Saulius Lukse writes, “Almost any sensor yields more interesting results if mounted on a moving platform. It’s time to mount TOF LIDAR on two precision rotary stages arranged for pan and tilt operation. Rig provides real-time position data along with distance to an obstacle. Using simple math we can calculate position in Cartesian coordinate system. […]
Author Archives: DP
Pool playing robot
BVarv wrote an instructable detailing the build of his pool playing robot project with Arduino: I redesign the prototype with servos, belts and gears at the points of rotation to add programmable motion. While doing so, I stumble across an easy win. It turns out that the “parked under the table” orientations, and the “perpendicular to […]
Free PCB Sunday: Pick your PCB
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will […]
App note: Nonvolatile STANDBY/ON Switch
Power status recovery in this application note from Maxim Integrated. Link here (PDF) Using an electronically programmable voltage reference (DS4305) as a single-bit nonvolatile memory cell, this circuit remembers the state of a STANDBY/ON switch that changes state with no operator present.
App note: Single-pushbutton ON/OFF power control
With the help of an MAX6816 debouncer from Maxim Integrated to form a single push button power switch. Link here (PDF) This application note presents a single-pushbutton power-control circuit. The design consists of an ON/OFF control circuit comprised of a push button, debouncer, and flip-flop. This circuit toggles the power output voltage by controlling an […]
Free PCB coupon via Facebook to 2 random commenters
Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]
Modifying the Teensy 3.5 and 3.6 for ARM SWD debugging
Erich Styger @ mcuoneclipse.com writes: Looking for a small, inexpensive ($25-30) ARM development board (say 120-180 MHz ARM Cortex-M4 with FPU, 512kB-1MB of FLASH and 256 KByte of RAM? Then have a look at the Teensy 3.5 and Teensy 3.6 by PJRC/Paul Stoffregen The only problem? it is not possible to debug it :-(. At […]
DIY polarity Led tweezers
Jesus Echavarria shared detailed instructions of how to make a simple tweezers for checking led polarity: I usually assemble by hand all the boards I make. I use SMD components, especially in 0805 format for resistors, capacitors and leds. With the last ones, I always have the same problem: I need to check the polarity of […]
The microTS – Smallest synth in the world
MicroTS, a smallest synth in the world from DIY synthesizer: The micro-TS is a key fob sized DIY synthesizer (61x41mm) with actually useable knobs like an analog synthesizer. The ball pen is for size reference. It has a one octave touch keyboard, 6 knobs and a stereo headphone output. Running on a CR2032 button cell battery […]
Playing with a surplus E-ink module
Sjaak @ smdprutser.nl writes: When I was in China last year I sourced a couple of small E-ink displays (GDEH0124S01) through Taobao. They were simple ones with 8 14 segment characters. After some searching on the Chinese website from the manufacturer I found the datasheet. It was by all means not complete and a lot […]
Fun with 1.1GHz Potato chips
Afroman writes, “I built a ring oscillator using a 1.125GHz 74 series logic inverter IC from Potato Semiconductor. It was fun.” Via Afrotechmods.
HP 7044A X-Y recorder teardown, Lorenz Attractor
Kerry Wong did a teardown of a vintage HP 7044A x-y recorder and programmed an Arduino Due to draw the Lorenz Atrractor using this recorder: To test the recorder, I wrote a simple program using Arduino Due that generates a Lorenz attractor. The min/max boundaries for each axis were obtained prior and they are used […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Reverse engineering the 76477 “Space Invaders” sound effect chip from die photos
Ken Shirriff has written an article on reverse engineering the 76477 “Space Invaders” sound effect chip: Remember the old video game Space Invaders? Some of its sound effects were provided by a chip called the 76477 Complex Sound Generation chip. While the sound effects1 produced by this 1978 chip seem primitive today, it was used […]
Calibrating Thermistors on a 3.3v Arduino
Edward Mallon writes, “I’ve managed to get cheap thermistors calibrated to about to +/- 0.2C with 3.3v Arduinos. Instead of playing whack-a-mole with the various sources of error, I simply rolled them into some synthetic Steinheart-Hart constants, and I was able to get the therm’s output onto the reference line from a si7051. The cool […]
Precision pressure meter with the Bus Pirate
Scott Harden has a nice build log on his precision pressure meter project: I just completed building a device capable of measuring temperature to one hundredth of a degree Celsius and pressure to one ten-thousandth of a PSI! This project is centered around an ICstation MS5611 temperature sensor breakout board which was small enough to […]
App note: Automotive reverse battery protection diode
Super Barrier Rectifier™ (SBR) from Diodes Incorporated offers good power efficiency compared to normal PN junction diode and design simplicity compared to MOSFETs reverse protection. Link here (PDF) This application note compares the performance of Diodes Inc. Super Barrier Rectifier™ (SBR) as an automotive reverse battery protection diode with other solutions. An overview of the […]
App note: A closer look at LVDS technology
A general overview of Low Voltage Differential Signaling (LVDS) from Diodes incorporated. Link here (PDF) With the increase in demand for high throughputs, current technologies are becoming less efficient. Data transmission devices like RS-422, RS-485, SCSI and other devices are limited in data rate and power dissipation. With LVDS, data rate has increased tremendously to […]
Free PCB coupon via Facebook to 2 random commenters
Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]
Beacon Keyer
Lukas Fässler from Soldernerd published a project writeup showing how he built a PIC-based beacon keyer: This is likely the first ham radio related project that I document here on this blog But my very first PIC project was a beacon keyer that I made for my father, HB9BBD. That was in 2013. A beacon […]