HASviolet: Pi Power Considerations

To help celebrate International Pi Day,  the HVDN team would like to share a tiny preview related to our HASviolet project we were expecting to release at the WOPR Summit later this month.

Unfortunately, the blasted COVID-19 virus forced the event to be rescheduled for September 18th to 20th, but we are keeping our project goals on track for release since we have even bigger plans for HASviolet for the rest of the year!

What is HASviolet?

Our project goal was to create an educational platform involving (H)ardware selection, (A)ntenna theory and (S)oftware involving LoRa communications as well as other FSK, GFSK, MSK, GMSK and OOK modulation method applications in the future.

The letters in the word "HAS" may make more sense now, but the color "violet" needs a little more explanation.

We want to promote the use of  900 MHz and above spectrum for both amateur radio and "IoT" hobbyist use so we chose the frequency of 911.250 MHz as our initial project center frequency and namesake.

The HEX value of 911250 is a nice shade of purple and hence, how we came up with the second word in our project name - violet!

Our hopes are that this frequency can become the epicenter for amateur radio experimentation involving LoRa in the United States.

Hardware needs power! 

Releasing this article "just after"  March 14th (AKA "Pi Day") should make our readers guess that our HASviolet project involves the popular Raspberry Pi embedded computer and indeed it does!

You need to have reliable and stable power  for all Raspberry Pi projects and that is what this article will talk about, but just in the context of the Raspberry Pi Zero Wireless device since that is what we are using as part of  the HASviolet project.


Plug in the wall options

The "current" requirements for a Raspberry Pi tend to be at least 2 amps of power and it is advised to use a mains power supply rated at least for 2.5 amps.

Reliable sellers such as Adafruit, SparkFun, MicroCenter, Fry's and even Best Buy or Barnes & Noble in the United States have already ensured what they sell will provide the best user experience.

                      

However, it is a good idea to be cautious when making a purchase online via websites like Amazon or E-Bay since sometimes it is harder to know what you are buying from online sellers.  The best price does not always guarantee the best product!

Here is a list of HVDN approved AC mains 2.5+ amp power supplies from select sellers who sell both online as well as through traditional stores you can visit:

• Adafruit 5V USB Micro Power Supplies 

• SparkFun 5V USB Micro Power Supplies

• Micro Center 5V USB Micro Power Supplies 

• Argon ONE  5.25V 3.0 Amp via Amazon.com 

• CanaKit 5V USB w/switch via Amazon.com 

USB power bank options

A USB power bank is probably one of the best options to power your Raspberry Pi project since you can charge them for portable use by using your plug in the wall adapter or even charge them from any USB port such as one found on any computer.

• You do need to be sure that your power bank is capable of outputting over 2.0 amps of current on at least one of the USB output ports.

• Some USB power banks will indicate this clearly, so be careful about what you purchase.

• A minimum 10,000 mAh capacity power bank is recommended, but 20,000mAh is better.

Higher battery capacity means longer run times. If you plan to travel by air, there is a limit on how large of a power bank you can take with you. Please check airline or local government regulations for details.

In the United States, the FAA sets the appropriate restrictions which the TSA is responsible for enforcing.

In order to match your Raspberry Pi, you will also want one with the USB micro connector rather then the newer USB-C connector so you can use your existing wall mains supply to run your Raspberry Pi directly or to charge your power bank.

Here are three common options to consider purchasing:


HVDN Recommended Option 1: INIU 20000 mAh with  3.0 A output plus USB micro and USB-C input via Amazon.com

HVDN Recommended Option 2: USB Battery Pack for Raspberry Pi - 10000 mAh plus dual high current USB

HVDN Recommended Option 3: Baseus PPDMNA USD PowerBank - After extensive research by one member of the HVDN team, this power bank has proven a good value for the money and comes in different colors. This power bank is also very thin. It can also be shipped from different countries for no extra cost.

This power bank offers true USB-C standard for both charging or output.  A micro USB connector for charging is included alongside the standard USB connector to power external devices.

 

HVDN USB Power Bank Recommendation

There are far too many power bank options available today and we are only sharing three options.

Our recommendation is option 3 based on price and feature set plus you can even get it in pink or blue aside from the usual black or white colors.

Option 1 is great if you need higher capacity and fancy display plus two USB outputs.

Option 2 is is worthwhile if you are looking to add items to your Adafruit shopping cart, who is one of the main suppliers of components found in the HASviolet project you will be able to learn about later this month (Spoiler: Saturday March 28th at 9:11 AM)

pHat Power Options

Modular boards that have the same foot print and 40 pin connector that matches the Raspberry Pi are often referred to as a hat or pHat. A pHat can go under or on top of a Raspberry Pi when using the correct 40 pin connector.

Example of a pHat by pimoroni.com and sold by Adafruit.com.
The EnviroPhat is a collection of sensors with more detail found here

There are many pHat's available for different tasks, but only a few made that can provide a reliable portable power supply.

Here are some options with commentary on ones designed to work with a Raspberry Pi Zero.

pHat Power Option 1:  PiZ-UpTime 2.0 - Not to be confused with the original PiZ-UpTime which only ran on a single 14500 LiPo battery.

The new 2.0 version offers no such restriction and also adds better external on/off control, power in and power out connections along with a fuel gauge to safely power down your RPi when the battery reaches a low amount.

Further details here. The second picture is the first generation PiZ-UpTime for comparison and is not recommended.

Genuine PiZ-UpTime 2.0 

Here is the original PiZ-UpTime for comparison and to show the genuine product compared to imitation copies mentioned later in this article.

pHat Power Option 2:  PiSugar Portable Power Platform - Some members of the HVDN HASviolet team like this product because it is open source as evidence by its Git Hub project page and its overall set of features.

There are two different side batteries available that are the same size of the board and RPi Zero.  A nice feature is a built in visual battery capacity meter via 4 blue LED and the use of the power pads on the bottom of the Raspberry Pi Zero. The PiSugar can also function as a UPS.

3-D printer files are even available to help create different cases easily or to modify for your own use.

Both the 900 mAh and 1200 mAh versions can be purchased via Amazon.com.  The only only drawback of the PiSugar is the small size of its battery which will limit run time compared to a larger power bank.

One member of the HASviolet team has used the 1200 mAh version of this product and easily got 5 hours of continuous run time while running the "beacon" mode of our project with a transmit interval of once every 5 seconds.

pHat Power Option 3:  Generic UPS Power HAT  - There are many generic UPS power hats available for the Raspberry Pi Zero and we have only tested two.

The first one was a generic version of the PiZ-UpTime original product and was a waste of money.

A few years ago, a counterfeit version caused a fault with a Raspberry Pi Zero and was unable to be used for anything else ever again, including the RPi Zero! Please avoid purchasing this product!

The second generic UPS pHat worked much better but only lasted about an hour which was strange considering the PiSugar worked for much longer with a not much larger battery. This one also uses pins from the underside to power your Raspberry Pi.

What to expect from HASviolet?

We hope this brief article on power sources for the Raspberry Pi Zero has you curious on what are we building for the HASviolet project.

Our team thinks that people will want to use the HASviolet project both at home and while traveling, hence us starting to make sure power solutions are something you are already thinking about.

Between now and Saturday March 28th, we will release some additional articles focused on the antenna part of the project along with details relating to Git Hub and other basic necessities so that you can start putting aside some hard earned money to buy the needed hardware for HASviolet!

Be safe in the meantime if you are under self-quarantine or in areas overly affected by COVID-19.

Thanks!

HVDN HASviolet Team

(Joe Apuzzo N1JTA,  Steve Bossert K2GOG & Joe Cupano NE2Z)

HVDN [reset] = Is the "Feather" better?

Embedded computing and open hardware in the form of Raspberry Pi, Arduino and a few others have propelled creativity in the maker, electronics hobbyist, STEM education and amateur radio communities in recent years.

A new format standard called Feather has recently come to market and is very exciting, so lets find out why.

Embedded computing you say?

Since 2012, there have been over 19 million Raspberry Pi sold when combining all the different (and improved) versions sold over the years.

Perhaps the biggest competitor to the Raspberry Pi has been the genuine Arduino family of micro-controller boards with an estimated few million shipped.

Both "embedded computing" ecosystems have spawned various forked versions that illustrate the success these two standards have demonstrated both for hardware and software compatibility.

HVDN [reset] is a sub-series of content that compares
different enabling or disruptive innovations relevant to the
maker, electronics hobbyist and amateur radio community.

One reason that has made both devices popular for add-on device or "hat" accessory development has been standard sizes and pin or GPIO configurations.

This has helped developers create exciting applications quickly & reliably

A new standard called "Feather" has arrived recently and promoted by Adafruit and Sparkfun, both known for providing a range of original add-on products to build even better Raspberry Pi and Arduino based projects.

18 different Feather based products using standard sizing and connections

The [reset] moment

Thanks to Limor Fried and her team at Adafruit along with a number of different vendors like Particle, the new Feather and related terms such as "Feather Board" and "Feather Wing" are poised for a lot of success.

This HVDN [reset] article will explore the "Feather" open hardware ecosystem in  comparison to Raspberry Pi and how it simplified development of our latest project by standardizing on this new small form factor wireless enabled embedded computing standard.

Different sizes of Pi for all appetites

Let's look at how the size of the most well known and current Raspberry Pi offerings look next to each other.

• Raspberry Pi 3B  = 85mm X 56mm
• Raspberry Pi Zero = 65mm X 30mm
• Raspberry Pi Compute  =  67mm X 31mm
• Feather Classic = 51mm X 23mm

Pictured from top left clockwise are the Pi Compute 3 Module,
Raspberry Pi 3 and Raspberry Pi W Zero

Raspberry Pi has been chosen by HVDN to compare against the Feather format because they all offer wireless connectivity.

Arduino has too many variants to compare that have a similar size to Feather but do not offer wireless connectivity. ESP32 and ESP8266 boards have too many versions.

A major benefit with many of the smaller Feather based products
compared to the slightly larger Raspberry Pi Zero is built
in battery charging, power options and connectivity options.

Arduino versions such as the Nano, Micro, and Lilypad along with the Adafruit Trinket are left out of this review since they lack wireless connectivity.

Plucking Feathers

Specifications help drive standards and adoption, so Adafruit has everything documented on its website to make development easy for most everyone.

Standard dimensions of the Feather help
create easy product development and compatibility

Key Feather Physical Dimensions:

• The 'classic' Feather and Wing size is 0.9" x 2.0" with 0.1" holes at each corner.   

• There is one 16-pin breakout strip on the bottom side, centered 1.0" from the left edge.  

• There is one 12-pin breakout strip on the top side, 1.2" from the left side.  

• The spacing between the two strips is 0.8"  

• Don't change the GPIO spacing or location, or you will not maintain compatibility with Wings! 

Key Feather "In/Out" Specifications

Using the Particle.IO "Argon" product as the example, here are the connection details copied from the super helpful datasheet.  Many of the elements found in certain Particle products were even part of the attendee badge at this years Open Hardware Summit to show example of an embedded application in the real world.

So, what is the project?

In 2017  HVDN started to develop a modern field strength meter that has remote sense and analytic capability as featured in the Field Strength Meter Monday series.

After working out the actual sensor part of the project and offering for sale a limited run of stand-alone sensors, we then set to work to redesign the RF signal strength sensor unit to fit as a "hat" onto a popular embedded computing board.

The initial plan was to use the Arduino Nano because it was low cost and easy to program but was soon abandoned because certain versions of it used non-standard USB drivers to update or interface to the device.

A later version looked at standardizing around the STM32 based ESP32 and ESP8266 based embedded computing devices because they both offered integrated battery charging and wireless functionality. They also used the very flexible microPython programming language.

WEMOS ESP32 based Wi-Fi/BLE
4MB microPython IoT device

Quality and version control of these different ESP32 or ESP8266 based boards proved hard to develop easily replicated results around, but working prototypes showed the proof of concept was sound and could be improved upon.

Looking at Feather based options again seemed ideal due to a price drop and additional features. 

It was decided to build this project around the Particle Argon (Wi-Fi + Mesh)  and Xenon boards (BLE + Mesh), with potential support for the Boron (LTE + BLE + Mesh) board at a much later date.

Making projects simple with Feather

The Adafruit Feather based options helped simplify our project design and also allowed even more features to be added!

Future articles will cover microPython coding basics, computer-aided circuit design and fun applications for this exciting project.

Here is the HVDN-FS1....

Open Hardware Summit 2018 Recap

This past week in Boston was the Open Hardware Summit on the beautiful campus of the Massachusetts Institute of Technology.

An estimated 340 people attended based on the number of filled seats for the great presentations that were scheduled across the day.

Alex Camilo and Michael Welling helped create this amazing open source design for an attendee name badge.
OSH Park and Screaming Circuits helped bring this into reality for OHS 2018

Beyond the 17 scheduled educational sessions at the MIT Stratton Student Center, there were also two separate areas for event sponsor demonstrations.

Open Hardware Summit 2018 Highlights

Every attendee received a keepsake "hackable" name tag that includes Wi-Fi connectivity for users to customize the E-Ink display, just like the ones found on the popular Amazon Kindle or in shelf edge displays at Kohl's department store.

More badge functionality can be accessed or enabled by built in FTP or serial connection thanks to the embedded MicroPython based programming along with some additional add on boards also provided to attendees of OHS2018. Other features include temperature sensing, different display fonts, color changing LED lights and SD card storage to name just a few.

The design files, firmware and more details are available on GitHub.  

Additionally, a bag full of goodies including a Particle.io Photon board, DigiKey ruler, stickers, notebooks and a number of other open source circuit projects were given to each attendee too.

Since a few members of HVDN were in attendance for the official event, here are our collective thoughts on the overall OHS2018 experience.

MIT Stratton Student Center was home to the 2018 Open Hardware Summit

Wednesday Evening Pre-OSHWA Networking & Attendee Swag Bag Assembly Gathering

Held at the premier "maker" space in Boston - Artisan's Asylum hosted tours of the member space and was also the backdrop for a pizza party to fuel the volunteers assisting with the assembly of swag bags for attendees of the next day official event.

Pictures of the pre-event have been withheld to protect the identities of all involved since adult beverages may have been also consumed along side the unique veggie crust pizza

The Artisan Asylum was not just home to electronic hobbyist "makers", but others interested
in all sorts of other design projects such as this rather interesting creation.
More about Artisan's Asylum can be found here

This casual gathering with a purpose was a great way to meet others involved in open source projects with pure hobby backgrounds or a blend of commercial and hobbyist areas of focus.

Thursday OSH2018  Event Sponsor Demo Highlights

There were two separate areas for event sponsors to setup demonstrations and talk with attendees of the event.  This staggered approach made it possible for all attendees to roam around the entire event rather than just stay put in one space.  Some of the sponsors that the HVDN team met with included:

• Autodesk  - Offered a sneak peak of Autodesk's EAGLE 9.2.0 software that offers the ability to:

• Import larger component databases from semiconductor manufacturers through vendors such as DigiKey, SparkFun and even more module based offerings.

• Easier ability to create custom components and pin-out labeling

• Enhanced trace and layout tools known as "FANOUT"

• New digital and analog testing tools 

A more detailed explanation and description of updates for version 9.2.0 can be found at http://eagle.autodesk.com/eagle/release-notes   

Many hobbyists seem to have adopted the open source KiCad software or the more simplistic virtual bread-boarding Fritzing program recently, but maybe EAGLE should be reevaluated again by some in the hobby community.

EAGLE is one of many CAD (Computer Assisted Design) programs for those
 interested in EDA (Elecronics Design Automation)

HVDN PERSPECTIVE: As a long time EAGLE user myself looking at alternatives in recent months, faith is now further restored in EAGLE (for now!!) as a commercial oriented program with a great freemium offering for hobbyists or students on a limited budget.

• Tindie.com - Nice discussion about how Tindie can help its sellers reach an audience looking to purchase or experience authentic products rather than foreign copied versions. 

Plus, how Tindie can help individual sellers better manage customer contact and support. Products such as the N5BOC duplex board that HVDN reviewed can be found on Tindie for example directly benefit by value offered by this online store which is part of SupplyFrame.

Ever wonder how much money gets spent by hobbyist "makers"? 
Here is a view into Japan only spending power. Please note this slide was provided by a
charismatic bunny ear wearing attendee of OSH2018 and is not related to Tindie.com

• Great Scott Gadgets - Fantastic discussion with the founder of this company (Michael Ossmann) behind products such as the HackRF One SDR platform, YardStick One and an exciting new product aimed at those looking for a peripheral expansion solution for I/O over USB called the GreatFET.

Learn more about the GreatFET by having a look
at the Great Scott Gadgets website.

Further discussion about other products such as sensor based products similar to the HVDN remote field strength project currently under redesign to accommodate a different Wi-Fi module. This to me was one of the highlights of the event in meeting Michael and talking "shop" about similar topics of interest.

• Red Hat - Handing out premium T-Shirts to those interested in Linux and IoT edge, core compute, or other open source related projects that can harness this robust operating system as an alternative to Microsoft Windows, Apple macOS or other Linux distributions such as Debian or Ubuntu.

Open Hardware Summit logo combines a few common electronic hobbyist components
to form an interesting design to promote the mission and focus of the open hardware community.
Learn more at https://www.oshwa.org/

• OSH Park - One of the best and US domestic provider of circuit board production services. Very valuable insight on working better with them for various projects and design tips to maximize hobbyist dollars. OSH Park is also known as the "purple board" guys, so that may give a hint as to whom HVDN is working with for some of its current and future projects.

Production space for the 300 attendee badges was made available at Artisan's Asylum.
Badges were being soldered the night before and programmed up until the last minute to make f
or a great personalized attendee experience.

Other sponsors there included hackster.io,  MIT Department of Mechanical Engineering,  Circuit Maker and Upverter by Altium, OpenBCI, Digilent, ICFOSS, ShopBot, ChibiTronics  and OctoPart but did not have the time to engage in deeper discussion with them.

Of the scheduled presentations, here is a review of  just a few of them:

• Sara Chipps: C++ API for Kids

Sara provided an excellent overview on how to encourage and inspire children and people of all ages that its never to early (or late) to learn how to code and enable all sorts of projects or dreams. Her company, JewelBots demonstrates the convergence of science, technology, engineering and math also known as STEM.  This is outside of her day job at Stack Overflow.

• Robin Getz: Open Source Software Defined Radio

Robin works for Analog Devices and provided a great basic understanding of what is software defined radio, its impact on the future of RF design and its ADALM-PLUTO evaluation platform available for purchase through ADI directly or re-sellers such DigiKey. 

ADALM-PLUTO SDR development board offered by Analog Devices

• Neil Gershenfeld: How To Make (almost) Anything

Prof. Gershenfeld is director of MIT's Center for Bits and Atoms and covered the future of manufacturing through the lens of Moores Law limitations, self replicating machines and the third digital revolution. It was a fascinating presentation that generated many questions from the audience and three rounds of applause.

The ubiquity of compute enabled devices highlight the amount of underlying impact
technology has on our expanding global economy

• Joseph Apuzzo: MicroPython on ESP32 and LoBo

HVDN's own Joe Apuzzo (N1JTA) had the dubious task of following Neil's presentation and covered the convergence of amateur radio, embedded operating systems and low cost STM32 based micro-controller hardware that can offer high relative performance. 

Particle.io comparison. The Photon, Electron and soon to be available Argon, Boron
and Xenon boards all support microPython and area all very low cost.

Various applications such as MMDVM or IoT through the easy to adopt programming language known as microPython and its performance enhanced graphical interface system known as LoBo can take advantage of both open source hardware and software.   

• Jodi Clark: OpenCosplay, Teaching the Next Generation

Jodi took the audience on a journey through her progression of a hobby interest that turned into a life changing series events that ultimately unlocked a tremendous career opportunity.  CosPlay is the hobby of designing detailed costumes or props found in cartoons, anime, comic books and more that are as realistic as possible.  

While many costumers understand how to create amazing things out of fabric and other materials, many do not know how to integrate electronics to create even better costume experiences.  

Jodi has a popular YouTube channel that teaches some of this and a video of her presentation can be found here

• Nathan Seidle: Founder of Spark Fun (Secret Surprise Speaker)

Nathan was the surprise speaker of the 2018 Open Hardware Summit and shared some recent projects that leveraged or improved upon open source projects.  Nathan first shared how the SparkFun team was able to 3D print different components that formed part of a "safe cracking" robot. 

He then went on to later share in detail how a community of hobbyists helped improve on a machine used in the rapid production of circuit board assembly.  

Sparkfun offers a range of kits, boards, modules and project ideas for
the modern electronic hobbyist and education community

The company Nathan founded has proved a valuable contributor to the hobbyist community over the years and his presentation certainly was exciting to be present for.

• Ted Hayes: How to Put A Neural Network on an Arduino and Why

The topic that Ted covered rivaled the big picture thinking and complexity explored in Neil Gershenfeld's earlier discussion. The Arduino is a capable low cost embedded computing option available today to hobbyists.  

Neural networks partially involve a non-binary state of computing that unlocks amazing potential on low cost hardware, just like what Joe Appuzo covered in his microPython presentation. A more detailed article about neural networks can be found here and a recording of Ted's presentation hopefully will hopefully be made available through OSHWA soon, because I really want to go back and watch it.

• Closing Remarks: Alicia Gibb, OSHWA Director

Alicia thanked so many people who made this event possible and let the audience know that the 2019 Open Source Hardware Summit will likely be in China next year.  HVDN may be organizing a group rate trip for those potentially interested in attending, so please sign up for updates or inquire if there is interest through our various contact forms.

Why Open Hardware Summit & HVDN relate to each other?

Perhaps it would have made sense to explain about what the open hardware movement is all about first before a review of the event, but now I know I have your attention from all the excitement covered above.

Open source design has proven to disrupt and innovate in the data center.
The amateur radio community may be able to innovate by looking at how the open source
hardware movement has already impacted other communication technologies

Within the amateur radio community, there have been heated debates about copying the design of freely available designs for projects such as the ZUMspot.   This is where the opensource overlay into ham radio comes into focus.

This hotspot device was hard to get at times and priced at a level that not everyone could afford for a niche interest.  

These contributed to a friction full experience that hindered adoption and innovation, but at the same time created a competitive opportunity.

Once a few hobbyists copied the original design for this digital hot spot and offered them for sale at more than a 50% price reduction thanks to cheap off shore manufacturing, an entire new market was created that drove additional interest in MMDVM based hotspot purchases thanks to slightly less purchase friction.

Will this new project called "Faraday" be the future of amateur radio?
Learn more here at: https://faradayrf.com/

Additional components for the copycat versions of the original ZUMspot were now high in demand such as cases, power supplies, better antennas, displays and even oscillators!

This never would have happened had there not been open source hotspot hardware available alongside its opensource software needed to create an interesting piece of communication equipment.

Copy of the original ZUMspot version that Joe N1JTA offered some tips for in the
"MMDVM JumboSPOT board: Mods you may need" article.

Amateur radio operators that had experimented with low cost DMR radios such as the TYT MD-380 or Radioddity GD-77 that did not have local repeaters to communicated with others through now had something entirely new to experiment with thanks to this open source derived experience.

The ZUMspot sparked additional purchases and areas of interest due to its open source
design and the competitive opportunities it created

Open source projects have created tremendous amounts of spending that would not have otherwise happened without this contribution to the hobby.

There is a huge opportunity for the amateur radio community to look towards other hobbyist communities in order to bring expertise they do not have related to licensed wireless communication capability.

Open Hardware Summit showcased so much synergy potential for the renewed relevancy of amateur radio outside of what some most associate with amateur radio.

HVDN wants to help promote experimentation through open source hardware, so please use the search cloud on the HVDN Notebook to find other articles tagged with Open Source Hardware in the future.

Feel free to share some links to your favorite blogs, project pages, re-sellers, etc related to open source hardware.