The Curved Nature Of Time Clock

While we’re told that space-time curves, we aren’t sure that was what [andrei.erdei] was going for when he built a great-looking curved LED clock. The LEDs are courtesy of a strip of 84 WS2812 smart LEDs, the curve comes from a 3D printed part, and a Wemos D1 mini provides the brains.

Like all of our favorite clocks, this one has a unique way of displaying the time. If you find the description in the post hard to understand, the video below makes it a bit easier to wrap your head around. Note the time appears in the top left corner of the video in several cases — so you can check to see if you’re reading it correctly.

The secret sauce, of course, is the curved plastic grid that holds the LEDs. Because of the unusual shape, supports are a must and there are notes in the post about the settings used to get the best results. With 84 LEDs, the software has to be careful not to turn them to full brightness at one time, or else the clock would need a 6 amp power supply. Instead, the software limits the brightness to a little less than half of the maximum. No LED is ever white, and not all LEDs are on at once. The clock works easily, according to [andrei], with a 2 A supply. The clock has a WiFi connection where you can set things up easily.

Overall, a nice-looking project that would look at home on a science fiction movie set. We’ve seen color clocks before. If you want to economize on LEDs, we’ve seen a clock with only five!

Continue reading “The Curved Nature Of Time Clock”

A montage of a "death stranding" lamp in two different color modes, purple on the left and blue on the right

Illuminate Your Benched Things With This Death Stranding Lamp

[Pinkman] creates a smart RGB table lamp based off of the “Odradek device” robot arm from the video game “Death Stranding”.

[Pinkman] adds a XIAO BLE nRF52840 Sense device, with Bluetooth support, microphone and TinyML capability. The nRF52840 is used to push data to the five WS2812 strips, one for each “blade” of the lamp, and also connects to a TTP223 capacitive touch controller to add touch input detection. The TinyML portion of the nRF52840 allows for custom keyword training to turn on the lamp with voice commands ([Pinkman] uses “Bling Bling”). [Pinkman] has also provided Bluetooth control, allowing the color and pattern to be changed from a phone application.

The lamp is 3D printed with the build being based off of [Nils Kal]’s Printables files. Each of the five blades has a white 3D-printed diffusor plate to help ease out the hot spots for the LED strip. The lamp is fully adjustable in addition to having cavities, channels and access points for “invisible” wiring. [Pinkman] has also upgraded the original 3D files to allow for the three wires needed to drive the WS2812, instead of the two wires that [Nils] had allotted in the original.

[Pinkman] has all of the code, STL files and training data available for download, so be sure to check it out. Lamps are a favorite of ours and we’ve featured our fair share, including 3D printed Shoji lamps and RGB wall lamps.

Video after the break!

Continue reading “Illuminate Your Benched Things With This Death Stranding Lamp”

Addressable LEDs From A Z80

If you buy WS2812s under the Adafruit NeoPixel brand, you’ll receive the advice that “An 8 MHz processor” is required to drive them. “Challenge Accepted!“, says [ShielaDixon], and proceeded to first drive a set from the 7.3 MHz Z80 in an RC2014 retrocomputer, and then repeat the feat from a 3.5 MHz Sinclair ZX Spectrum.

The demos in the videos below the break are all programmed in BASIC, but she quickly reveals that they call a Z80 assembler library which does all the heavy lifting. There’s no microcontroller behind the scenes, save for some glue logic for address decoding, the Z80 is doing all the work. They’re all implemented on a pair of RC2014 extension cards, a bus that has become something of a standard for this type of retrocomputer project.

So the ubiquitous LEDs can be addressed from some surprisingly low-powered silicon, showing that while it might be long in the tooth the Z80 can still do things alongside the new kids. For those of us who had the Sinclair machines back in the day it’s particularly pleasing to see boundaries still being pushed at, as for example in when a Z80 was (almost) persuaded to have a protected mode.

Continue reading “Addressable LEDs From A Z80”

"The Great Resistor" color code illumination project

The Great Resistor Embiggens The Smallest Value

With surface-mount components quickly becoming the norm, even for homebrew hardware, the resistor color-code can sometimes feel a bit old-hat. However, anybody who has ever tried to identify a random through-hole resistor from a pile of assorted values will know that it’s still a handy skill to have up your sleeve. With this in mind, [j] decided to super-size the color-code with “The Great Resistor”.

Resistor color code from Wikipedia with white background
How the resistor color-code bands work

At the heart of the project is an Arduino Nano clone and a potential divider that measures the resistance of the test resistor against a known fixed value. Using the 16-bit ADC, the range of measurable values is theoretically 0 Ω to 15 MΩ, but there are some remaining issues with electrical noise that currently limit the practical range to between 100 Ω and 2 MΩ.

[j] is measuring the supply voltage to help counteract the noise, but intends to move to an oversampling/averaging method to improve the results in the next iteration.

The measured value is shown on the OLED display at the front, and in resistor color-code on an enormous symbolic resistor lit by WS2812 RGB LEDs behind.

Inside view of the great resistor showing WS2812 LEDs and baffle plates
Inside The Great Resistor, the LEDs and baffle plates make the magic work

Precision aside, the project looks very impressive and we like the way the giant resistor has been constructed. It would look great at a science show or a demonstration. We’re sure that the noise issues can be ironed out, and we’d encourage any readers with experience in this area to offer [j] some tips in the comments below. There’s a video after the break of The Great Resistor being put through its paces!

If you want to know more about the history of the resistor color code bands, then we have you covered.  Alternatively, how about reading the color code directly with computer vision?

Continue reading “The Great Resistor Embiggens The Smallest Value”

Arduino hearing test device overview

DIY Arduino Hearing Test Device

Hearing loss is a common problem for many – especially those who may have attended too many loud concerts in their youth. [mircemk] had recently been for a hearing test, and noticed that the procedure was actually quite straightforward. Armed with this knowledge, he decided to build his own test system and document it for others to use.

audiogram showing the results of the arduino hearing test device
Resultant audiogram from the device showing each ear in a different color

By using an Arduino to produce tones of various stepped frequencies, and gradually increasing the volume until the test subject can detect the tone, it is possible to plot an audiogram of hearing threshold sensitivity.  Testing each ear individually allows a comparison between one side and the other.

[mircemk] has built a nice miniature cabinet that holds an 8×8 matrix of WS2812 addressable RGB LEDs.  A 128×64 pixel OLED display provides user instructions, and a rotary encoder with push-button serves as the user input.

Of course, this is not a calibrated professional piece of test equipment, and a lot will depend on the quality of the earpiece used.  However, as a way to check for gross hearing issues, and as an interesting experiment, it holds a lot of promise.

There is even an extension, including a Class D audio amplifier, that allows the use of bone-conduction earpieces to help narrow down the cause of hearing loss further.

There’s some more information on bone conduction here, and we’ve covered an intriguing optical stimulation cochlear implant, too.

Continue reading “DIY Arduino Hearing Test Device”

A 3d printed ghost next to the base of an LED tea light that has 4 LEDs poking out and the IR receiver port and micro-USB connector showing.

A Cold Light To Warm Your Heart

Halloween is coming fast and what better way to add to your Halloween ornamentation than [Wagiminator]’s cute NeoCandle tea light simulator.

[Wagiminator] has modified a 3D printed ghost along with extending [Mark Sherman]’s light simulation code to create a cute light that’s perfect for the holiday season. The NeoCandle uses an ATtiny85 chip to power four WS2812 NeoPixel jelly bean LEDs. The device has an infrared (IR) receiver to be able to control it from a remote that speaks the NEC protocol. There is a light sensor that allows the unit to dim when it detects ambient light and the whole unit is powered off of a micro-USB connection.

The ATtiny85 have limited program flash and [Wagiminator] packs in a lot of functionality in such a small package, squeezing in a bit-banging NeoPixel driver in only 18 bytes of flash that can push out a transfer rate 762 kpbs to update the LEDs. The pseudo-random number uses a Galois linear feedback shift register and comes in at 86 bytes of flash, with the IR receiver implementation code being the largest using 234 bytes of flash. The ATtiny85 itself has 8 KB of flash memory so maybe it’s possible to push [Waginminator]’s code to even more restrictive Atmel devices in the ATtiny family.

With microcontrollers and LEDs becoming so cheap and ubiquitous, making realistic flames with them is becoming accessible, as we’ve seen with previous projects on electronic candles.

Continue reading “A Cold Light To Warm Your Heart”

three sensory bridge audio spectrum analyzers, one in use with a lit LED array plugged in, the other facing the camera and leaning against the third, all on a table

The Sensory Bridge Is Your Path To A Desktop Rave

[Lixie Labs] are no strangers to creating many projects with LEDs or other displays. Now they’ve created a low latency music visualizer, called the Sensory Bridge, that creates gorgeous light shows from music.

The Sensory Bridge has the ability to update up to 128 RGB LEDs at 60 fps. The unit has an on-board MEMS microphone that picks up ambient music to produce the light show. The chip is an ESP32-S2 that does Fast Fourier Transform trickery to allow for real-time updates to the RGB array. The LED terminal supports the common WS2812B LED pinouts (5 V, GND, DATA). The Sensory Bridge also has an “accessory port” that can be used for hardware extensions, such as a base for their LED “Mini Mast”, a long RGB array PCB strip.

The unit is powered by a 5 V 2 A USB-C connector. Different knobs on the device adjust the brightness, microphone sensitivity and reactivity of the LED strip. One of the nicer features is its “noise calibration” that can record ambient sound and subtract off the background noise frequency components to give a cleaner music signal. The Sensory Bridge is still new and it looks like some of the features are yet to come, like WiFi communication, accessory port upgrades and 3.5 mm audio input to bypass the on-board microphone.

The stated goals of the Sensory Bridge are to provide an open, powerful and flexible platform. This can be seen with their commitment to releasing the project as open source hardware, providing firmware, PCB design files and even the case STLs under a libre/free license. Audio spectrum analyzers are a favorite of ours and we’ve seen many different iterations ranging from ones using Raspberry Pis to others use ESP32s.

Video after the break!

Continue reading “The Sensory Bridge Is Your Path To A Desktop Rave”