Monthly Archives: May 2019

Memorial Day Sale

via Pololu Blog

We are having a Memorial Day sale all weekend long with site-wide discounts of up to 25%! Check out the sale page for more information. Please note that we will be closed Monday, so orders placed after 2 PM Pacific Time Friday, May 24 will be shipped on Tuesday, May 28th.

Why Buy it When You can Build It?

via SparkFun: Commerce Blog

Working at SparkFun has all kinds of perks, many of which appeal to my need to constantly have a project in process. There are multiple 3D printers on each floor of the building; access to an entire warehouse of electronics prototyping parts; shipping that's better than Prime, since I'm already here every day; and a manufacturing shop that essentially serves as a members-only maker space on nights and weekends (provided you put the tools back and clean up afterward).

Recently, I spilled coffee on my keyboard, and now some of the buttons don't work (I brought home the Multimedia Wireless Keyboard that same day, causing minimal delay in access to full-screen typing). While chatting with my team, they floated the idea that I should build a keyboard to replace the damaged one. We had recently discussed how our Cherry MX Breakout and Cherry MX Switch sell really well, but we didn't sell any keycaps. For in-house projects we 3D-print them, but not everyone has access to 3D printers any hour of the day. Sometimes new product decisions are easy, and everyone loves when meetings end early, so if you haven't already noticed, SparkFun now has everything you need build a full mechanical switch: a breakout, a switch, keycaps and a hookup guide.

Cherry MX Switch Breakout

Cherry MX Switch Breakout

BOB-13773
$1.95
3
Cherry MX Keycap - R2 (Opaque Black)

Cherry MX Keycap - R2 (Opaque Black)

PRT-15305
$0.95
Cherry MX Switch

Cherry MX Switch

COM-13834
$0.95
Cherry MX Keycap - R2 (Translucent Black)

Cherry MX Keycap - R2 (Translucent Black)

PRT-15307
$0.95

Cherry MX Switch Breakout Hookup Guide

April 21, 2016

How to assemble and use the Cherry MX Switch Breakout, allowing you to turn a matrix of mechanical switches into a full-size keyboard!

Now building a custom mechanical keyboard breakout is on my list so I can put the wireless keyboard away for emergency use only – it's too small for my fingers anyway, and has no satisfying clicky sound. This brings to mind a question many makers are familiar with: "Why buy for $X, when you can build it for $10X and a week of your time away from all your other projects in progress, like that half a bike in the garage, the IoT doorbell and the four different prototypes of the SparkFun JetBot AI Kit Powered by NVIDIA Jetson Nano sitting on you desk at work?" Thankfully, the team and I dismissed these thoughts and got down to ordering and soldering. Thank you to those who choose to build incredible projects using SparkFun hardware – we are humbled by your enthusiasm, and we appreciate it!

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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:

Actuator
Type
Max
Dynamic
Load
No-Load
Speed
@ 12 V
Max-Load
Speed
@ 12 V
Current
Draw
@ 12 V
Nominal
Stroke
Length
With
Feedback
Without
Feedback
Light-Duty
(LD) 5:1
15 kgf
[34 lbs]
4.4 cm/s
[1.7″/s]
3.6 cm/s
[1.4″/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
Light-Duty
(LD) 10:1
25 kgf
[55 lbs]
2.8 cm/s
[1.1″/s]
2.3 cm/s
[0.9″/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
Light-Duty
(LD) 20:1
50 kgf
[110 lbs]
1.5 cm/s
[0.57″/s]
1.2 cm/s
[0.48″/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

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!

Weather

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

KIT-15301
$117.95
SparkFun Weather Shield

SparkFun Weather Shield

DEV-13956
$39.95
3
SparkFun Photon Weather Shield

SparkFun Photon Weather Shield

DEV-13674
$34.95
SparkFun ESP32 Thing Environment Sensor Shield

SparkFun ESP32 Thing Environment Sensor Shield

DEV-14153
$60.95
SparkFun Lightning Detector - AS3935 (Qwiic)

SparkFun Lightning Detector - AS3935 (Qwiic)

SEN-15276
$24.95
SparkFun Soil Moisture Sensor (with Screw Terminals)

SparkFun Soil Moisture Sensor (with Screw Terminals)

SEN-13637
$6.95
2
SparkFun Environmental Combo Breakout - CCS811/BME280 (Qwiic)

SparkFun Environmental Combo Breakout - CCS811/BME280 (Qwiic)

SEN-14348
$35.95
12
Weather Meters

Weather Meters

SEN-08942
$76.95
26

Health

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

KIT-14409
$82.95
1
BITalino (r)evolution Board Kit

BITalino (r)evolution Board Kit

DEV-14022
$209.95
SparkFun Single Lead Heart Rate Monitor - AD8232

SparkFun Single Lead Heart Rate Monitor - AD8232

SEN-12650
$19.95
16
Pulse Sensor

Pulse Sensor

SEN-11574
$24.95
12

Music

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

KIT-11177
$37.95
6
SparkFun SparkPunk Sequencer Kit

SparkFun SparkPunk Sequencer Kit

KIT-12707
$62.95
3
WAV Trigger

WAV Trigger

WIG-13660
$51.95
27
MP3 Trigger

MP3 Trigger

WIG-13720
$49.95
12
Tsunami Super WAV Trigger

Tsunami Super WAV Trigger

WIG-13810
$79.95
8
SparkFun Qwiic MP3 Trigger

SparkFun Qwiic MP3 Trigger

DEV-15165
$19.95
2
SparkFun Papa Soundie Audio Player

SparkFun Papa Soundie Audio Player

DEV-14554
$26.95
SparkFun Little Soundie Audio Player

SparkFun Little Soundie Audio Player

DEV-14006
$14.95

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? Yeah...us 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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New products: ACS724 current sensor carriers

via Pololu Blog

We now have new current sensors based on Allegro’s ACS724, the successor to the ACS714 that we have been using for many years. The ACS724 offers a number of exciting improvements over the ACS714, including more current range options (up to ±50 A!), over twice the sensitivity for the ±5 A version, a higher bandwidth for faster response times, and differential Hall sensing for substantially reduced interference from ambient magnetic fields. In quick tests, we saw a variation of around 1% of the full range just from changing the orientation of the ACS714 in space (because of the Earth’s magnetic field), while the ACS724 output stayed steady regardless of orientation. We also tried bringing a small magnet close to each sensor, and its effect on the output was many times smaller on the ACS724.

These bidirectional and unidirectional current sensors are a simple way to gain fundamental insight into the performance of your system. You can use them for closed-loop torque control of actuators, tracking power consumption over time, or even as inexpensive current probes for an oscilloscope. They output an analog voltage that varies linearly with the current passing through them, and because they use the Hall effect to measure the current, they offer full electrical isolation of the current path from the sensor’s electronics. This method of sensing means the sensor can be inserted anywhere into the current path, including on the high side, and because their current path resistance is on the order of 1 mΩ or less, they have minimal effect on the rest of the system.

Five different current ranges are available:

Together with the Broadcom ACHS-712x current sensors we released last month, this brings our full current sensor lineup to thirteen sensors:


ACS709 Current
Sensor Carrier

ACS711EX Current
Sensor Carriers

ACS714 Current
Sensor Carriers

ACS724 Current
Sensor Carriers

ACHS-712x Current
Sensor Carriers
Sensor IC: ACS709 ACS711EX ACS714 ACS724 ACHS-712x
Current range / sensitivity(1): ±75 A / 28 mV/A ±15.5 A / 136 mV/A
±31 A / 68 mV/A
±5 A / 185 mV/A
±30 A / 66 mV/A
0–⁠10 A / 400 mv/A
0–⁠30 A / 133 mV/A
±5 A / 400 mV/A
±20 A / 100 mV/A
±50 A / 40 mV/A
±10 A / 185 mV/A
±20 A / 100 mV/A
±30 A / 66 mV/A
Path resistance: 1.1 mΩ 0.6 mΩ 1.2 mΩ 1.2 mΩ 0.7 mΩ
Bandwidth 120 kHz 100 kHz 80 kHz 120 kHz 80 kHz
Vcc range:(1) 3 V–5.5 V 3 V–5.5 V 4.5 V–5.5 V 4.5 V–5.5 V 4.5 V–5.5 V
Size: 0.82″ × 0.9″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″
Special features: configurable
over-current threshold,
low-voltage operation,
high bandwidth
over-current fault pin,
low-voltage operation
Differential Hall sensing
rejects common-mode fields,
high bandwidth
1-piece price: $9.95 $3.25 $9.95 $9.95 $4.95
1 Sensitivity based on when Vcc is 5V.

Introductory special

As usual, we are offering an extra introductory special discount on the ACS724 current sensor carriers, to help share in our celebration of releasing a new product. The first hundred customers to use coupon code ACS724INTRO can get up to five units for just $5.55 each!