Monthly Archives: May 2019

KiCon 2019, Chicago

via WyoLum Blog

The seed for my long overdue tour of the US was planted when I realised that Hearsh’s Graduation at the University of Pittsburgh and KiCon 2019 were happening practically on the same weekend. Thus were set in motion the gears that culminated on my current Whirlwind tour of the US. I was looking forward to both events with equal anticipation. First step was to take a couple of small hops halfway across the world.

One small hop, then a large one !

At WyoLum, we have been using KiCad since 2010, when it was still quite rough around the edges, but suited us better than other existing EDA even with all of its shortcomings. Since then, I’ve been consistently using KiCad for all of our hardware projects. And I love conducting workshops and boot camps to help people get started with KiCad. Over the years, at many locations in India and the US, I’ve conducted quick 2 hour introductions, as well as long, 2 ½ day intensive boot camps. This summer trip, I planned to do more of the same wherever possible. But I wasn’t sure what I could talk about, or do a workshop on, at a KiCad conference attended by novices, power users, developers and everyone in between.

I’m using FreeCAD to design a custom, 3d printed case for a photo booth project we are working on right now, and it seemed like an apt topic to talk about at KiCon 2019 – “Mechanical CAD integration with electrical CAD”. We built our first photo booth in 2013 for the Open Hardware Summit, and an updated version for MAKE: magazine in 2016. The latest version is a huge improvement on the earlier versions – more about it in another blog post – and I’ve spend a lot of time trying to design an enclosure for it. Just like us, I figured everyone else who builds circuit boards will sooner or later require an enclosure, and using KiCad + FreeCAD seems like a killer combo.

While at the conference, I set up our TouchSelfie photo booth, and we managed to get some great snaps. Here’s a LINK to the photo album.

There are two separate use cases where FreeCAD is useful when designing electronics. One is to build 3D models of electronic components, align these models with their KiCad footprints, and embed them within the KiCad project. The other is to design an enclosure around the completed KiCad board which can then be 3D printed, laser cut or machined / injection moulded. In both cases, the basic FreeCAD workflow remains quite similar, and my talk focused on providing a quick walk through of the commonly used workbenches. I also briefly talked about two special workbenches which are very useful – KiCad Step Up Tools and CADquery workbench. The former, in particular, provides very strong integration between KiCad and FreeCAD. Embedded below is the video from my talk at KiCon 2019, and a link for the slides deck.

VIDEO : “Fast 3D Model Creation Using FreeCAD” – Anool Mahidharia (KiCon 2019)

Slide deck, KiCon 2019 (Google Slides)

It’s not easy covering such a lot of ground within under 30 minutes, so I was glad to have a chance to do a longer workshop the next day where I (hopefully) guided a roomful of folks get started with the basics of FreeCAD such as constrained sketches, boolean operations and parametric modeling.

KiCon 2019 has been a great experience for me, and I met a ton of interesting people from all around, and made a lot of new friends. I’m hoping it becomes a recurring event and look forward to the next edition. Videos of the talks are being uploaded on YouTube on the Contextual Electronics channel. Do check them out, give a thumbs up, and share them around.

New 5:1 Glideforce light-duty linear actuators

via Pololu Blog

We have filled out our line of 5:1 Glideforce Light-Duty Linear Actuators to include all of Concentric’s available lengths by adding 2″, 6″, 8″, and 10″ versions, with and without feedback, to our existing 4″ and 12″ options. The low gear ratio makes these our fastest (but weakest) linear actuators, capable of lifting up to a few dozen pounds at speeds up to 1.7″ per second (44 mm/s) at 12 V. For stronger but slower options, we have versions available with a 10:1 gear ratio or 20:1 gear ratio.

This brings our total selection of light-duty actuators to 36 options:

@ 12 V
@ 12 V
@ 12 V
(LD) 5:1
15 kgf
[34 lbs]
4.4 cm/s
3.6 cm/s
1.2 A –
3.2 A
2″ LACT2P-12V-05 LACT2-12V-05
4″ LACT4P-12V-05 LACT4-12V-05
6″ LACT6P-12V-05 LACT6-12V-05
8″ LACT8P-12V-05 LACT8-12V-05
10″ LACT10P-12V-05 LACT10-12V-05
12″ LACT12P-12V-05 LACT12-12V-05
(LD) 10:1
25 kgf
[55 lbs]
2.8 cm/s
2.3 cm/s
1.2 A –
3.2 A
2″ LACT2P-12V-10 LACT2-12V-10
4″ LACT4P-12V-10 LACT4-12V-10
6″ LACT6P-12V-10 LACT6-12V-10
8″ LACT8P-12V-10 LACT8-12V-10
10″ LACT10P-12V-10 LACT10-12V-10
12″ LACT12P-12V-10 LACT12-12V-10
(LD) 20:1
50 kgf
[110 lbs]
1.5 cm/s
1.2 cm/s
1.2 A –
3.2 A
2″ LACT2P-12V-20 LACT2-12V-20
4″ LACT4P-12V-20 LACT4-12V-20
6″ LACT6P-12V-20 LACT6-12V-20
8″ LACT8P-12V-20 LACT8-12V-20
10″ LACT10P-12V-20 LACT10-12V-20
12″ LACT12P-12V-20 LACT12-12V-20

Single-sensor selfies with the Flying Pixel Portrait Camera

via Arduino Blog

While most cameras use an array of sensors to quickly capture an image, Niklas Roy presents a different take on things with his Flying Pixel Portrait Camera.

This installation invites participants to place their head under a shroud for nearly a minute and a half, while a computer-controlled projector scans one’s face pixel by pixel. Reflected light levels are recorded with a single light-dependent resistor (LDR) via an Arduino flashed with Firmata, allowing it to interface with the Processing sketch that runs the device without any extra software.

The results are 50×50 black and white photos. It’s also possible to produce color images, which means triple the wait time—and a bit more noise.

The Flying Pixel Portrait Camera uses a video beamer, a single photo resistor, an Arduino and a PC for taking photos of people’s faces. The beamer ‘scans’ the image by projecting a small white square onto a person’s face inside an otherwise completely dark chamber. While the projected square slowly moves over the entire face, the photo resistor captures the reflected luminosities. This generates a proportional analog electric signal which is digitized by an Arduino and transmitted to the PC. As the PC also controls the position of the projected square, it can now construct an image based on the different brightness values that it receives, one pixel at a time.

Gearing Up for Summer

via SparkFun: Commerce Blog

Although it is snowing in Colorado as we speak, most schools are getting out this week (if they aren't already) and with summer just around the corner, we're here to help kickstart your calendar for the season with some of our finest summer-appropriate projects, tutorials and products. You may love to get outdoors, but you can still find a project to accompany you. Maybe it's a stormy day and you need an activity to pass the time. Perhaps it is way too hot outside to be comfortable, which makes for the perfect excuse to stay inside and cool. Whatever you reason may be, check out all the parts and projects below to get a better idea of what to get started on!


Summer is the best time to get outside, which also makes it perfect for getting accurate temperature, humidity and barometric readings. We have multiple options to get you started, including an incredibly handy kit utilizing micro:bit!

SparkFun micro:climate kit for micro:bit

SparkFun micro:climate kit for micro:bit

SparkFun Weather Shield

SparkFun Weather Shield

SparkFun Photon Weather Shield

SparkFun Photon Weather Shield

SparkFun ESP32 Thing Environment Sensor Shield

SparkFun ESP32 Thing Environment Sensor Shield

SparkFun Lightning Detector - AS3935 (Qwiic)

SparkFun Lightning Detector - AS3935 (Qwiic)

SparkFun Soil Moisture Sensor (with Screw Terminals)

SparkFun Soil Moisture Sensor (with Screw Terminals)

SparkFun Environmental Combo Breakout - CCS811/BME280 (Qwiic)

SparkFun Environmental Combo Breakout - CCS811/BME280 (Qwiic)

Weather Meters

Weather Meters



What better time of year focus on fitness? We offer a multitude of different options to find your heart rate, electromyography (EMG) and oxygen readings, all from very simple set-ups!

MyoWare Muscle Sensor Development Kit

MyoWare Muscle Sensor Development Kit

BITalino (r)evolution Board Kit

BITalino (r)evolution Board Kit

SparkFun Single Lead Heart Rate Monitor - AD8232

SparkFun Single Lead Heart Rate Monitor - AD8232

Pulse Sensor

Pulse Sensor



Be the life of the party when you bring your very own, custom audio player to your next BBQ, party or impromptu get-together! People will be sure to ask how you made it, but be warned, they'll also probably hit you up in the future when one of their electronics breaks down (if they don't already)!

SparkFun SparkPunk Sound Kit

SparkFun SparkPunk Sound Kit

SparkFun SparkPunk Sequencer Kit

SparkFun SparkPunk Sequencer Kit

WAV Trigger

WAV Trigger

MP3 Trigger

MP3 Trigger

Tsunami Super WAV Trigger

Tsunami Super WAV Trigger

SparkFun Qwiic MP3 Trigger

SparkFun Qwiic MP3 Trigger

SparkFun Papa Soundie Audio Player

SparkFun Papa Soundie Audio Player

SparkFun Little Soundie Audio Player

SparkFun Little Soundie Audio Player


Project Ideas

To round out the post, here are a few random projects we've created that can be put to good use in the warmer months! If you don't see one you like, we have hundreds more over on our Learn Site.

Interactive Smart Mirror

February 8, 2016

Build a smart mirror that displays weather data using the Intel® Edison.

DIY Light-Up Shoes

September 28, 2017

This tutorial provides everything you need to know to make your own light up high top sneakers!

Wireless Audio Bluetooth Adapter w/ BC127

December 14, 2017

Build a custom wireless audio Bluetooth adapter using BlueCreation's BC127 and add it to your old speaker system!

Raspberry Pi Zero Helmet Impact Force Monitor

March 8, 2018

How much impact can the human body handle? This tutorial will teach you how to build your very own impact force monitor using a helmet, Raspberry Pi Zero, and accelerometer!

LED Crystal Goddess Crown

September 27, 2017

Follow this tutorial to make your own Crystal Goddess Crown with LEDs!

Building an Autonomous Vehicle: The Batmobile

December 6, 2016

Documenting a six-month project to race autonomous Power Wheels at the SparkFun Autonomous Vehicle Competition (AVC) in 2016.

Light Up Pennant with E-Textiles

September 17, 2015

Show your school spirit, geek pride, or fandom with a light up pennant using the LilyTwinkle or LilyPad Arduino.

Sunrise Machine with the Tessel 2

October 13, 2016

Are you to sleepy to enjoy a sunrise on a brisk morning? too! No worries, with a Webcam, a Tessel 2 and a bit of code you can sleep in and catch the sunrise at your leisure with the Sunrise Machine.

These are just a few ideas to get you started this summer. Maybe you want to build a drone or robot? How about tackling machine learning and artificial intelligence? You can even stay in and read a book! Regardless, let us know what you are making this summer!

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Arduino SIM, the new cellular connectivity service for the Arduino IoT Cloud

via Arduino Blog

Arduino SIM: 10MB Free Data for Up to 90 Days!

The new Arduino SIM offers the simplest path to cellular IoT device development in an environment familiar to millions. The cellular service, provided by Arm Pelion Connectivity Management, has a global roaming profile; meaning a single Arduino SIM can be used in over 100 countries worldwide with one simple data plan.

The Plan

  • Arduino SIM comes with 10 MB of data free for the first days 90 days,
  • One simple subscription at 5 MB for $1.50 USD per month*.
  • Global roaming profile – enjoy the same amount of data traffic for the same price wherever you are operating the device around the world.
  • Cellular connectivity to the Arduino IoT Cloud – monitor and control your devices anytime, anywhere.
  • Ideal for connected devices on the go or in areas without reliable WiFi.

*The monthly Arduino SIM plan is currently only available to U.S. residents

By partnering with Arm Pelion Connectivity Management, the cellular service has a solid foundation for users needing to scale form a single to large numbers of devices in the future.

At launch, the Arduino SIM will allow users to send data into the Arduino IoT Cloud, while later in the year they will also be able to use the Arduino SIM to connect to the Internet via a combination of webhooks and APIs.

Arduino SIM is initially rolling out with support for the Arduino MKR GSM 1400 (3G with 2G fallback) – a 32-bit Arduino board supporting TLS and X.509 certificate-based authentication through an on-board secure element and crypto-accelerator. Arduino IoT Cloud makes it possible for anyone to connect to these boards securely without any coding required, but they are still programmable using open-source libraries and the traditional Arduino IDE.  

Now available to pre-order from the Arduino U.S. Store!

The NSFW Roomba that screams when it bumps into stuff

via Raspberry Pi

Hide yo’ kids, hide yo’ wife — today’s project is NSF(some)W, or for your kids. LOTS OF SWEARS. You have been warned. We’re not embedding the video here so you can decide for yourself whether or not to watch it — click on the image below to watch a sweary robot on YouTube.

Sweary Roomba

Michael Reeves is best known for such… educational Raspberry Pi projects as:

He’s back, this time with yet another NSFW (depending on your W) project that triggers the sensors in a Roomba smart vacuum to scream in pain whenever it bumps into an object.

Because why not?

How it’s made

We have no clue. So very done with fans asking for the project to be made — “I hate every single one of you!” — Michael refuses to say how he did it. But we know this much is true: the build uses optical sensors, relays, a radio receiver, and a Raspberry Pi. How do I know this? Because he showed us:

Roomba innards

But as for the rest? We leave it up to you, our plucky community of tinkerers, to figure it out. Share your guesses in the comments.

More Michael Reeves

Michael is one of our Pi Towers guilty pleasures and if, like us, you want to watch more of his antics, you should subscribe to him on YouTube.

The post The NSFW Roomba that screams when it bumps into stuff appeared first on Raspberry Pi.