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Chanukah Display 2019 Two displays total over 4,500 NeoPixel LEDs.  (Built to survive 60 MPH winds).   Each display is controlled by a Teensy 3.2 paired with an OCTO Shield. Minorah Car Parade in LA  Razzler: POV LED Top 2018     Uses STM32 processor and MPU-6050 to get Angular Velocity  Wood Milling required, NO? Design Files. https://nathanpetersen.com/2018/05/15/razzler-pov-led-top/ https://www.hackster.io/nathanpetersenn/razzler-pov-led-toy-top-4fee5c Onstar like service for Cyclists  Using a (mainly) European sigfox.com data messaging cloud service, whose coverage map serves major U.S. cities and the ocean off the coast of L.A. extending past Catalina.  Typical; service fee for 50 (12-bytes) messages a day: $22 a year. The Arduino MKR board for this service is currently sold in Europe only. More Example Projects  Those other IO pins on 32 Bit Processors I2S   Fa...

 New "World's fastest compact microcomputer" The Teensy 4.0   $19.95              ARM Cortex-M7 processor at 600 MHz, contained in NXP iMXRT1062 chip Executes 2 instructions at a time (about 40% to 50% of the time compiled by TeesyDuino),   Employing tightly coupled split memory with 2 64 bit paths.. FPU handles Double Integers as well as Floats 1024K RAM (512K is tightly coupled)  2048K Flash (64K reserved for recovery & EEPROM emulation)  Lots of interfaces  6.6 X faster than ESP32 in one benchmark. (331 X faster than Arduino AVR Mega)  The Teensy board line appears to be the product of a one man operation run by Paul Stoffregen, he seems quite competent and is active on the support forum, his store is a little behind, it took some hinting to find the sales page for the Teensy 4.0.  It works with Arduino IDE his variation called TeesyDuino, using an installer t...

ongoing topic... Hand Gesture Input with Tactile Feedback There are circumstances and users that require unconventional input devices, some examples:   Leapmotion ,  the hand gesture input device maker and Ultrahaptics , the leading supplier of ultrasonic Haptic (tactile feedback) device have joined forces to form ultraleap.com a promotion site site for the combining of these 2 separate products to provide an enhanced user experience.    The Ultrasonic emitter array used in Haptic interfaces is similar to the Sound Flashlight recently demonstrated.  Some demonstrations allow a user to "feel" simple geometric shapes.    Leapmotion uses Stereo cameras and IR lights to identify hand gestures, it's a processing intensive and limited approach compared to scattered laser emitter 3D imaging using in Kinnect games and iPhone Face recognition, I lost some enthusiasm about Leapmotion when they retooled their software for use with VR headsets inste...

LEDs being current, rather than voltage operated devices require special driver circuits for optimal performance.  While simple applications like an indicator light that might be run at a fraction of it's rated capability, a series current limiting resistor is sufficient.  High power application running at the edge of the LED's max current rating require active regulation to compensate for the negative temperature coefficients of the LED, (measurement techniques are discussed in this university lab paper .) Low power LEDs can be driven with simple series resistor current control when powered from a regulated power supply. The LED Load Line graph be low helps one select a standard resistor value to get the ballpark current setting with a 5 volt power source.  Find where your LED's color line intersects the desired current, then pick the closest resistance line below that intersection. (This graph is from LEDnique.com , a collection of basic articles on LEDs aime...

 One of the technical leaders in so called 3D Holoographic LED Fans is Dseelab, in Sep 2019 they announced at an event the development of real time HDMI Video Input, it may be quite a while befiue it reaches the market.  Achieving this has been my holy grail, looking into FPGA based video processors and examining cartesian to polar code may no longer be necessary... Here's an interesting demo recently posted: Dseelab a leader in the "3D Holographic LED Fan" industry, has master-slave connections on their units, allowing them to be syncronized in an array, they also offer a programming API connecting though WiFi or with a wired serial connection to a PC.  The API supports remote update from the cloud and random play of 256 different media assets. The only other Holographic Fan maker offering a programming API and arrays for large image display is HYPERVSN of  Ireland.  The newest addition to the DseeLab line is their: 6 Blade 78cm, 960*960 res, ...

3D Hall Effect Sensors   The 3mm long TLE493D I2C interface 3D Hall Effect Sensor $1.97  The Infineon TLE493D is a bit of a cost breakthrough at under $2. Using 3 Hall Effect sensors in a single package, this chip can identify the position of a near magnetic field, that can for example make a longer lifespan replacement for precision continuous rotation potentiometers, that I used to see in aerospace surplus.  There is an Arduino support library available for the I2C interface devices (be sure you know the version your working with ), there are 4 different part numbers for the TLE493D-W2B6 fast wake-up chip, whose only difference is their I2C address, allows 4 of the 6 pin sensors to be used on a single bus.  • 3D magnetic flux density sensing of ±160 mT   (1 miliTeslas = 10 gauss).  • Programmable flux resolution down to 65 μT (typ.)   (Earth is 35-70  μT).  • X-Y angular measurement mode.  • 12-bit data resolution. ...

Make your Arduino dance to a little tune (or just pass on the message)  Someone with a Samsung washing machine wanted to be able to receive the "all done" notification from the other end of their house.  Here's a video sample with some owners interacting with their washes.   I didn't turn up a straightforward solution that I could easily implement (it's a lot easier to get music converted to drive a MIDI keyboard) there is plenty of reference material that should lea someone else to a solution .  Considering the usage time saving to code development time, it might be most practical to just put a wireless baby monitor near the washer. After glancing though some example projects and academic papers, I concluded that my solution would simply use a tempo-measuring-like setup measuring the interval between notes, if the sound impulses matched the tempo of the song I would call it a match (on review, the notes are not as staccato and easy to separate as a mu...

     I just ran across the Odroid Computer family, by a company in business for some years. Made by hardkernel.com ((South Korea) Their Raspberrry Pi-like boards run Linux and Arduino . (fun to have a Gigahertz speed Arduino , hopefully in Arduino mode, real time code execution is predictable) Their newest model the ODROID-XU4 has an ARM® big.LITTLE Octa core processor. It runs Ubuntu 16.04 and Android 4.4 KitKat, 5.0 Lollipop and 7.1 Nougat.  (You can make a multi-system boot setup.)  Benchmarks show the processor to be 7+ X faster than a Rasberry Pi 3.  Due to the 2 Ghz.  Cortex-A15 cores on the $49 board.  ( 2 - Big 2 Ghz cores,  2 - little 1.4 Ghz cores) While the Ras Pi System on Chip components are made by Broadcom (Irvine) the Odroid chip is made by Samsung (South Korea)  Their Raspberry Pi like boards have a 40 pin GPO connector with Power, Ground and some signals matching the Pi's. See their Wiki p...