Long story short but…

You have a Pi3 (B+). You do an os upgrade. Your wifi become unstable and/or stops working…

Culprit is broken update. You need to rollback the upgrade for the network. This is how to do it:

Run:

wget https://archive.raspberrypi.org/debian/pool/main/f/firmware-nonfree/firmware-brcm80211_20161130-3+rpt3_all.deb

sudo dpkg -i firmware-brcm80211_20161130-3+rpt3_all.deb

sudo reboot

For more information – see this link:

https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=249750&sid=0e48494349b8a53c664aaa761cdacbff

A cluster is used to work on distributed computing tasks. So things that need a lot of number crunching. The idea is to run many processes at the same time to make the whole run quicker. Note that often the single processes will take longer because they need to be assigned and marshaled etc (overhead) but running many at the same time makes it worth it.

A GUI , which is what your desktop is, is not suitable for this because there are many different processes that run at random times. The best way to speed up desktop is:

• Faster disk
• Faster/more memory
• 64 bit OS to tack advantage of memory
• Faster processor
• More cores on processor
• More caching memory
• Etc

(the above list is not in any order)

So the short answer is “no”😊

It should be easy – take a screenshot. Well – turns out it is but it’s not exactly the latest and greatest in tools…

“Scrot” is a screen capture tool installed by default on pi os. Nice – but – it is just that – it captures the whole screen. Just press “Prt Scrn” and click – a nice picture saved in your Pictures directory. Fine, all well and good, but what if you only want the active window?

A quick google found the “Gnome Snapshot tool” (gnome-snapshot). It’s simple and effective. I allows you to capture:

• fullscreen
• active window
• area,

How to install?

sudo apt install gnome-screenshot

Run it from the menu, place it on your desktop or change the keybindings for prt scrn.

Hint – to change keybindings – here’s a useful link to Tom’s Hardware:

https://www.tomshardware.com/news/raspberry-pi-custom-keyboard-shortcuts,40215.html

Nice 🙂

The latest version of chromium on raspberry pi OS does not work for Netflix. This is because wildvine (DRM software) is broken.

There are a lot of tutorials and advice on how to get this fixed. The two most popular are to use Kodi and to get chromium media edition.

Using media players (like Kodi) seems a bit of overkill when all you want to do is watch via the browser. It’s also quite a messy way that never worked for me.

By far the easiest way I have found (and also works for Disney+ and probably anything else that uses wildvine) although Spotify is a little unpredictable is to install “pi-apps” and use that to install what you need.

It can be found here:

https://github.com/Botspot/pi-apps

This little wonder also makes visual code easier an a number of other apps to install.

One thing to remember…

If you install chromium media edition, kill all other chromium processes before you start the media edition.

If you don’t then it won’t work.

Hint – you can use htop, put it into tree mode and send sighup to the root chromium process. htop is also very useful to monitor whats going on in your system. If it’s not already installed the sudo apt install htop.

Normally I don’t peel potatoes before cooking them. After all – all the good bits are in the skin. But, when the family decides it likes the new and improved mash recipe that is “fluffier” without the skins – what can I do?

3 Kg of spuds, peeled.

Seems a shame to just compost those skins.

An idea for you…

Make potato chips (aka crisps).

Put the skins in a bowl, pour in some olive oil, add salt and pepper and a bit of fresh chopped rosemary. Use your hands to make sure everything is mixed through well. Put them on a backing try and in the oven at 180 deg C for 30 minutes or so.

Take them out and leave to cool and you get some really good tasting home made chips that you know exactly what went into them. Lower fat? Maybe not but it’s olive oil so it’s healthy – right 😉

I’ve had pi’s for a long time; 2, 3, zero and now the 4. With 4Gb. Cool…

So – is it good enough to replace a desktop?

Quick answer is yes.

Longer answer is as long as you aren’t doing video editing or wanting to play 3d games and stuff that requires a lot of fast processing. For standard day to day stuff – it’s great.

I’ve set mine up with an 8Gb Transcend SD card. The pi was originally supplied with an unbranded 16Gb SD card pre-installed with latest Raspian. I hate to say the amount of time i wasted on that. It eventually loaded and trying to do anything with it was horrendous, slower than the 3b and it kept hanging…

Being the brave soul I am – I decided to use that install to move over to a small second hand SSD I had laying around. Again – the amount of time I wasted!!! Lets not go there.

Moral is:

• Use a good quality, fast SD card
• Don’t use second hand SSDs (or at least check them first)

Anyways – after a lot of messing – I am writing this using WP’s block editor in Chromium. Even starting Chromium previously on the old pi – even with a working SSD was a no go – it would just lock up. So far – this one seems great. I’ve a YouTube video playing and a couple of other windows open. And still running on just the SD card.

Sound quality out of the headphone jacks is great. It does use micro-HDMI so it’s important to not forget that or have kids who hoard cables and don’t mind you raiding their stash. Wifi speed is great as well – this is all down to the much improved architecture of the pi. more UARTs, improved USB bus and not everything going through the same bus.

Temperature wise…

This is maybe a bit of a different story. I’ve no fan on and it’s in a case. The temp is now around 70 deg C as measured by (from https://www.raspberrypi.org/forums/viewtopic.php?t=34994):

/opt/vc/bin/vcgencmd measure_temp

This seems a bit excessive so maybe I need to flash the firmware. I don’t really want to use a fan as this connects onto a few GPIO ports and I want to use a pi cobbler on this for doing some electronics stuff. That said – I will try it and see what it turns out like. I’ve no intention of clocking the thing so well – maybe just leave it.

It does need a 5V 3A USB C power supply. Not a biggie but maybe you will need to get one.

In short – if you are looking for a new working machine, don’t mind getting your hands dirty and aren’t wanting to do processor intensive work then you could do a lot worse than a Pi 4.

Update:

A few days later – I’m still happy with it – I’ve noticed a few issues with the wifi keeping dropping but that could be the range. I’ve also found out that I needed to do a lot of work with the SSD to get it working well. I’ve written about this in another post.

HINT – The SSD wasn’t broken – the USB/SATA interface needed an update.

I plan to use this one the coming weeks as my main machine and see how it all goes. I’ve code to write and things to build so it should get a good work out.

An early birthday present to my self – 4Gb Raspberry Pi 4B. With a case and a fan and a 3A power supply. Also – a vendor supplied 16Gb SD card preinstalled with latest raspbian. and lastly – an external USB 3.0 SSD housing.

What could possibly go wrong?

Reading the documents – it should be easy to boot from the latest version of RaspberryOS (aka Raspbian). Just download the image, un-tar, burn it to the disk, plug the disk in and boot.

Well – erm – nope.

First was the fun and games with the supplied SD card. You would think the vendor would supply an adequate, fit for purpose, unit? Nope. They must have found the nastiest, cheapest, slowest PoS they could. Booting it took for ever. Once booted – I ran the diagnostics because there is no way this can be slower than a 3b right?

Diagnostics are giving almost 50 IOPS! Wow – that fast. NOT. The limit is set at something like 400. Doubtless to say the card was not fit for purpose. But thats ok right – I plan to burn to SSD and boot from that anyways. Using the pi to do this was not the most pleasurable process. It took literally hours.

In the end (and 3 nights later) – I quit with it. I got an old card that I knew worked, flashed the latest image, booted and bang – it was there. Amazing. Even just running from the card was fast. 4Gb really makes a big difference. Chrome would run without killing the entire OS.

Next step – start again with the SSD. Burned the image – booted – nothing.

Waited – nothing.

Tried again – same thing.

Strange.

One thing I found was that it kinda worked if it went through USB 2 rather than 3. Ok – this pointed me to something else…

https://jamesachambers.com/new-raspberry-pi-4-bootloader-usb-network-boot-guide/

The need to update the firmware on the USB/SATA. Did that. Booted – almost same thing. Note – almost – when doing this sort of stuff – keep an extra eye out for things that are slightly different – it’s important.

I would love to provide the link but I’ve managed to loose that one.

Googled again – Now we find out that there is something called UAS. And it’s important. Because on some cheap units – it’s not implemented entirely cleanly. This resulted in finding out way more about the boot process than I ever really wanted to know and also editing a file in the boot directory to add an exclusion for that protocol. Downside is that it would slow my disc down a bit but it would still be way faster than SD.

So I did that.

And guess what?

It worked!

Finally, after a long time and much trying but not giving up. Nice new PiOS on a 128Gb SSD.

Well impressed.

Lessons gained:

• Don’t give up
• Look at the small differences – they may give you a clue.
• Try different ports
• Google and read what you google. Don’t skip the detail.

Update…

These are useful resource links:

Jeef Geerling – pi 4 booting from SSD

https://www.jeffgeerling.com/blog/2020/im-booting-my-raspberry-pi-4-usb-ssd

PI4 USB boot Ubuntu:

https://www.raspberrypi.org/forums/viewtopic.php?f=131&t=278791

Update firmware for JMS578:

https://wiki.odroid.com/odroid-xu4/software/jms578_fw_update

How to improve speeds for PI4 USB

https://www.raspberrypi.org/forums/viewtopic.php?t=245931