be a familiar name to many Hackaday readers, searching the site for ‘ECE4760′ will bring up many interesting topics around embedded programming. Every year [Bruce] releases yet more of the students’ work out into the wild to our great delight. This RP2040-based project is a bit more abstract than some previous work and shows yet another implementation of an older hack to utilise the DMA hardware of the RP2040 as another CPU core. While the primary focus of the RP2040 DMA subsystem is moving data between memory spaces, with minimal CPU intervention, the DMA control blocks have some fairly complex behaviour. This allows for a Turing-complete CPU to be implemented purely with the DMA hardware and a sprinkling of memory.

The method ties up three of the twelve DMA channels, and is estimated to have a similar performance to ‘an Arduino’ but [Bruce] doesn’t specify which one of the varied models that could be. But who cares anyway? Programming the CPU is a matter of leveraging the behaviour of the hardware, which is all memory mapped and targetable by the DMA. For example, the CPU can waggle GPIO pins by using the DMA to write values to the peripheral address space. The basic flow can be seen in the image above. DMA0 is used as the program counter, which points DMA1 to an array of DMA control blocks, a sequence of which codes for some of the ‘opcodes’ of the CPU model. DMA0 chains to (hands over control to) DMA1 which reads the control blocks and configures itself accordingly. DMA1 performs whatever data move is programmed, chains to DMA2, which in turn reprograms the DMA0 program counter to point to the next block in the list to be executed by DMA1.

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A small electronic board next to colorful stylized speaker

Soundscape Sculpture Is Pleasing Art For Your Ears

January 18, 2023 by Chris Wilkinson 4 Comments

Artist and self-described “maker of objects” [Daric Gill] is sharing some of the world’s most pleasing and acoustically interesting soundscapes with museum patrons in his latest work, ‘The Memory Machine: Sound‘.

Now featured at the Center of Science and Industry museum, the interactive stereo soundscape generator resembles three decorated ‘tree trunks’, suspended high above the exhibition floor. When visitors approach the artwork, they are treated to a randomly selected soundscape sample.

The build, which is described in blog form here, teases just some of the sixty soundscape samples that can be heard. These include the noisy chattering of crowds underneath the Eiffel Tower in Paris, the mellow melodies of a meadow high in the Swiss Alps, and the pumping atmosphere of a baseball match played in Yankee Stadium, New York City.

Only the middle trunk reveals the electronic soul of the installation – an Adafruit M4 Feather Express, Music Maker Featherwing and a motion sensor. The flanking trunks house the speakers and amplifier. The motion sensor triggers the microcontroller, which then plays a randomly selected sample from an SD card.

[Daric] went to great lengths to reuse discarded materials, and even cannibalized parts from other sculptures to see his vision through. This focus underpins a substantial amount of woodworking and machining that went into this build, so the full video is certainly worth a watch to see the whole project come together.

Make sure to check out our coverage of other funky installations, like this mesmerizing ceiling decoration.

Continue reading “Soundscape Sculpture Is Pleasing Art For Your Ears” →