Alexander Weber has a nice build log on his drawbot called Mechpen, that is available on GitHub: This is Mechpen, my newest drawbot. The idea was to have a robot arm that could sketch on a rather large surface. It is a SCARA (Selective Compliance Assembly Robot Arm) robot arm, meaning the robot has a […]
Author Archives: DP
App note: MC13783 buck and boost inductor sizing
NXP’s app note on calculating inductor sizes using MC13783 PWM controller as example. Link here (PDF) The purpose of this application note is to provide a method of choosing the size of the inductors for the optimized switching regulators versus the current consumption of the application. This will allow to optimize the size and the […]
App note: Analog switch lowers relay power consumption
Clever way of starting-up relays discussed in this app note from Maxim Integrated. Link here Relays are often used as electrically controlled switches. Unlike transistors, their switch contacts are electrically isolated from the control input. On the other hand, the power dissipation in a relay coil may be unattractive for battery-operated applications. You can lower […]
USB Morse keyer
Dilshan Jayakody writes about a new open source project, the PIC16F886 based CW auto key controller with USB support: USB Morse Keyer is a microcontroller-based auto keyer project with following features: *USB / straight key / iambic key inputs *Support for both standalone and USB operating modes *64-character USB typeahead buffer and 6-character Morse key typeahead buffer […]
App note: Thermal mass flow sensors for gas and liquid applications
White paper from Integrated Device Technology on the emergence of MEMS thermal mass flow sensors. Link here (PDF) Flow meters represent the instrumentation of flow sensors and are used to measure the amount of flow that passes through them. There are in principal five different flow meter types: velocity flow, positive displacement flow, differential pressure […]
App note: Ferrite bead demystified
App note from Analog Devices hinting for proper selection of ferrite bead for you applications. Link here (PDF) An effective method for filtering high frequency power supply noise and cleanly sharing similar supply rails is the use of ferrite beads. A ferrite bead is a passive device that filters high frequency noise energy over a […]
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 […]
Building and Flashing ESP32 applications with Eclipse
Erich Styger shared the steps how to use Eclipse with CMake: The current Espressif documentation integrating with Eclipse are kind of broken and did not work for me (they are changing from make files to use CMake). The good news is that I have found a way to easily integrate the IDF with Eclipse which […]
The Script
Peter Scargill’s Script: Regular readers will know about the script that Aidan Ruff and I originally developed to put Node-Red and several other packages onto the Raspberry Pi for our own home control purposes. This has been developed with help from several people and in particular my friend Antonio “Mr Shark”. WELL – here is […]
tinyOSD & tinyFINITY – a tiny opensource video tx with full graphic OSD
tinyOSD and the tinyFINITY, a tiny open source video transmitter with integrated graphic OSD from fishpepper.de As I like fully integrated solutions I started to work on a new PCB design that includes a RTC6705 video transmitter and my tinyOSD into one tiny 16x16mm board called tinyFINITY. The image shows a preliminary version where I tested […]
The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers
Tim (cpldcpu) writes: Like many others, I was quite amazed to learn about a microcontroller sold for only 0.03 USD via the EEVblog last year. How was this possible? Many assumed this was a fire sale of an old product. Digging a bit further, it became apparent that there is an entire market segment of […]
Teardown and modification of an Electrophoresis power supply
Kerry Wong did a teardown of an EC600-90 electrophoresis high voltage power supply: Electrophoresis power supplies are commonly found in biology and other life sciences laboratories. These power supplies are usually capable of supplying high voltages and high currents required for gel electrophoresis–a method used for separating DNA, RNA and other protein fragments based on […]
App note: Silicon Labs’ TS3004 VS. the CMOS 555 – Determining lowest supply current for battery-powered applications
Good read on this app note from Silicon Labs comparing their low power but obsolete timer. Link here (PDF) The 555 timer is the workhorse of ICs, with close to a billion of them manufactured every year. Introduced in 1972, the 555 is still in widespread use because of its ease of use, reasonable price, […]
App note: Single-cell regulated Q-pump draws low quiescent current
Q-pump an alternative to inductor charge pump boost regulator for low power and sleepy microcontroller from Silicon Labs. Link here (PDF) In the switch-mode power supply world, capacitor-based charge pumps (or Q-pumps) generally aren’t useful for heavy lifting, but work well in niche micropower applications where space is at a premium. They work best in […]
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 […]
Sweeperino, Arduino based test instrument
Ashhar Farhan (VU2ESE) made an Arduino based sweeper for ham radio homebrewing, that is available on GitHub: The Sweeperino a very useful Arduino based test instrument. It is the following: *A very stable, low noise signal generator from 4 MHz to 160 MHz without any spurs *A high precision power meter with 90 db with […]
“Cigarette Pack”- 14MHz SSB QRP Micro-Transceiver
Peter Rachow (DK7IH) built a 14MHz SSB QRP Micro-transceiver into a cigarette packet size case: This article describes the “Cigarette Pack” SSB QRP transceiver” for 14MHz that I first had mentioned some months before. Recently, when taking it from the shelf, the transceiver dropped to the floor and was severely damaged. This lead to serious […]
Building a DIY 2.4 GHz Helical feed for the QO-100/Es’Hail-2 satellite
In this video Adam 9A4QV demonstrates his 2.4 GHz homemade helical feed for the QO-100/Es’Hail-2 satellite. Via RTL-SDR.
App note: Core independent voltage window signal detection using a single comparator
Presenting the usage of Core independent paripheral of PICs in this app note from Microchip. Link here (PDF) It is possible to find out whether a measured signal is below or above a certain value/reference using a single comparator. But, what if the desired interval is between two values, the undervoltage and overvoltage protection? The […]
App note: Power supply rejection ratio of low dropout voltage regulators
Here’s an app note about PSRR of LDO from Microchip. Link here (PDF) The Power Supply Rejection Ratio is the ability of a device, such as a Low Dropout Voltage regulator, to reject the various perturbations that can be found in its input supply rail by providing a greatly attenuated signal at the output. Generally, […]