Erich Styger has been working on a UPS with the Raspberry Pi to cover a short power out: There are different ways to ruin a Linux system. For the Raspberry Pi which uses a micro SD card as the storage device by default, it comes with two challenges: 1.Excessive writes to the SD card can […]
Author Archives: DP
Minimal ATSAMD21 computer
Johnson Davies shared detailed instructions of how to build an ATSAMD21-based computer on a prototyping board using a 32-pin ATSAMD21E: If you’re looking for something more powerful than the ATmega328 in the Arduino Uno a good choice is the ATSAMD21. This is an ARM Cortex M0+ processor with up to 256KB flash memory, 32KB RAM, […]
#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 […]
Arduino interface for TFA9842AJ power amplifier
Dilshan Jayakody writes, “I tested a couple of TFA9842AJ based amplifiers in the last couple of years. The main reason I liked TFA9842AJ is its simple, clean design, wide operating voltage, and high-quality bass-rich audio output. Thanks to it’s built-in DC volume control circuit this audio amplifier can easily interface with MCU. In this article, […]
App note: 3V DACs used in ±10V applications
Boosting DAC’s output to drive larger voltage tackled in this app note from MAXIM Integrated. Link here (PDF) Many modern systems have the majority of their electronics powered by 3.3V or lower, but must drive external loads with ±10V, a range that is still very common in industrial applications. There are digital to analog converters […]
App note: Tire pressure monitor system
NXP Semiconductor’s implementation of Tire pressure monitor (TPM) system. Link here (PDF) The Tire Pressure Monitoring System Reference Design consists of five modules: four tire modules and a receiver module. The tire modules consist of the MPXY80xx, the RF2, a battery, several discrete components, and a printed antenna. The receiver module has the MC33954, the […]
Semiconductor radioactivity detector: part 3
Robert Gawron has made a new version of his radioactivity detector project and wrote a post on his blog detailing its assembly: In this post I will present a new hardware version of my sensor, older versions are described in part I and part II. In comparison to the previous one, sensitivity is roughly x10 […]
The Nixie tube filadometer – a Nixie tube filament meter for your 3D printer
Dr. Scott M. Baker made a Nixie tube filament meter for his 3D Printer: First, I decided to upgrade from the Raspberry Pi Model B to a more recent Raspberry Pi Zero W that I had on hand. Wired Ethernet is so ~ 2013 after all, and wireless would be a lot more convenient. Next, […]
Open Trickler: The DIY smart powder trickler
Eric Higgins has a nice build log on his Open Trickler project a bluetooth-enabled smart powder trickler from off-the-shelf parts for under $60: Fundamentally, this is not a hard problem to solve. Read the value from the scale, run a motor that moves powder into the scale, turn off the motor when the scale reads […]
#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 […]
Teardown of a LogiMetrics A300/S traveling wave tube amplifier
LogiMetrics A300/S TWTA teardown by Kerry Wong: I just picked up a LogiMetrics A300/S 2 GHz to 4 GHz (S band) traveling wave tube amplifier (TWTA) on eBay. I had done an extreme teardown of an HP 493A TWTA a while ago and it was quite fascinating to see what’s inside of a TWT. This LogiMetrics […]
16 x 2 LCD controlled via power line
Vinod blogged about a 16×2 LCD with data over power line: Then I just thought why even 1 wire for data? Because we can easily multiplex the 1 wire data line with the Vcc line by keeping a diode + capacitor combination towards the LCD power supply pin. I am using an arduino board to do […]
App note: Crystal oscillator troubleshooting guide
App note from NXP Semiconductors dealing with oscillators in microcontrollers. Link here (PDF) Most microcontrollers can use a crystal oscillator as their clock source. Other options include external canned oscillators, resonators, RC oscillators, and internal clocks. The main advantages of a crystal oscillator are frequency accuracy, stability, and low power consumption. However, high reliability is […]
App note: Active cell balancing in battery packs
Cell balancing implementation from NXP Semiconductors. Link here (PDF) Batteries made of multiple cells connected in series are often used as a power source for common electronic devices. In multicell battery chains, small differences between the cells (due to production tolerances or operating conditions) tend to be magnified with each charge or discharge cycle. In […]
Aweigh: the open-source alternative to GPS
A team of student designers and engineers from the RCA and Imperial College have developed a substitute for GPS that does not rely on satellites, called Aweigh: Aweigh is an open navigation system that does not rely on satellites: it is inspired by the mapping of celestial bodies and the polarized vision of insects. Ancient seafarers and […]
#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 […]
Building a Jones Push-Pull Oscillator
Steve (VE7SL) has built a Jones Power-Oscillator using a pair of 6L6s and wrote a post on his blog detailing its assembly.
Homebrew DMX-controlled RGB LED light
Glen has written an article detailing his homebrew DMX-controlled RGB LED light: This project is a small DMX-512 controlled, color-changing RGB LED light. The light can be controlled via the DMX512 protocol or it can run a number of built-in programs depending on how the software is configured. The light incorporates an advanced 16-bit PIC24 microcontroller with […]
Arduino Shield for CAT M1 and NB-IoT modems
Michael Krumpus designed and built an Arduino shield for Nimbelink Skywire CAT M1 and NB-IoT modems, that is available on Github: Nimbelink has a development kit for use by product developers, but it’s rather expensive. I wanted to try out a Nimbelink CAT M1 modem without the dev kit, and since there are so many […]
App note: Reduced power dissipation of relay loads
Another app note from ON Semiconductors on using PWM technique to reduce power consumed when latching mechanical relays. Link here (PDF) Integrated circuit driver circuits often use relay loads in their application. Output drivers are a source of power dissipation on the IC. Latching relays can be used to keep sustaining load current at a […]