Monthly Archives: August 2022

Dahl Winters Named OSHWA Trailblazer Fellow

via Open Source Hardware Association

Dahl Winters is presently CEO and Co-Founder of TerraNexum Inc. Her company’s goal is to provide a platform for optimizing cleantech/clean energy investment opportunities to enable rapid, profitable GHG drawdown at global scale.

Previously, Dahl was CEO/CTO of DeepScience Ltd for 7 years, leading a R&D consulting business that also built systems for science and sustainability in partnership with major corporations and research organizations. Her work there mostly focused on carbon dioxide removal and direct air carbon capture systems, as well as the analytics for scaling up those systems. One of these projects was registered as open-source hardware with OSHWA with the help of the OpenAir Collective, an all-volunteer group focused on advancing direct air carbon capture. This project grew into the focus of OpenAir’s Cyan/Carbon Forming mission which has helped many throughout the world to improve their knowledge of technical climate solutions.

Dahl is currently on the last year of her Ph.D in Systems Engineering at Colorado State University, within the Simske Lab. Her research has focused on how improvements to the carbon storage capacity and compressive strength of biochar-concrete composites can be engineered and how such a system can be successfully scaled to meet global needs for carbon sequestration and construction. Through the help of OSHWA’s Trailblazer Fellowship, Dahl can now also apply model-based systems engineering strategies to test how related, open-source hardware systems might also be successfully scaled within academia.

Prior to her recent work in carbon removal, Dahl also served as a consulting Geospatial Big Data Architect at a Fortune 500 company. There, she designed and built processing pipelines at scale to facilitate big data solutions and new tools for land cover monitoring. Before that, Dahl was a Staff R&D Scientist at DigitalGlobe, now Maxar Technologies, where she specialized in geospatial big data analytics and designed cloud-based and on-premises systems for ingesting, processing, and analyzing large quantities of geospatial data. Prior to this, she was an Environmental Scientist for Research Triangle Institute (RTI International), where she provided technical support to the U.S. Environmental Protection Agency’s Climate Change Division (CCD) under the Greenhouse Gas Reporting Program (GHGRP).

In her free time, Dahl enjoys catching up on the latest scientific discoveries within physics and quantum computing, going on hikes near her home in Evergreen, Colorado, examining the local wildflowers and birds, and doing nature photography with her husband Loren Winters.

A Day for Oscilloscopes

via SparkFun: Commerce Blog

I was rummaging in the basement of SparkFun HQ and came across an ancient oscilloscope. With my interest piqued, I thought it’d be entertaining to dive into its history and see how this device has evolved into the modern-day oscilloscope. This measurement tool has been a tremendous asset in its contribution to SparkFun’s success, so let's take the time to understand its birth and evolution. Let’s get started…

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The first oscilloscope was invented by French physicist Andre Blondel, who presented the device to the public in 1893. This device was capable of registering values of electrical quantities like alternating current intensity. Information was recorded using an ink pendulum attached to a coil on a moving paper, similar to a seismograph used to measure the scale of an earthquake. Blondel’s invention comprised of several mechanical devices, which made the measurements relatively inaccurate and the bandwidth rather small, between 10-19kHz. Four years later, German Scientist and Nobel Prize winner, Karl Ferdinand Braun, demonstrated the first cathode-ray oscilloscope. His work with high-frequency alternating currents led to the creation of an electronic display oscilloscope containing a cathode-ray tube (CRT). For the first time, this device provided visible patterns which graphically represented an electrical current.

Similar to most measuring equipment, oscilloscope development began to accelerate globally after World War II. In 1946, a company named Tektronix soon became the world leader in the advancement of oscillography. In turn, the manufacturing of oscilloscopes picked up, later leading to the adoption of it as an essential measurement tool for the electronics industry.

Tektronix 453 Oscilloscope

The dusty, ancient, and abandoned device found in SparkFun’s basement is a Tektronix 453 portable dual-trace oscilloscope.

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This analog device was introduced in 1965, as the main market driver for IBM, who wanted a portable oscilloscope for computer engineers to work on mainframe computers. Tektronix engineers were challenged to restrain the device's size to fit under an airline seat for traveling employees.

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An important part of shrinking the size was the invention of the “gear-shift” sweep knob, which allowed control of both sweeps with a single knob. The user can analyze waveforms using a regular sweep and delayed sweep by unlocking and locking the knob. For non-electrical engineers, this allows for scrolling and zooming of various sections within the waveform only using only one knob.

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Another contribution to the portability of the device was the locking handle that acted as both a carrying handle and a means of positioning the unit at a convenient angle for use. This marks the first time that any oscilloscope had a lockable dual-functioning carry handle and the design was patented by Tektronix. The Tektronix 453 oscilloscope was an engineering marvel in its time. Here are some specs for those who would like to reminisce…

Characteristic Value
Bandwidth 52.5 MHz
Rise Time <14ns
Deflection 5 mV/Div to 10 V/Div
Time Base 0.1 µs/Div to 5 s/Div
Input Impedance 1 MΩ
Probes Two P6010 3.5 ft 10X
Power 100 W

Analog vs. Digital

Analog oscilloscopes, like the Tektronix 453, flooded the market and displayed their essence throughout the electronics industry. By 1985, a company named LeCroy came out with the first high-speed digital storage oscilloscope (DSO). The DSO uses a fast analog-to-digital converter and memory chip to record and display a digital waveform. This oscilloscope relies heavily on its effective use of the installed memory and trigger functions. Not enough memory, and the user will miss the events. Poor trigger functionality, and the user will not be able to find the events. The DSO is a beautiful balancing act.

Although, the DSO is beautiful to some, it does come at a price. Oscilloscopes are built for precision, which must undergo rigorous quality control and hands-on manufacturing. There are several things to consider when purchasing such a device, for example, its important to note input stage impedance, ADC linearity and accuracy, sampling rate, digitizing range etc.

SparkFun Dropship Partner

Keysight, a former division of Agilent Technologies, released an oscilloscope line for college students, small labs, and hobbyists. The frequencies and number of channels available make them capable of different things.

Digital Storage Oscilloscope - 50MHz (TBS1052C)

Digital Storage Oscilloscope - 50MHz (TBS1052C)

Benchtop Oscilloscope - 100 MHz, 4-Ch, with US Power Cord

Benchtop Oscilloscope - 100 MHz, 4-Ch, with US Power Cord

Benchtop Oscilloscope - 1 GHz, 2-Ch. with US Power Cord

Benchtop Oscilloscope - 1 GHz, 2-Ch. with US Power Cord


SparkFun is a proud dropship partner of the KeySight line. If you are in the oscilloscope market, take a look at the illustrations above as they might pique your interest. Our SparkFun product pages will provide great insight for assessing your needs!

Resources and Going Further

Those looking to learn more, take a look at our How to Use an Oscilloscope tutorial.

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App note: Integrated power supply solution for vehicle tracking system

via Dangerous Prototypes

This evaluation board from Analog Devices features reliable and uninterruptible power supply for vehicle tracking system. Link here (PDF)

A vehicle tracking system (VTS) is typically installed in cars and trucks. A VTS provides real-time information about the speed, location, and direction of the vehicle using technology, such as a global positioning system (GPS).
For a VTS to work reliably, it needs to have a robust dc-to-dc power supply. A power supply must be designed to protect the system from common automotive fault conditions like load dump, cold crank, reverse polarity, and other potential destructive transients described in the ISO 7637-2 and ISO 16750-2 standards.
In addition, in the absence of power coming from the vehicle, the system must be able to switch to the backup battery to ensure continuous operation. Ultimately, an automotive power supply must comply with automotive electromagnetic interference (EMI) standards, specifically CISPR 25.

App note: Using an accelerometer for inclination sensing

via Dangerous Prototypes

Application note from Analog Devices to calculate for inclination angle from a single, dual or triple-axis accelerometers. Link here (PDF)

One common method for determining the tilt or inclination of a system is to integrate the output of a gyroscope. Although this method is straightforward, error associated with null bias stability can quickly compound as the integration period is increased, causing an apparent rotation even when the device is stationary.
Inclination sensing uses the gravity vector and its projection on the axes of the accelerometer to determine the tilt angle. Because gravity is a dc acceleration, any forces that result in an additional dc acceleration corrupt the output signal and result in an incorrect calculation. Sources of dc acceleration include the period of time when a vehicle is accelerating at a constant rate and rotating devices that induce a centripetal acceleration on the accelerometer. In addition, rotating an accelerometer through gravity causes an apparent ac acceleration as the projection of gravity on the axes of interest changes.

Easy Listening

via SparkFun: Commerce Blog

Hello all and welcome back to another Friday Product Post here at SparkFun Electronics! It's the last full week of August and we are hard at work with a lot of new boards that will be releasing in the coming weeks and months. In lieu of that, we have a bit of a lighter Friday post for you, with only two component products. The first of which is a compact, Wide Frequency Range Speaker option for your next audio project. Following that, we have a spool of two-conductor Hook-up Wire that can easily be used on any workbench or project station. And that's it! With that, let's jump in and take a closer look at both of this week's new products!

Wide Frequency Range Speaker - 3in. (Polypropylene Cone)

Wide Frequency Range Speaker - 3in. (Polypropylene Cone)


This wide range speaker is an excellent choice for compact applications requiring high fidelity music, or high intelligibility voice/communications audio. A talc-filled, polypropylene cone with a rubber surround allows this driver to be used either indoors or outdoors.

Hook-up Wire 2-Conductor - Clear (22AWG-7x30, Stranded, 25ft)

Hook-up Wire 2-Conductor - Clear (22AWG-7x30, Stranded, 25ft)


This standard 22 AWG hook-up wire is great for general connections between projects (low or high current applications). When you only need two connections to something (like power, a button or an indicator LED), this keeps your wiring nice and organized. It is also commonly used as speaker wire to connect from your speaker amp to the speakers.

And that's it! Like we said, a pretty easy week, for sure. As always, we can't wait to see what you make. Shoot us a tweet @sparkfun, or let us know on Instagram, Facebook or LinkedIn. Please be safe out there, be kind to one another, and we'll see you next week with even more new products!

Never miss a new product!

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Repair cafés in computing education | Hello World #19

via Raspberry Pi

Many technology items are disposed of each year, either because they are broken, are no longer needed, or have been upgraded. Researchers from Germany have identified this as an opportunity to develop a scheme of work for Computing, while at the same time highlighting the importance of sustainability in hardware and software use. They hypothesised that by repairing defective devices, students would come to understand better how these devices work, and therefore meet some of the goals of their curriculum.

A smartphone with the back cover taken off so it can be repaired.

The research team visited three schools in Germany to deliver Computing lessons based around the concept of a repair café, where defective items are repaired or restored rather than thrown away. This idea was translated into a series of lessons about using and repairing smartphones. Learners first of all explored the materials used in smartphones and reflected on their personal use of these devices. They then spent time moving around three repair workstations, examining broken smartphones and looking at how they could be repaired or repurposed. Finally, learners reflected on their own ecological footprint and what they had learnt about digital hardware and software.

An educational repair café

In the classroom, repair workstations were set up for three different categories of activity: fixing cable breaks, fixing display breaks, and tinkering to upcycle devices. Each workstation had a mentor to support learners in investigating faults themselves by using the question prompt, “Why isn’t this feature or device working?” At the display breaks and cable breaks workstations, a mentor was on hand to provide guidance with further questions about the hardware and software used to make the smartphone work. On the other hand, the tinkering workstation offered a more open-ended approach, asking learners to think about how a smartphone could be upcycled to be used for a different purpose, such as a bicycle computer. It was interesting to note that students visited each of the three workstations equally.

Two girls solder physical computing components in a workshop.
Getting hands-on with hardware through physical computing activities can be very engaging for learners.

The feedback from the participants showed there had been a positive impact in prompting learners to think about the sustainability of their smartphone use. Working with items that were already broken also gave them confidence to explore how to repair the technology. This is a different type of experience from other Computing lessons, in which devices such as laptops or tablets are provided and are expected to be carefully looked after. The researchers also asked learners to complete a questionnaire two weeks after the lessons, and this showed that 10 of the 67 participants had gone on to repair another smartphone after taking part in the lessons.

Links to computing education

The project drew on a theory called duality reconstruction that has been developed by a researcher called Carsten Schulte. This theory argues that in computing education, it is equally important to teach learners about the function of a digital device as about the structure. For example, in the repair café lessons, learners discovered more about the role that smartphones play in society, as well as experimenting with broken smartphones to find out how they work. This brought a socio-technical perspective to the lessons that helped make the interaction between the technology and society more visible.

A young girl solders something at a worktop while a man looks over her shoulder.
It’s important to make sure young people know how to work safely with electronic and physical computing components.

Using this approach in the Computing classroom may seem counter-intuitive when compared to the approach of splitting the curriculum into topics and teaching each topic sequentially. However, the findings from this project suggest that learners understand better how smartphones work when they also think about how they are manufactured and used. Including societal implications of computing can provide learners with useful contexts about how computing is used in real-world problem-solving, and can also help to increase learners’ motivation for studying the subject.

Working together

The final aspect of this research project looked at collaborative problem-solving. The lessons were structured to include time for group work and group discussion, to acknowledge and leverage the range of experiences among learners. At the workstations, learners formed small groups to carry out repairs. The paper doesn’t mention whether these groups were self-selecting or assigned, but the researchers did carry out observations of group behaviours in order to evaluate whether the collaboration was effective. In the findings, the ideal group size for the repair workstation activity was either two or three learners working together. The researchers noticed that in groups of four or more learners, at least one learner would become disinterested and disengaged. Some groups were also observed taking part in work that wasn’t related to the task, and although no further details are given about the nature of this, it is possible that the groups became distracted.

The findings from this project suggest that learners understand better how smartphones work when they also think about how they are manufactured and used.

Further investigation into effective pedagogies to set group size expectations and maintain task focus would be helpful to make sure the lessons met their learning objectives. This research was conducted as a case study in a small number of schools, and the results indicate that this approach may be more widely helpful. Details about the study can be found in the researchers’ paper (in German).

Repair café start-up tips

If you’re thinking about setting up a repair café in your school to promote sustainable computing, either as a formal or informal learning activity, here are ideas on where to begin:

  • Connect with a network of repair cafés in your region; a great place to start is
  • Ask for volunteers from your local community to act as mentors
  • Use video tutorials to learn about common faults and how to fix them
  • Value upcycling as much as repair — both lead to more sustainable uses of digital devices
  • Look for opportunities to solve problems in groups and promote teamwork

Discover more in Hello World

This article is from our free computing education magazine Hello World. Every issue is written by educators for educators and packed with resources, ideas, and insights to inspire your learners and your own classroom practice.

Cover of issue 19 of Hello World magazine.

For more about computing education in the context of sustainability, climate change, and environmental impact, download issue 19 of Hello World, which focuses on these topics.

You can subscribe to Hello World for free to never miss a digital issue, and if you’re an educator in the UK, a print subscription will get you free print copies in the post.

PS If you’re interested in facilitating productive classroom discussions with your learners about ethical, legal, cultural, and environmental concerns surrounding computer science, take a look at our free online course ‘Impacts of Technology: How To Lead Classroom Discussions’.

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