Richard's Tech Reviews

portable-ish air filters

Small filters that are easy to move around from room to room. Canadian prices and sites where available.
Be mindful that you will also have to factor in the cost of replacement filters, as filters typically need to replaced about every six to nine months.

Pure Enrichment PureZone $50
2.7" W x 8.5" H
tiny square foot size

e.g. from the Zon

This is really a personal filter that you would use on an airplane (please check with your airline first).  It can only do a small amount of space around one person.

Levoit Core Mini $50
6.5" x 6.5" x 10.4"
2.2 lbs
172ft² sqft room size

https://levoit.com/products/core-mini-air-purifier

e.g. from the Zon

BlueAir Mini Max $69 to $91
6.8" X 5.9" X 11.4"
2.8 lbs
90 to 216 ft² (sqft) room size

https://www.blueair.com/ca/shop/3654.html

BlueAir Pure 511 $105 to $140
7.9" X 7.9" X 13.4"
4.2 lbs
182 to 432 ft² (sqft) room size

https://www.blueair.com/ca/air-purifiers/blue-pure-511/3560.html

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Levoit Core 300 $190
8.7" x 8.7 x 14.2"
7.5 lbs
219 ft² (sqft) room size

https://levoit.com/products/core300-air-purifier

I mention this because it's widely available but at 7.5 lbs it's not exactly portable.

Problems with audiobook voice control interoperability on smart speakers

Telling your smart speaker to play one of your audiobooks seems like an obvious use case.

And indeed it is supported.  But with vendor-specific lockin only.  Each vendor will only let you voice control audiobooks from their own store.

I'd like to see the library tech community do an interoperability lab test for voice control of audiobooks on smart speakers.

UPDATE 2024-01-12: See updated post Audiobooks on Smart Speakers in 2024.  END UPDATE

Amazon smart speakers

The Amazon voice assistant Alexa can control audiobooks on Amazon smart speakers (e.g. Amazon Echo), but for Amazon Audible only (Amazon owns Audible).

See Audible (an Amazon Company) - Voice Commands for Listening on Alexa Devices.

Google smart speakers

Google's voice control is called Google Assistant, and it can control audiobooks on your Google smart speakers (e.g. Google Nest or Google Home), but for Google Play audiobooks only.

See e.g. Listen to audiobooks on your Google Nest speaker or display and Google Assistant Help - Listen to audiobooks.

Apple HomePod smart speakers

Information below for iOS 17 / iPadOS 17 / HomePod 17.

UPDATE 2023-10-25: Siri on HomePod does support playing audiobooks from Apple Books, if you have Personal Requests enabled.

See blog post Using Siri to Play Audiobooks on HomePod using Personal Requests.

END UPDATE

The situation with the Apple HomePod is even stranger, as it does not currently have any built-in Siri support for playing audiobooks from Apple Books.

It currently only HomePod also supports voice control of Apple Music and Apple Podcasts.

Oddly, you can use Siri to CarPlay audiobooks in your car no problem though.  See Play audiobooks with CarPlay.

Sonos smart speakers

Sonos supports three voice assistants: Sonos Voice Control, Amazon Alexa or Google Assistant.  This would seem like an awesome way to have multiple services available together, just distinguished by saying Hey Sonos, Hey Alexa, or Hey Google.  But that's not how it works, you have to pick one assistant and that's the only one that will be active (I can't see any technical reason why this should be the case, but it is).

However, on Sonos the voice assistants can't control audiobooks.  So you can connect your Sonos to your Amazon Audible account, but you can't use Amazon Alexa to control the audiobooks (again, there is no technical reason why this should be the case).

See How can I listen to Audible using the Sonos app?

Audible with Alexa integration is not currently compatible with Sonos devices.

Similarly, you can't use Google Assistant to control audiobooks on Sonos either.

A nonsensical mess

This is a nonsensical mess.  These services should all just interoperate.

Libby, Spotify and Audiobooks.com

There are other major sources of audiobooks, including OverDrive Libby used by most libraries, Spotify audiobooks, and Audiobooks.com (I think Audiobooks.com is owned by Storytel, it has had a chain of corporate owners).

SIDEBAR: If this looks like a diverse market, the underlying source for most audiobooks is Amazon Audible.  END SIDEBAR

As far as I can tell, there is no support for voice control of Libby or Spotify audioboks.

Audiobooks.com does have an Alexa skill with a long but reasonable command string e.g. "Alexa, ask Audiobooks dot com to play my book" but I assume this only works on Amazon smart speakers.

UPDATE 2023-10-03: TuneIn Premium also has audiobooks.  END UPDATE

September 2023 - Apple HomePod 17 "Third-Party Music Services"

Apple has just, as in just this month in HomePod software version 17, released support for Siri integration with "third-party music services", by which it means anything other than Apple.  This is basically a standard way for Siri to start and control an AirPlay session from an iPhone or an iPad (I don't know if it would work from an Apple TV or a Mac).  It requires iOS 17 / iPadOS 17.  In essence Siri gains the capability to run what are currently manual steps of launching an app on a device, then selecting the content you want to play, and then selecting AirPlay to your HomePod.

Technical Details - SiriKit Media Intents

Apple puts the onus on the apps for "third-party services" such as Audible, Google Play, Libby, Spotify and Audiobooks.com to code support for Siri audiobook control.  This is done using Siri Media Intents.  I found it was clearly explained in the Apple WWDC2023 session Integrate your media app with HomePod (video).  There is specific support for podcasts and audiobooks.

This is actually a good standardized API to make a universal experience across different services.  One can hope that the other services will add this support. 

Technical Details - Personal Voice Recognition

Unfortunately, depending on AirPlaying from a device means that Apple has to be able to tell which device, and to know that you're authorized to play content from that device.  This means that you have to enable what Apple calls Personal Requests for HomePod, a service that requires Recognize My Voice to be enabled.

This means e.g. you won't be able to ask HomePod to play content for someone else, I don't think there is a concept of other authorized users.  If I understand how this works, if your grandfather wants to play audiobooks from his iPad, only he can request it from HomePod (which is also going to make setup and testing more challenging).

HomePod 17 - Whither Apple Books?

It seems like Siri should be able to play Apple Books directly on-device without the elaborate hoop-jumping of AirPlay to an iPhone or an iPad, but at a minimum one would expect Apple Books to be a demonstration of support for the SiriKit Media Intents needed to play audiobooks. 

UPDATE 2023-10-25: Apple Books will indeed AirPlay audiobooks now.  See my blog post Using Siri to Play Audiobooks on HomePod using Personal Requests.  END UPDATE

Prior to HomePod 17, the only option was to use Apple Books with the Shortcuts app.  For authenticated users, Siri will play shortcuts on the iPhone or iPad by exact name match, and shortcut matches have first priority (over-riding even built-in Siri commands).  See iOS 17 - Use Siri to run shortcuts with your voice.

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Crossposted to Science Library Pad.

Don't buy an HP printer

Summary

Don't buy an HP printer.

HP has a dark pattern business model where they want to lock you in to an app-based, subscription-based, surveillance-based business model.  If you refuse to sign up, the printer will literally stop printing.

But you can refuse to participate by not buying an HP printer.

I'm saying this as someone who is surrounded by HP computers, but given that they have embraced this despicable business model for printers, you probably shouldn't buy any HP products anymore at all.

Details

HP printers with an "e" on the end are evil.  No wait, I mean they are mandatory HP+ printers.

You might think you bought a printer, and that you own it, and you can just print to it over USB, but actually HP considers that it is their printer, and they can turn it off whenever they want if you don't obey them.

Even if you print solely over USB, eventually an internal counter will click over and that's it.  It won't print any more.  It will just cough up an "error" message:

Your HP+ printer must be set up using the HP Smart app. Visit (website) to download the app and complete the guided setup.  Any pages you printed were intended for setup and have been exhausted. ...

I will also mention it is profoundly unethical for a programmer to have written the code that disables this printer, but the onus is really on their employer who came up with this terrible business model.

HP argues entirely disingenuously that the onus is on you, the busy consumer, to somehow know that all the "e" printers have this business model and to in the spirit of the free market simply select a different non-"e" HP printer.

Well, what I'm going to do in the free market is never, ever, buy anything from HP again.

Meanwhile, my now-crippled HP LaserJet M140we is going into the garbage, contributing to a stream of electronic waste that this industry cheerfully creates.

If you want more on the history of HP and other printer companies doing terrible things, you can read Boing Boing https://boingboing.net/tag/hp

Emergency Workaround

If you're lucky, the printer may print the very first page (and only the very first page) you send it over USB at startup, so you may be able to print multiple pages using the painful workaround of repeatedly turning the printer on and off and sending one single page after another.

Measuring PM2.5 air quality with a Raspberry Pi and Nova PM SDS011 sensor

Ryder Damen on Tom's Hardware has a straightforward project - How to make a Raspberry Pi Home Air Quality Monitor.  After a small bug fix, it worked well.

My hardware:

• Raspberry Pi 3
• Nova PM SDS011 sensor

Clean Raspberry Pi Install

Hardware:

• SanDisk microSD card
• SanDisk microSD-to-SD adapter
• Apple USB-C SD card reader

Software:

• Raspberry Pi Imager

I just followed the steps on Getting Started - Setting up your Raspberry Pi.

I downloaded the Raspberry Pi Imager, installed it on my Mac, and then installed the default Raspberry Pi OS 32 bit image on my MicroSD card.

I used the advanced options available in Imager by clicking the cogwheel in order to set the Raspberry Pi device name and a non-default username and password for the root account.

Once the MicroSD was reformatted and had the Raspberry Pi OS installed and verified on it, I safely ejected the card (actually I just powered down the Mac, which has the same effect).

Insert the MicroSD and Power Up the Pi

With a new clean install of Raspberry Pi OS ready on the MicroSD, I inserted the MicroSD into the Raspberry Pi and powered up.

I already have a keyboard and mouse on a USB hub (so a single USB-A connector) and a small HDMI monitor.

For networking I just plugged the Raspberry Pi directly into my Ethernet network.

Everything booted up fine, I disabled Bluetooth since it was unnecessary and then I opened a command line and followed the article steps.  I did everything with the root account, which is not a best practice but is the fastest way to get going for this type of single-use experiment.

Follow the Article Steps

After that I just followed the steps in the article.

https://www.tomshardware.com/how-to/raspberry-pi-air-quality-monitor

1. sudo apt-get update && sudo apt-get install -y git

2. cd ~/
   git clone https://github.com/rydercalmdown/pi_air_quality_monitor.git

3. cd pi_air_quality_monitor
   make install

4. make build

make build will take some time. It took about 15 minutes on my Raspberry Pi 3. But you only have to do it once.

5. Connect the SDS011 sensor to the USB adapter it comes with using the provided jumper cable, then
   Connect the SDS011 USB adapter to your Raspberry Pi.
6. There is a bug in the code

You need to edit the file

src/templates/index.html

and change the line (line 35)

$.getJSON('http://10.0.0.172:8000/api/', function(data) {`

to

$.getJSON('/api/', function(data) {`

You can use e.g. the built-in nano editor to do this edit.  (I have also submitted it on GitHub as a pull request - 17 Update index.html)

Otherwise without this change the hardcoded web address (IP address) will cause the web server to fail with a misleading error.

7. make run

8. Navigate to your Pi’s local IP (127.0.0.1) address on port 8000 to view the web server, and a graph of recent measurements of air quality.
   i.e.
   http://127.0.0.1:8000/

IMPORTANT NOTE: This web page does not auto-refresh.  It will start out as a blank graph underneath the text "Raspberry Pi Air Quality Monitor".  You have to manually reload the page (by e.g. clicking the circle arrow) to get the latest data.

Many people were saying their sensor or the code wasn't working, but actually all you need to do is reload the web page.

Any Port in a Particle Storm

I was worried that the four USB ports on my Pi 3 would have some unique numeric binding, but they don't.  With my keyboard and mouse on a single connection through a USB hub, and the SDS011 as the only other USB device, whichever port I plugged the SDS011 into became ttyUSB0 , so it wasn't an issue.

Testing 999

As the reading is normally just steady, I did a -- NOT RECOMMENDED AT HOME -- smoke test by intentionally burning some toast.  This set off my fire alarm and also caused my Temtop M10 PM2.5 sensor to go to its highest reading, 999. 

The on-screen readings from the Nova PM SDS011 responded as expected, so it definitely works.

I also ended up doing an unintentional smoke clearing test, which told me that it takes my air filters 40 minutes to clear the air from unsafe to safe levels.

The Raspberry Pi graph responded to the declining counts as I would expect.  The count wasn't exactly the same as the Temtop M10, but this is to be expected as the Nova PM 2.5 is reading over a shorter time interval.

Going Public

Be aware that this web server is also running on your Raspberry Pi's public IP, not just on localhost.  I solved that problem simply by pulling the Ethernet cable, but you may not have such an easy solution depending whether your Pi is on Wi-fi and what else you are doing with your device.

Conclusion

With the exception of the bug (which the code author really should fix) and the fact that the web page doesn't auto-refresh, this is a quick and easy project to get your own PM2.5 (and PM10) sensor readings.

Bug aside, thanks to Ryder Damen for making such a straightforward no-solder project possible.

Security Note

You should be mindful of the security issues that might be associated with running this as a service on port 8000 of your Pi's public IP (ideally the code should be modified to allow the option of a local service only).

Annex: Buying a Nano PM SDS011

I could only find a wide variety of vendors on Amazon.

I'm in Canada, I got my SDS011 on Amazon Canada from risingsaplings in the States for $55.  I liked that it shipped from Amazon USA, so that I had confidence there actually was a real product and that its shipping would be well tracked.

/risingsaplings-Precision-Quality-Detection-Digital/dp/B0BPQQ24ZR/

You can get much cheaper prices from Amazon Canada by going with other vendors that ship themselves from Canada.  Just search for SDS011.  I can't provide any comment on the other vendors or the reliability of their shipping, I have no idea.

Over the air HDTV in Ottawa

Channels

These channels are free (if you have all the hardware to receive them) but they are regular broadcast television with ads, which may be a bit jarring if you're used to streaming services.

Note that reception is very sensitive to antenna position (including angle), antenna strength, and even to weather conditions.

Make sure your coax cables are solidly connected to the antenna and to the television or external tuner.
Depending on your tuner it may take quite a few seconds (10 to 15 seconds) before it shows a signal for a channel, it won't necessarily tune in instantly.

Also if you're using an antenna indoors, you should step considerably away from the antenna before testing; your body is surprisingly effective at blocking a digital TV signal.

Channel	Station	Service	Resolution	Reception (in my location)
4.1	CBOT-DT	CBC	720p	good
6.1	CIII-HD (CIII-DT)	Global	1080i	good
9.1	CBOFT-D (CBOFT-DT)	Radio-Canada (ICI Radio-Canada Télé)	720p	good, with intermittent issues
11.1	CHCH-DT	CHCH	1080i	good
13.1	CJOH (CJOH-DT)	CTV	1080i	good
14.1	OMNI2	Omni	1080i	good
15.1	CTS-HD	Yes TV (former Crossroads Television System) - religious broadcasting	1080i	good
24.1	TVO	TVO	1080i	good
32.1	CHOT-HD (CHOT-DT)	TVA (TVA Gatineau–Ottawa)	1080i	not getting any signal
43.1	CHRO (CHRO-TV / CHRO-DT-43)	CTV 2	1080i	good
60.1	OMNI1	Omni	1080i	good
65.1	Citytv	Citytv	1080i	good

Antenna

I'm using an Antop AT-402B antenna with the signal gain turned on.  It's big for indoor use (68cm tall) but good at getting a signal.  I have to point it out the window and adjust the angle very carefully in order to get a good signal, as digital TV is line of sight.

Tuner: ATSC vs ATSC 3.0

You will need either a television with a built-in ATSC tuner, or an external tuner.
If it's an ATSC 3.0 tuner that's fine, it will work with regular Canadian ATSC signals (there is no ATSC 3.0 broadcasting in Canada, although you might be able to pick up signals if you're near the US border).

Towers

There are two main digital TV (ATSC) towers in Ottawa (in the National Capital Region, the NCR).

Digital TV is line of sight, more or less.

Ryan Tower

Ryan Tower (Radio-Canada) on Camp Fortune.
Latitude: 45° 30' 9" N, Longitude: 75° 51' 0" W. https://cbctransmission.ca/en/map#289

Herbert Corners tower

Herbert Corners tower.
about 45° 13' 2" N, 75° 33' 49" W