Getting Started With The TPS22917 Load Switch

From Seth Kerr of Oak Dev Tech:

Getting Started With The TPS22917 Load Switch

Trying to figure out how to reduce the power consumption of your project with multiple peripherals can be tricky, especially if these peripherals are operating off different power supplies than your main controller. This is where the easy to use TPS22917 Power Switch/Load Driver from Texas Instruments comes in.Packed into a tiny SOT23 package, the TPS22917 is compact enough to fit into any project, requiring just four total components including the main IC. Combined together on a small breakout board, we then have an easy to use form factor that can be used to easily integrate it right into your project without the extra hassle.

In this tutorial we’re going to show you how easily it is to use our TPS22917 breakout board in your project.

Getting Started With The TPS22917 Load Switch

Jared Wolff talks Cellular IoT

The Amp Hour #509: Cellular IoT with Jared Wolff

Welcome Jared Wolff of Circuit Dojo!

Jared is a graduate of the Rochester Institute of Technology (which Chris also considered attending). He did co-ops while there, like we talked about on last week’s episode.

While on co-op at Cisco, he was in the cable group and marveled at the techs doing repairs with magnet wire.

He is an east coast guy at heart, so he moved back to Connecticut eventually

Jared worked at Apple for a while, but the lifestyle is difficult because of time requirements and stressful travel. He was also there when Steve Jobs was still around and there was a bit of over the top hero worship.

Nordic’s early bluetooth chipset was the nRF8001, which was a transceiver over SPI (no micro)

Working for startups was interesting if you thrive on doing a lot of different things

Jared Wolff talks Cellular IoT

Hackaday is hiring writers

You wake up in the morning, and check Hackaday over breakfast. Then it’s off to work or school, where you’ve already had to explain the Jolly Wrencher to your shoulder-surfing colleagues. And then to a hackspace or back to your home lab, stopping by the skull-and-cross-wrenches while commuting, naturally. You don’t bleed red, but rather #F3BF10. It’s time we talked.

The Hackaday writing crew goes to great lengths to cover all that is interesting to engineers and enthusiasts. We find ourselves stretched a bit thin and it’s time to ask for help. Want to lend a hand while making some extra dough to plow back into your projects? We’re looking for contributors to write a few articles per week and keep the Hackaday flame burning.

Contributors are hired as private contractors and paid for each article. You should have the technical expertise to understand the projects you write about, and a passion for the wide range of topics we feature. You’ll have access to the Hackaday Tips Line, and we count on your judgement to help us find the juicy nuggets that you’d want to share with your hacker friends.

If you’re interested, please email our jobs line (jobs at hackaday dot com) and include:

  • One example article written in the voice of Hackaday. Include a banner image, at least 150 words, the link to the project, and any in-links to related and relevant Hackaday features. We need to know that you can write.
  • Details about your background (education, employment, interests) that make you a valuable addition to the team. What do you like, and what do you do?
  • Links to your blog/project posts/etc. that have been published on the Internet, if any.

Read more….

Hackaday is hiring writers

The State of OSHdata and Open Hardware

There’s a lot happening, so I want to take some time to update you on the OSHdata project and what we see happening next in the broader Open Source Hardware community as we look ahead to Open Hardware Month in October.

OSHdata was started earlier this year by myself (Harris Kenny) and my friend and co-creator Steven Abadie. We worked together to create and publish the 2020 Report on the State of Open Source Hardware, which we released under an open CC BY-SA 4.0 International license.

Our report took a deep dive into how to price open source products, which licenses are being used by open source hardware projects, the growth of open hardware, and potential ways that we would modify OSHWA’s certification application. In parallel, OSHWA has been working on developing an API to increase accessibility of their data—which means more and easier reporting in the future!

After publication, we co-authored articles on new open hardware for Make: magazine and received media coverage in a number of different places like from Gareth Halfacree, Fabbaloo from Sarah Goehrke, and the Makers on Tap podcast co-hosted by Aaron Peterson and Joe Spanier. In many ways, this project has already exceeded our expectations. But there’s still more work to be done.

Our research has been read in over 40 countries around the world, on every continent—except Antarctica. Our report helped increase awareness of the certification program and created a sense of friendly competition between some of the leading Open Source Hardware companies in the world. Since our report was first published, the program went from slightly over 400 certifications to now boasting over 1,000 certifications!

The State of OSHdata and Open Hardware

Artistic PCB Design for Terrified Beginners workshop

Hardwaer hacker kliment created a workshop for the recent HOPE conference:

From the Artistic PCB Design for Terrified Beginners workshop

If you’re not familiar with some of those concepts:

  • PCBs stands for Printed Circuit Boards, the things that electronic devices are build on
  • Art means people creating wonderful (or awful) things for other people to enjoy
  • terrified beginner is someone who we all either are or have been at some point

I’m Kliment, and I’m doing this workshop to achieve one or more of the following things:

  1. Get art people to play with electronics
  2. Get electronics people to play with art
  3. Give the two groups above a common language so they can talk to each other
  4. Get people to build something cute and have fun

We’re going to be making a [SAO].  A [SAO] is a small circuit board that gets attached as a decorative or functional addition to one of the many badges that are so popular at hacker events. We’re going to make one that doesn’t do much (except light up). Except it won’t be shitty! It will be pretty! So let’s call it a pretty addon!

Artistic PCB Design for Terrified Beginners workshop

LED powered by body heat

bobricius designed this low voltage step up converter module with white LED:

40mV module for body heat powered white LED


  • startup voltage 40mV
  • requires only peltier element (not included)
  • white LED


  • Peltier module generates very low electricity from temperature difference.
  • Has two sides. If you keep COOL side (with aluminium cooler) at about 20 degrees and HOT side you heat with your body (fingers, forehead) with temperature etc 37 degrees you get about 40mV.
  • This converter module increases this very low voltage to power white led.

Here is a video of the project:

LED powered by body heat

Rapid Charging Supercapacitors

From the Hackaday blog:

Rapid Charging Supercapacitors

Battery technology is the talk of the town right now, as it’s the main bottleneck holding up progress on many facets of renewable energy. There are other technologies available for energy storage, though, and while they might seem like drop-in replacements for batteries they can have some peculiar behaviors. Supercapacitors, for example, have a completely different set of requirements for charging compared to batteries, and behave in peculiar ways compared to batteries.

This project from [sciencedude1990] shows off some of the quirks of supercapacitors by showing one method of rapidly charging one. One of the most critical differences between batteries and supercapacitors is that supercapacitors’ charge state can be easily related to voltage, and they will discharge effectively all the way to zero volts without damage. This behavior has to be accounted for in the charging circuit. The charging circuit here uses an ATtiny13A and a MP18021 half-bridge gate driver to charge the capacitor, and also is programmed in a way that allows for three steps for charging the capacitor. This helps mitigate the its peculiar behavior compared to a battery, and also allows the 450 farad capacitor to charge from 0.7V to 2.8V in about three minutes.

If you haven’t used a supercapacitor like this in place of a lithium battery, it’s definitely worth trying out in some situations. Capacitors tolerate temperature extremes better than batteries, and provided you have good DC regulation can often provide power more reliably than batteries in some situations. You can also combine supercapacitors with batteries to get the benefits of both types of energy storage devices.

Rapid Charging Supercapacitors

UV-C Germicidal LED Module

From Jeremy S Cook on the Tindie blog:

UV-C Germicidal LED Module

With concerns about the transmission of COVID-19 at the forefront of society’s collective consciousness, UV light—especially the UV-C range—has been put forth as a possible solution. But how does one produce UV light indoors? UV LEDs of course!

For this purpose, prolific Tindarian Bobricius has come up with an LED module with a single 275nm UV-C light onboard. It includes the proper resistor to keep it functioning properly via a 9V power source, making it easy to implement.

While it may be effective, the listing notes that it is untested on viruses and bacteria. You’ll of course want to use it appropriately based on that information, and also note that it can be harmful to skin and eyes.

So why then did Bobricius make this contraption? As in so many works of science fiction, he had been dreaming of a radiation killing module. Now perhaps such a device can be used for good. Notably, there is a significant discount for orders of more than one, so perhaps a “killer array” would be a better option than a single source of radiation in this case!

Of course, makers aren’t just on the germ-offensive these days. As seen here, there’s been a huge push to produce PPE, especially during early shortages of a few months ago.

UV-C Germicidal LED Module

Finding RF Cable Impedance

From Al Williams on Hackaday:

Finding RF Cable Impedance

At DC and low frequency, we can pretend wires are perfect conductors. At radio frequencies, though, there are many effects that you need to take into account for wires and cables. One of these is characteristic impedance. If you have a marked cable, you can look it up on the Internet, of course. But what if you don’t know what kind of wire it is? With help from [The Offset Volt], you can measure it as he shows in the video below.

This is one of those things that used to take exotic test equipment like an LCR bridge, but these days meters that measure inductance and capacitance are commonplace. The trick is simple: measure the capacitance and then short one end of the cable and measure the inductance.

Once you have those numbers, it is easy to do a little math and determine the impedance. It doesn’t matter how long the cable is. The length will change the individual readings, but the ratio of the two readings will remain relatively constant.


Spotify and Pandora Wireless Display

From Glen Akins’ bikerglen blog:

Spotify and Pandora Wireless Remote Track / Artist / Album Display

I use Pandora and Spotify a lot–typically from 7 in the morning until 11 at night. I got frustrated with the Spotify and Pandora apps on my Pixel 2 and their inability to find and control my Chromecast Audio players reliably. I also wanted a quick way to identify new songs or artists I heard without having to find my phone and open an app.

To solve these problems, I moved my music playing ecosystem to Linux and installed a wired Dante digital audio network for audio distribution. Finally I built a retro 14-segment, scrolling, always-on LED display that I could quickly glance at to discover what song was playing without having to find my phone and open an app.

Spotify and Pandora Wireless Display