Categories
Current Events What I’m Up To

Watch my live podcast recording with the Thunder Nerds next week!

 

Next Thursday, May 6th at 7:30 p.m. EDT (UTC-4), I’ll be the guest of Tampa Bay tech podcasters, the Thunder Nerds, and you can watch LIVE it as we record!

With 279 episodes so far, The Thunder Nerds have been at this for a long time. I’ll chat with hosts Frederick Philip von Weiss and Brian Hinton about all sorts of things, not the least of which is how their podcast was a key part of the research I did to land my job at Auth0.

I’m sure that a good chunk of our conversation will be about what working at Auth0 is like, authentication and authorization, and possibly the hardware and electronic music dabbling that I’ve been doing lately.

The Thunder Nerds record their podcasts in such a way that you can watch the recording process LIVE on YouTube, and can even type in questions or comments as it’s happening! If you’d like to see how the sausage is made, follow this link next Thursday evening at 7:30 p.m. EDT and watch the fun!

Categories
Hardware

How to choose the right power adapter or charger for your devices

The Bilbo Baggings “After all...why not? Why shouldn’t I keep it?” scene from “Lord of the Rings”, but with Bilbo holding a power adapter instead of the ring.
We’ve all been Bilbo.

If you’re like most people, you probably have a collection of old power adapters and chargers that you’ve held onto, even though the devices they used to power are long gone. You probably thought that someday, one of them might come in handy:

This article will help you figure out if an adapter is compatible with a given device.

A little terminology

Before we begin, let’s make sure we’re using the same words to refer to the different “plugs” on an adapter or charger…

Photo of a power adapter, with arrows pointing out the connector and plug.

  • By plug, I mean the part of the adapter or charger that you plug into the wall.
  • By connector, I mean the part of the adapter or charger that you plug into the device.

With that out of the way, let’s begin!

How to tell if a power adapter or charger is right for your device

A pile of power adapters.

Step 1: Is the adapter’s polarity correct for your device?

Although you could do steps 1 and 2 in either order, I prefer to get the “device killer” question out of the way first. That question is: Does the connector’s polarity match the device’s polarity? Simply put, you want to find out which part of the connector is positive and which part is negative.

In DC current, which is the kind of current that an adapter provides, the polarity determines the direction in which current will flow through the device. You do not want current to flow into your device in the reverse direction.

Here’s a connector and its parts. The sleeve is the outer metal part, while the tip is the inner metal part:

Close-up photo of a power adapter connector, with arrows pointing out the sleeve and tip.

Both your adapter and device should have some kind of label or tag that indicates their polarity. It should be either negative sleeve/positive tip, which is indicated by this symbol…

“Negative sleeve / positive tip” symbol for power adapter connectors.

…or positive sleeve/negative tip, which is indicated by this symbol:

“Positive sleeve / negative tip” symbol for power adapter connectors.

Are the polarity markings on both the adapter and the device are the same?

  • Yes: If the polarity markings on both are the same, you can proceed to the next step.
  • No: If the polarity markings are different, DO NOT proceed to the next step, and definitely DO NOT plug the connector into the device.
  • If the are no polarity markings on the adapter: See the SPECIAL BONUS SECTION at the end of this article.

Step 2: Does the adapter’s connector fit into your device?

With the adapter’s plug NOT plugged into an outlet, can you plug the connector into the device?

  • Yes: If the connector fits, you can proceed to the next step.
  • No: If the connector doesn’t even fit, you can be pretty certain that this adapter isn’t going to work for the device.

Step 3: Do the voltage and current coming from the adapter match the voltage and current required by the device?

If you’ve reached this step, you’ve now taken care of the simple matches: The adapter will push current into your device in the right direction, and the connector fits.

Now it’s time to look at the numbers, namely voltage and current.

  1. Look at the voltage (measured in volts, or V for short) and current (measured in amperes, or amps or A for short) marked on the adapter.
  2. Look at the same values marked on the device.

Do the voltage and current values on the adapter and device match?

  • Yes: If the numbers match, you’re good! You can use the adapter to power the device.
  • No, both numbers don’t match: Don’t use the adapter to power the device.
  • No, one of the numbers matches, and one doesn’t: If only one of the numbers doesn’t match, don’t write off the adapter as incompatible yet. Consult the table below:
…and it’s LOWER than what your device needs …and it’s HIGHER than what your device needs
If the voltage (V) doesn’t match…

MMMMAYBE.

Your device might work, but it also might work unreliably.

Simpler devices, where electricity is converted directly into some kind of result (such as a light, or a speaker) are more likely to work than more complex ones (such as a hard drive, or anything with a processor).

NO! WILL PROBABLY RUIN YOUR DEVICE.

Your device might work. The additional voltage may overheat and damage your device.

If the current (A) doesn’t match…

NO! WILL PROBABLY RUIN YOUR ADAPTER.

Your device might work. Your device will attempt to draw more current than the adapter is rated for, which may overheat and damage the adapter.

GO FOR IT!

The adapter’s current rating states the maximum that it’s capable of delivering.

Your device will work. It will draw only the current it needs from the adapter.

SPECIAL BONUS SECTION:
What if the adapter doesn’t have polarity markings?

Believe it or not, it happens. In fact, I have one such adapter, pictured below:

Close-up photo of the label portion of a power adapter that specifies the manufacturer (Kempower), the model number (KA3A1202000), input and output voltages and currents — but NOT the polarity.
No polarity markings. Not helpful at all.
Tap to view at full size.

As you can see, its label section lists a lot of information, but not the polarity. This means you’ll have to determine the polarity yourself, or you can take a leap of faith.

If you want to determine the adapter’s polarity yourself

If you want to determine the polarity yourself, you’ll need a voltmeter. Set it up to read DC voltage in the range of the adapter. In the case of the adapter above, it’s rated to output 12 volts (V), so I set my meter to read a maximum of 20 V. I put the positive probe inside the connector so that it made contact with the tip, and touched the negative probe to the sleeve. A positive number appeared on the display:

Multimeter being used to measure voltage coming from adapter, with the display showing a positive voltage.

With the positive probe touching the tip and the negative probe touching the sleeve, a positive voltage means that current is flowing from the tip to the sleeve, which in turn means that the tip is positive and the sleeve is negative.

If the number were negative, it would means that current was flowing from the sleeve to the tip, which in turn means that the sleeve is positive and the tip is negative.

In fact, when I put the positive probe on the sleeve and the negative probe on the tip of the same adapter, this is what happened:

Multimeter being used to measure voltage coming from adapter, with the display showing a negative voltage.

Note that the voltage reported is negative. In other words, the current appears to be flowing backwards  — from the negative probe to the positive probe —because I had the probes backwards. Once again, this indicates that current is flowing from the tip to the sleeve, which means that the tip is positive and the sleeve is negative.

If you want to take a leap of faith

If you don’t have a multimeter handy, you can always take a leap of faith and assume that your adapter has a positive tip and a negative sleeve, which is how most adapters are designed. The tip is well-protected and difficult to touch by accident. Since current flows from positive to negative, you prevent accidental shorts and electrocution by making the hard-to-reach tip positive and the easy-to-reach sleeve negative.

Categories
Process

My favorite remix of the “Bobby Hill / If those kids could read” meme

The “Bobby Hill / If those kids could read” meme. Panel 1: Bobby Hill tapes a sign to a classroom’s window that says “Using Jira doesn’t make you agile”. Panel 2: The teacher, holding the torn-down sign, saying to Bobby: “If those project managers could read, they’d be very upset.”
That boy is right. Found via Amir Barylko. Tap to view at full size.

This made me laugh out loud. I’ve seen teams use Jira in some shockingly un-agile ways.

 

Categories
Current Events Tampa Bay

What’s happening in the Tampa Bay tech/entrepreneur/nerd scene (Week of Monday, April 26, 2021)

Here’s your list of tech, entrepreneur, and nerd events for Tampa Bay and surrounding areas for the week of Monday, April 26 through Sunday, May 2, 2021.

This is a weekly service from Tampa Bay’s tech blog, Global Nerdy! For the past four years, I’ve been compiling a list of tech, entrepreneur, and nerd events happening in Tampa Bat and surrounding areas. There’s a lot going on in our scene here in “The Other Bay Area, on the Other West Coast”!

By “Tampa Bay and surrounding areas”, this list covers events that originate or are aimed at the area within 100 miles of the Port of Tampa. At the very least, that includes the cities of Tampa, St. Petersburg, and Clearwater, but as far north as Ocala, as far south as Fort Myers, and includes Orlando and its surrounding cities.

Yes, many of us have had their first (and even second!) vaccines, but we’re not at the point where it’s advisable to return to pre-pandemic-style in-person events. It will happen soon, but in the meantime, I’m restricting this list to online events. In the age of broadband internet, smartphones, and social media, it’s not that hard. Stay home, stay safe, stay connected, and #MakeItTampaBay!

Monday, April 26

Tuesday, April 27

Wednesday, April 28

Thursday, April 29

Friday, April 30

Saturday, May 1

Sunday, May 2

Do you have any events or announcements that you’d like to see on this list?

Let me know at joey@joeydevilla.com!

Join the mailing list!

If you’d like to get this list in your email inbox every week, enter your email address below. You’ll only be emailed once a week, and the email will contain this list, plus links to any interesting news, upcoming events, and tech articles.

Join the Tampa Bay Tech Events list and always be informed of what’s coming up in Tampa Bay!


Categories
Programming Reading Material

Humble Bundle’s “Ultimate Python Bookshelf” bundle is available until Monday afternoon!

At the time this article was published, there are 3 days and 21 hours remaining to get Humble Bundle’s “Ultimate Python Bookshelf” bundle. Depending on how much you’re willing to spend, you can get 3, 8, or 24 books at a deeply discounted price, and some of the money goes to two worthy charities. Read on to find out more…

The books

Depending on how much you pay, you’ll get 3, 8 or 24 books.

If you pay $1 – $9.99, you get these books:

  • The Python Workshop
  • The Statistics and Calculus with Python Workshop
  • Web Development with Django

If you pay $10 – $17.99, you get the books above, along with:

  • Hands-on Exploratory Data Analysis with Python
  • Hands-on Machine Learning with scikit-learn and Scientific Python Toolkits
  • Django 3 by Example
  • Python Automation Cookbook
  • Hands-on Genetic Algorithms with Python

And if you pay $18 or more, you get all the books above, plus:

  • Python Data Cleaning Cookbook
  • Deep Reinforcement Learning with Python
  • Data Engineering with Python
  • Modern Python Cookbook
  • Applying Math with Python
  • Python Image Processing Cookbook
  • Python Feature Engineering
  • Practical Python Programming for IoT
  • Python Algorithmic Trading Cookbook
  • Applied Computational Thinking with Python
  • Hands-on Python Natural Language Processing
  • Hands-on Simulation Modeling with Python
  • Mastering Python Networking
  • Artificial Intelligence with Python
  • Python for Finance Cookbook
  • Quantum Computing with Python and IBM Quantum Experience

Interested? You can order the bundle here.

The causes

All Humble Bundles route some of each bundle’s price to one or more charities. In the case of The Ultimate Python Bookshelf bundle, there are two charities that will benefit:

Doctors Without Borders / Médécins Sans Froniteres: An international, independent medical humanitarian organization that delivers emergency aid to people affected by armed conflict, epidemics, natural and man-made disasters, and exclusion from health care in nearly 70 countries.

Stop AAPI Hate: A national coalition addressing anti-Asian racism across the U.S. The coalition was founded by the Asian Pacific Policy and Planning Council (A3PCON), Chinese for Affirmative Action (CAA) and San Francisco State University’s Asian American Studies Department. Between March 19, 2020 and February 28, 2021, Stop AAPI Hate has received 3,795 reported incidents of racism and discrimination targeting Asian Americans across the U.S..

Wait a minute — there are Packt books. Are they worth getting?

As you were reading this article, you were probably wondering about the issue of the less-than-stellar reputation of Packt’s books and if I was going to raise the issue.

Consider the issue raised, Gentle Reader.

When they were starting out, it seemed that Packt took whatever author they could get to write about the hot tech topics of the moment and rushed those books to market. Over the years, the quality of their authors, review process, and books seems to have improved. I know for a fact that Tampa-based iOS developer Craig Clayton has written some excellent books on iOS development for Packt — because I bought them all.

I decided to buy the bundle. I paid the recommended $25 for these reasons:

  • Some of the money goes to two good causes.
  • At $25 for 24 books, that’s less than $1.05 per book.
  • I’m at the point where I won’t even notice a “missing” $25.
  • I don’t consider it $25 spent, but $25 invested.

That last point requires a deeper explanation:

  • If at least a handful of these books are good and provide me with something that I can use at work, in my own programming projects, or in my articles, I will have collected a good return on my investment.
  • Even if most of them are bad, it will still be a worthwhile investment because the 25 books span a wide array of Python topics, and will give me a better idea of what I don’t know, and better still, what I don’t know I don’t know. I can then look for better sources of information.

As I go through each of these books, I’ll post my findings and opinions here.

How to order the bundle

Once again, Humble Bundle’s “Ultimate Python Bookshelf” bundle is available until Monday, April 26 at 2:00 p.m. EDT (UTC-4). If you wanted to learn Python, sharpen your Python skills, or expand your knowledge of where you can apply Python, this bundle is worth considering.

Categories
Hardware Music Uncategorized

Putting my ’90s synth — the Korg Wavestation A/D — back on active duty

The Korg Wavestation A/D

Front view of the Korg Wavestation A/D rackmount synthesizer
The best damned synth of 1991. Tap to view at full size.

Long before I became an accordion player, I was a synth player. Over the years, I’ve bought and then sold or given away a number of synths, but there’s one that I kept: A Korg Wavestation A/D.

The Korg’s Wavestation A/D is the rack-mount version of the Korg Wavestation EX keyboard synth, which in turn is a revised and expanded model of the original Korg Wavestation. The Wavestation series of synths set itself from the other synths of the era by using a technology called wave sequencing, which could be described as building sounds by pasting sequences of different waveforms together, in a way similar to George Martin’s cut-and-paste approach to the calliope sounds on the Beatles’ Being for the Benefit of Mr. Kite!.

I bought the Wavestation from my friend, Canadian TV/film composer Stephen Skratt, back in 1993, when I was playing keyboards in a band with my schoolmates at Crazy Go Nuts University

Joey deVilla as a university student circa 1992, on stage with the band “Volume”.
Me, circa 1992.

…and I’ve done other live gigs with it (that’s me in the pink wig)…

Stephen Skratt, Joey deVilla, and Karl Mohr jamming on keyboards in 1999.
Stephen Skratt, me, and Karl Mohr jamming on keyboards in 1999.

…and I’ve even used it for some multimedia software projects:

Opening screen of "Welcome to Echo Lake", a multimedia promo for Delrina's "Echo Lake" family album application.
My first software deliverable after graduating from University: A multimedia promo for family album software.

I’ve held onto it ever since, having taken it from Kingston to Toronto, then San Francisco during the dot-com bubble and back, and it’s now at my current home in Tampa.

Simply put, the Wavestation is a beautiful-sounding synth, and even 30 years later, it still sounds great. If you’d like to hear what it sounds like, check out this video by Espen “I am the 80s” Kraft:

Bringing the Wavestation back to active duty

One of my plans for this year is to create a series of videos covering software development and other tech topics including security. Those videos will include music, and I thought that while there’s nothing wrong with licensing some music, why not write my own?

With that in mind, I pulled the Wavestation out of its closet, where it had been sitting, plugged in my small MIDI keyboard controller (the original version of the M-Audio Axiom 25), hooked it up to powered speakers, and turned it on:

The good news was that it still worked. The screen came to life, and pressing keys resulted in those rich Wavestation sounds:

LCD display of Korg Wavestation A/D displaying the name of the currently selected sound: “The Wave Song”.
Tap to view at full size.

The bad news, which I was expecting, was that while the built-in sounds in ROM remained, all three RAM banks which held the sounds that I had lovingly created so very long ago were gone. They had been replaced by copies of the ROM sounds. I no longer had a synth with 200 sounds (or in Wavestation parlance, “performances”, or in general synth terms, “patches”) — I had four identical banks of 50 sounds:

Page 4 from the “Korg Wavestation A/D Performance Notes” manual, which shows the 50 “performances” (synth patches) in ROM.
Page 4 from the Korg Wavestation A/D Performance Notes manual. Tap to view at full size.

I suspected that the battery that maintained the contents of the Wavestation’s RAM had died long ago. I confirmed this theory by tweaking the settings for one of the sounds in RAM, turning the synth off and back on again, then checking my edited sound. It had reverted to a copy of the ROM sound on which it was based.

I’ve done RAM battery replacements on numerous devices over the years, so I felt comfortable with going inside the Wavestation to see how big a chore replacing the battery would be.

The first step was to pop the top panel from the Wavestation. It’s a pretty simple process where you remove six screws — two on each side, and two on the back. Here’s what the inside looks like, as viewed from the front panel:

Korg Wavestation A/D with the top panel removed, as viewed from the front panel.
Tap to view at full size.

Here’s what it looks like from above:

Korg Wavestation A/D with the top panel removed, as viewed from directly overhead.
Tap to view at full size.

If you’ve ever had to replace the battery of an early- to mid-1980s synthesizer with battery-backed memory, you’ve probably dealt with the annoyance of that battery being soldered in. This was probably a cost-cutting measure (compared to today’s prices, synths in the ’80s were quite expensive), and manufacturers probably believed that we’d all upgrade to later models long before those batteries died.

I found a pleasant surprise waiting for me on the Wavestation’s main printed circuit board:

Korg Wavestation A/D with the top panel removed, as viewed from directly overhead, with the battery clip pointed out: “OMG! A proper battery clip!”
Tap to view at full size.

It was a proper battery clip, and in it, a battery that I had in plentiful supply in my tool closet: The ever-lovin’ CR2032 3-volt battery, which powers all sorts of things, including the CMOS RAM on ThinkPads, which I covered in an earlier article.

Close-up of Korg Wavestation A/D main circuit board, with battery clip in center.
Tap to view at full size.

The clip makes it easy to swap out the battery. Pressing against the spring pops the battery out:

Close-up of Korg Wavestation A/D main circuit board, with battery clip in center and battery popped out.
Tap to view at full size.

With the battery replaced, I put the top back on the Wavestation, powered it up, changed the name of one of the sounds in RAM, and powered down and unplugged the Wavestation. I plugged it back in and powered it up, and yes, the change remained in RAM!

LCD display of Korg Wavestation A/D displaying the name of the currently selected sound with its updated name: “IChangedTheName”.
Tap to view at full size.

In case you were wondering what the Wavestation sounds like, here’s a sample:

This recording isn’t of me playing a tune, but just holding down one or more keys. It shows the sort of complex sounds that the Wavestation can make.

Next step: Restore those factory RAM sounds

Even with a new battery, I still have 3 banks of 50 sounds that each are a copy of the 50 sounds in ROM. I’d like to start off with a straight-out-of-the-box 1991 experience and get those factory RAM sounds back. In order to do that, I’ll need a couple of things:

  • The sound data, which thankfully has been preserved by Wavestation enthusiasts and can easily be found online, and
  • A USB to 5-pin DIN MIDI interface to move that data from a computer to the Wavestation:LiDiVi USB-MIDI interface.
  • The SysEx Librarian macOS application to transfer the sound data to Wavestation.

I’ll cover this process in an upcoming post.

Categories
Current Events Tampa Bay

What’s happening in the Tampa Bay tech/entrepreneur/nerd scene (Week of Monday, April 19, 2021)

Here’s your list of tech, entrepreneur, and nerd events for Tampa Bay and surrounding areas for the week of Monday, April 19 through Sunday, April 25, 2021.

This is a weekly service from Tampa Bay’s tech blog, Global Nerdy! For the past four years, I’ve been compiling a list of tech, entrepreneur, and nerd events happening in Tampa Bat and surrounding areas. There’s a lot going on in our scene here in “The Other Bay Area, on the Other West Coast”!

By “Tampa Bay and surrounding areas”, this list covers events that originate or are aimed at the area within 100 miles of the Port of Tampa. At the very least, that includes the cities of Tampa, St. Petersburg, and Clearwater, but as far north as Ocala, as far south as Fort Myers, and includes Orlando and its surrounding cities.

Yes, many of us have had their first (and even second!) vaccines, but we’re not at the point where it’s advisable to return to pre-pandemic-style in-person events. It will happen soon, but in the meantime, I’m restricting this list to online events. In the age of broadband internet, smartphones, and social media, it’s not that hard. Stay home, stay safe, stay connected, and #MakeItTampaBay!

This week’s events

Monday, April 19

Tuesday, April 20

Wednesday, April 21

Thursday, April 22

Friday, April 23

Saturday, April 24

Sunday, April 25

Do you have any events or announcements that you’d like to see on this list?

Let me know at joey@joeydevilla.com!

Join the mailing list!

If you’d like to get this list in your email inbox every week, enter your email address below. You’ll only be emailed once a week, and the email will contain this list, plus links to any interesting news, upcoming events, and tech articles.

Join the Tampa Bay Tech Events list and always be informed of what’s coming up in Tampa Bay!