Pi3 Wifi stops working

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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

Will a cluster improve my desktop speed?

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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”😊

Taking a screenshot on Raspberry Pi OS

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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 🙂

How to play Netflix on Chromium

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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

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.

SSD boot for Raspberry Pi 4

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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

Raspberry PI

Raspberry PI, Technology No Comments »

After much delay, I finally got the Raspberry PI up and running.

It’s now running Wheezy on an 8Gb card clocked to a modest 800MHz. It’s slow running X but this I knew.

What really did surprise me was the lack of effort needed to connect it to the wifi. Really was a case of bang in a USB dongle, use the wifi-config tool to set up the SSID info and boom – it’s connected. Well impressed. It’s also stable which is even more impressive.

One thing though to remember – the PI don’t do good on an under powered power supply – so using that old black berry charger rated at 500mA just won’t cut the mustard. Samsung’s USB Travel charger is rated at a very nice 1A. LIKE.

What am I going to do with the PI?

Well – for now – just brush up on Linux and Python etc. I will try turning it into an FM Transmitter. Of course this is probably illegal but the range is only 100m +/- and use a frequency that is not (much) used;) And it won’t be 24/7.

After that?

There are some cool things to do with simple I2C bus stuff and then maybe look at interfacing to Arduino and generally messing around. All good fun.

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