Mini PCs

As you can tell from my Raspberry Pi addiction, I’ve always been fascinated by “mini” PCs (i.e. very inexpensive computers in tiny packages). My latest foray into this world was triggered by the hope that I could set up my living room TV as a Zoom/Webex/Skype/Hangouts space for family get togethers.

I tried using a Pi for this, but it was a struggle, with a mix of failures from missing features to inability to recognize the camera to performance problems, etc. I think if I was only using one service, I probably could have fought to make it work, but it felt like it was going to be too hard to get all of the services going.

This led me to wonder whether I could find a cheap “actual” PC to do the job and coincidentally (or at least I hope it was a coincidence), Amazon decided to point me at a sale on these…

In typical Amazon fashion, this is called

Mini PC, Windows 10 Pro Mini Computer Intel Gemini Lake J4125 Processor(up to 2.7GHz) Desktop Computer, 6GB RAM 120GB ROM, 4K@60fps, Dual Wi-Fi, Gigabit Ethernet, Bluetooth 4.2

On sale, I was able to pick one up for less than 200 $CDN. This is a surprisingly powerful little beast at that price point. It’s about 13cm on a side, making it only a bit larger than a Pi in an Argon ONE case. It’s quiet, it drives my 4K TV fine, it even has an internal slot to add a SATA drive that I filled with a 1TB SSD I had lying around.

Now, I will say it’s not fast. It just barely has enough horsepower to display 4K video, but that did work for the YouTube and Netflix examples I tried.

As to the reason why I bought the box, since it’s running Windows, all of the standard teleconferencing services worked OOTB using a Logitech C920 video camera. I was even able to do a video call through my home NextCloud instance, which surprised me.

Overall I’m quite happy.

Pi, home theatre, and Harmony remotes

Just for grins, I took my Raspberry Pi in the Argon ONE M.2 case upstairs and plugged it into the living room home theatre. I have a small wireless keyboard/trackpad device (that I got with an old QNAP NAS, of all things), which I could use to talk to it. This worked, but the range was terrible — basically, I had to be within 50cm of the Pi for it to work. I have ordered a “real” Bluetooth wireless keyboard/trackpad from Logitech. I’ll let you know how well it works once it shows up.

I also have a Harmony remote, that I’ve been using with the living room gear, and I have to say this has been the best universal remote that I’ve ever had. For grins, I added the Pi as a “Computer” in the app for the remote, and was surprised to find out that the remote wanted to pair with the Pi over Bluetooth. After doing this I am now able to move the cursor and type text on the Pi from the remote app on my iPhone. This despite the fact that the Pi isn’t running Mac OS or Windows. Very cool!

Using the remote, I was able (from my couch) to run Kodi and VLC (both of which worked well) and was able to do some light web browsing. Typing text into the remote app isn’t a good enough experience to want to do anything serious there, but the Logitech keyboard should fix that.

Looks like “argonPi” has a new home.

It works!

Yes, my little temperature sensor app works with the real Sense Hat hardware. Here’s a picture.

Note: that picture is taken in low light so the shutter speed is long enough to catch all of the pixels. You don’t notice the LED scanning with the naked eye, but the camera really shows it (see picture below).

When that picture was taken, it was still in a case with a fan, but it was hard to see the display and the fan noise bothered me. I took it out of the case and added a right angle extender to the GPIO connector on the Pi, so the display stands up, which keeps everything cool enough that no fan is required. I then added four risers and the lid off another old Pi case with some rubber feet, which keeps the board off the ground (and also increases the airflow).

It actually reads a couple of degrees too high, but the accuracy of the readings isn’t all that important as long as it tracks relative temperature values. I tested it by taking it out into my garage (in January), where the temperature dropped, the display turned red, and email was sent. Yay!

(See part 1 for more details about the app.)

Python ?

Wow. I have to say I never thought I was going to end up writing Python programs for fun and (no) profit. That is until I got a Raspberry Pi Sense Hat, at least.

The specific project I’m working on is a remote temperature monitor for an unoccupied site that I’m responsible for, to allow us to react if the furnace goes out there before the pipes burst.

Given the Python library for the Sense Hat, it was basically trivial to build a program that would watch for the temperature to go outside a given range, and send email to me if it did. It took a couple of hours longer than I expected it would to write, but my excuse is that it really was my first Python program. 🙂 (Also, it seems there are quirks around getting accurate temperature readings from the SH, so I’m still tweaking the program, but it’s basically working.)

Given the 8×8 display on the Hat, I even managed to provide a continuous temperature display. 8×8 is not enough pixels to make something look good, so you end up with something like this (as drawn by the Sense Hat Emulator developer tool):

Ugly but readable. For the inquisitive, here’s the “McQ’s First Python Program” version of a function to display the digits:

# Display two digits on the sense hat.

# Digit patterns
digits0_9 = [
    [2, 9, 11, 17, 19, 25, 27, 33, 35, 42],  # 0
    [2, 9, 10, 18, 26, 34, 41, 42, 43],      # 1
    [2, 9, 11, 19, 26, 33, 41, 42, 43],      # 2
    [1, 2, 11, 18, 27, 35, 41, 42],          # 3
    [3, 10, 11, 17, 19, 25, 26, 27, 35, 43], # 4
    [1, 2, 3, 9, 17, 18, 27, 35, 41, 42],    # 5
    [2, 3, 9, 17, 18, 25, 27, 33, 35, 42],   # 6
    [1, 2, 3, 9, 11, 19, 26, 34, 42],        # 7
    [2, 9, 11, 18, 25, 27, 33, 35, 42],      # 8
    [2, 9, 11, 17, 19, 26, 27, 35, 43]       # 9
def display_two_digits (a_number, color): 

    global digits0_9
    black = (0, 0, 0)
    if a_number < 0:
        negative = True
        a_number = abs(a_number)
        negative = False
    first_digit = int(int(a_number / 10) % 10)
    second_digit = int(a_number % 10)
    # set pixels for the two digits
    pixels = [black for i in range(64)]
    digit_glyph = digits0_9[first_digit]
    for i in range(0, len(digit_glyph)):
        pixels[digit_glyph[i]] = color
    digit_glyph = digits0_9[second_digit]
    for i in range(0, len(digit_glyph)):
        pixels[digit_glyph[i]+4] = color
    # set pixels for a minus sign for negatives
    if negative:
        pixels[56] = color
        pixels[57] = color
        pixels[58] = color
    # set bottom right pixel if number is more than 2 digits
    if a_number > 99:
        pixels[63] = color
    # display the result

Of course, you pass in a color for the digits to show, so when the temperature is outside the range, you can show it in red. 😉

Anyway, feel free to point out all the noob Python programming mistakes. I’m always happy to improve.

Site news (again)

So, I realized my last post was probably a bit confusing. The reason I was seeing issues with my older posts was that I had moved them to a new WordPress install because, as it happens, I have once again moved GCW to a new machine. This time, it’s another Raspberry Pi, but this new install has a few nice things going for it:

  1. It’s an 8Gig model. I don’t actually believe I need that much space to run a web server most of the time, but I am running quite a few web apps on it now, and depending on what was going on, I was seeing some peaks on the 4Gig one that were pushing into swap.
  2. It’s a brand new, fresh install on SSD. The old one was still running off a MicroSD card, with the website content stored on a separate SSD. Although this gave me lots of storage for the website, it meant that the install was just that tiny bit more complex than a standard one, so I was forever fiddling with it when updating, etc.
  3. It’s even smaller! I love the size of the finished result. Here’s a picture to give you the idea. Note the size of the ethernet jack on the side for scale.

This time around, I’ve only got 500Gig of storage for the whole install including the website, but I’m no where near hitting that limit yet, so I’m very happy.

Test post

Most of my older posts seem to have extended entries for the titles. I’m not sure what’s going on, but I suspect it’s a side-effect of one too many export/imports. Something to figure out eventually.

Update: I managed to turn it off by hiding post abstracts. I’m not sure why this suddenly started happening however. Hm…

That’s better.

So take a look at this…

I apparently have joined the big leagues, although it’s a bit too early to say for sure. The ping time isn’t great, but I guess it will be good enough. For comparison, here’s what I had before the upgrade:

Ping: 4ms
Down 47.5
Up: 10.4

I’ve tried GeForce Now and it’s like night and day. The game looks basically like it’s running locally now.

As you can see from this post, GCW transferred over seamlessly too.

Now, let’s try some MMOs… 🙂

Fun with Pi

There have been a number of interesting things happening in the Raspberry Pi community lately.

One new hotness is the RPi 4 with 8Gig of RAM, which in addition to having more RAM than you will likely ever need on a machine like this, also has a slightly updated power module that improves the behavior with some USB-C power supplies. It does mean that you can now open too many Chromium tabs to keep track of on this platform too. 😛

Another interesting update is the support for booting off of USB drives, instead of the MicroSD card. This lets you use an SSD over USB3 as your main drive, which is both much faster than the built-in MicroSD, and will have a significantly longer lifespan.

Finally, there is the 64-bit version of Raspian (now renamed as Raspberry Pi OS), which actually matters given you can get a Pi with more than 32bits of address space, but it will likely also improve performance for many tasks once the beta kinks are ironed out.

Anyway, being the RPi geek that I am, here is my latest desktop…

An 8Gig RPi4 with a 500Gig Samsung SSD, in the awesome Argon ONE Pi 4 case, which has both a temperature controlled fan (that is almost always off under normal workloads) and, believe it or not, a working power button that does a safe shutdown! This is definitely the slickest Pi case I’ve used, even if moving all the ports to the back meant making it nearly 50% larger than the Flirc case, which was my previous favorite.

Anyway, even with an SSD that cost more than the Pi and the Argon ONE case together, and the Pi overclocked to 2GHz, it’s still too slow to be a great desktop experience, but it works well enough that I was able to write this post, while watching youtube videos, with several other apps open, including LibreOffice and Gimp, so it’s definitely real.

Google was wrong…

no one wants a pure web laptop.

As someone who has been using Chromebooks for a while…

… I have always tried to push the limits of what you can do with them. More often than not, the limits I hit were caused by one of the core tenets of the platform, that everything you need to do will be done with web apps. It turns out, this was never true, and it’s looking increasingly less likely that it is going to ever become true.

I read a web article a while back called “Is Chrome OS right for you? A 3-question quiz to find out“. The first two questions in the author’s quiz are:

  1. Do you spend most of your time using the web and web-centric services?
  2. Do you have specific local programs that you absolutely need, or could most of the things you do on a computer be accomplished with web-centric equivalents — along with Android and/or Linux apps to fill in any gaps?

At some level, these two questions capture both the history, and the problem with Chromebooks. When Chromebooks were first being developed, the notion that we might end up doing everything on the web was aspirational at best and, more cynically, was an attempt by Google to force people onto a platform they “controlled”. It rapidly became clear that the under-powered, first generation devices that were being built were too limited for day-to-day use, and as the complexity of applications that were being built on the web increased, they couldn’t even handle those web apps well.

Even more telling is that, even if we believed a web-based future would eventually come, what we have actually seen is the world going in a different direction: It’s not web apps that people run, but rather mobile apps. Question two above suggested we would use Android apps to “fill in any gaps”, but it’s Android (or iOS) apps that people typically use now, even if there are web app alternatives.

So what happened? Google added support for Android apps to Chrome, and Apple is in the process of doing the same on their platform. Want proof that it’s a mobile world? Just go take a look at the relative sizes of the Google Play Store and the Chrome Web Store. Go ahead, I’ll wait…

And the funny think about all this, is that yes, Chromebooks are useful now, because they can run the applications people are using, and have large screens and input hardware that makes using those applications easier than running them on phones. Oh well.