Posts Tagged ‘rpi’

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Powering a Pi Zero (2) from your laptop

Friday, November 12th, 2021

The new quad-core Pi Zero 2 has a lot more horsepower than the original Zero and as a consequence it does require more power than the original Zero.

But that doesn’t necessarily means that you cannot power it from an USB port from your laptop.

Can you still power a Raspberry Pi Zero from an USB port of a laptop?

Let’s try. Be reminded all Pi’s are cleverly designed to throttle down, when they experience a power shortage.

To check if your Pi has throttled down:

> vcgencmd get_throttled
throttled=0x0

If you see some other output then 0x0 yes then you’ve had power problems. Otherwise you’re OK.

For the moment, running Raspberry Pi OS Bullseye on a Raspberry Pi Zero 2 powered form an USB port doesn’t show problems by just installing programs and updating the OS.

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Stop your Raspberry Pi from leaking telemetry to Microsoft

Friday, February 19th, 2021

Visual Studio Code is a highly rewarded and much used code-editor from Microsoft.

Microsoft tells you it’s open source, but when you actually install it on your Raspberry Pi 4 or Raspberry Pi 400 as promoted, it suddenly isn’t open source anymore. The installation binaries come packed with some proprietary stuff, like telemetry and tracking.

There is no real reason for that, Microsoft could absolutely disable telemetry by default and offer it 100% open source, but Microsoft doesn’t do that. The company wants to ride on the popular waves of open source without actually practicing it.

Luckily there is a real open source version of VSCode and that is called VSCodium:
https://github.com/VSCodium/vscodium

Somehow Microsoft has managed to get the Raspberry Pi Foundation to add a Microsoft repository with the non-open source version of VSCode.

So when you even do not want to use a Microsoft product, Microsoft is still getting some info about your usage of your Raspberry Pi. In every update your Pi will check with the servers if there is a update.

If you want to stop the spying and tracking, execute this command on your Raspberry Pi:

sudo sed -i 's/^deb/#deb/g' /etc/apt/sources.list.d/vscode.list

Or when you wanna do that remotely:

ssh yourpi "sudo sed -i 's/^deb/#deb/g' /etc/apt/sources.list.d/vscode.list"

This will comment-out the Microsoft repository, and stop checking / leaking usage data to Microsoft.

To install the real VSCode open source version on your Raspberry Pi 4(00):

Install from repository for Debian/Ubuntu/Linux Mint

Recommended way of install. It will update automatically, and now the Gitlab servers will be pinged and not Microsoft’s. šŸ˜‰

That’s not much of a gain, but you get a version without telemetry and tracking and without proprietary code, and that is of course a real win.

See:

https://github.com/VSCodium/vscodium#install-with-package-manager

Install as Flatpak

Not the best choice, but you can install it aside a repository version; to check and test the speed and functionality of Flatpak builds.

Chances are high, you get a slightly older build this way.

flatpak install flathub com.vscodium.codium

flatpak run com.vscodium.codium
The 100% open source VSCodium running on a Pi 400

The 100% open source VSCodium running on a Pi 400

 

The main ten million dollar question remains, why doesn’t Microsoft offer a 100% open source version of VSCode in the first place?

It’s like wrapping a nice sustainable vegetable up in non-degradable plastic. We won’t save the planet with that attitude.

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Using A Raspberry Pi Zero as a webcam without SD card

Thursday, January 7th, 2021

The covid lock-down is sentencing a lot of people to work from home. For that we need webcams, a new pc, better monitorĀ  and other equipment. The Raspberry Pi 400 isĀ  a great and affordable second desktop, it’s the fastest Pi available suited for desktop use. It lacks a camera connector, so you need a Zero to connect a camera board.

So what about reusing that old gadget that was collecting dust in the drawer: a small and cheap Raspberry Pi Zero. If you also happen to own a camera board for that little computer, here is a nice project showmewebcam to turn that cheap computer into a handy webcam. It uses a small Buildroot Linux version and boots really fast.

And now that project has been forked on Github: showmewebcam-usbboot. No SD-card needed. That project will let the Raspberry Pi Zero boot over USB!

If you don’t have a camera board. You can buy a clone version of the v1 board for a few dollars in China, or get a v2 board or for the best results the really great HQ-camera board.

Interested in photography, that High Quality camera board can do some really great macro-photography.

Cheap Raspberry Pi webcam

With the Raspberry Pi Zero costing about 5 euro, and a clone camera board around 3 euro on AliExpress, you can have a very nice and decent webcam for less then 10 euro’s. And that is a bargain. Remember you don’t need an SD card. So save on the hardware where you can.

How does it work?

How does the Pi boot then? Over USB, so you do need the usbboot/rpiboot tool. That is free and opensource software made by the Raspberry Pi organization, a program that makes the Raspberry P Zero boot by pushing the operating system over USB.

Let’s try it out. I’m using an Ubuntu desktop.

Step 1: download showmewebcam-usbboot

Download the latest release .

Unzip it. You will extract a directory called showmewebcam-usbboot.

Step 2: install usbboot/rpiboot

If you have already installed a version of this tool, you can of course skip this tool and jump to step 3.

Download the usbboot/rpiboot, unzip it and build it according to the instructions.

Step 3: Connect the raspberry Pi Zero

(with installed camera board) by putting the USB plug into the middle USB connector.

Step 4: boot the webcam

You can start the webcam by executing the rpiboot tool and pointing it to the unzipped showmewebcam-usbboot directory

sudo ~/usbboot/rpiboot -d ~/showmewebcam-usbboot

After about half a minute booting the Raspberry Pi Webcam will be ready.

How to use the Webcam on the PC

For a quick start, and when no other cam is connected, you can start the webcam with (Ubuntu):

mpv /dev/video0

On a laptop with a build-in webcam the command that you have to issue will be :

mpv /dev/video2

To control your cams on the PC, you need `v4l-utils` (apt install v4l-utils)

To set the resolution

v4l2-ctl --set-fmt-video=width=1280,height=720 -d /dev/video2

To list all video devices:

v4l2-ctl --list-devices

To list the specs of your video devices:

v4l2-ctl --list-formats-ext
ffmpeg -f v4l2 -list_formats all -i /dev/video2

A serial connection will also be available, so you can connect to the Webcam to control the settings and do debugging. That works exactly the same as in showmewebcam

Control the webcam

Finer control offers the camera-ctl tool on the Zero

Connect to the Zero:

sudo screen /dev/ttyACM0 115200 Start the tool # /usr/bin/camera-ctl
Showmewebcam-usbboot - Controlling the webcam with camera-ctl

Controlling the webcam with camera-ctl

Create a stereo webcam

The tool will let you boot more then one Raspberry Pi Zero from the same directory. Just connect the two Raspberry Pi Webcams and start the tool. One will boot, just execute the tool another time and the other one will boot.

The webcams will be available as /dev/video0 (you) and /dev/video2 (your cat) on your Pi400.

Now make that video call with your boss, and ask for a raise. Switch the webcam to your cat the moment you stopped speaking.

What can showmewebcam-usbboot do what showmewebcam can’t do?

Nothing. It can do the same with less hardware, because it doesn’t need an SD card. But is does need extra software, which can limit compatibility. It also boots slower.

It hasn’t been tested that much.

Have fun, try it out,Ā  en let me now your thoughts!

Links:

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Running Raspberry Pi OS on a RPI Zero without SD card

Saturday, January 2nd, 2021

I’ve blogged before about how to boot a Raspberry Pi Zero over USB without an SD card, just powering it with an USB cable in the middle USB connector, and connecting at the same time.

This Christmas I tried it with a new Buster version and a trusty old Raspberry Pi Zero and following the tutorial it’s still running fine with the latest Raspberry Pi OS 2020-12-02-raspios-buster-armhf-lite.img.

Time for some improvements. Updating and upgrading was always possible, but not always successful: you could easily run into disk-space problems.

Default images are shipped/downloaded as small as possible and the default action of booting a Pi with a new image is resizing the root partition to claim all available space on the SD card.

We’re mounting over NFS and of course the resizing did not happen in our case. Luckily, otherwise your guest OS would end up with no space and the Pi would have a partition size of 1GB (or so).

But for upgrades we need more space than the default.

How to increase the image size of an mounted image over NFS?

The image I have downloaded is `2020-12-02-raspios-buster-armhf-lite.zip`, and we have to follow 4 simple steps.

Step 1: unpack it:

unzip 2020-12-02-raspios-buster-armhf-lite.zip 2020-12-02-raspios-buster-armhf-lite.img

Step 2: resize raw image:

Then use qemu-img (QEMU disk image utility) to resize the raw image.

sudo qemu-img resize 2020-12-02-raspios-buster-armhf-lite.img 3G

Here we resize it to 3G, that must be enough to install some extra programs, and download and install updates.

Step 3: set it up as loop device:

sudo losetup -P /dev/loop101 2020-12-02-raspios-buster-armhf-lite.img

These day I set it up as loop101 instead of loop0 as I did in the blogpost of 2018 to avoid conflicting loop devices. Snaps are also installed as loop devices.

Step 4: resize root partition

start gparted with the loop device to resize the root partition.

sudo gparted /dev/loop101

Normally gparted never shows loop devices, but it does when you explicitly start with a loop device.

Then simply push the slider to resize the image, and apply the changes and you’ve gained 900MB of disk-space.

More than enough to do updates and upgrades for years to come.

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Macro Photography with the Raspberry Pi HQ camera and reverse mounted lens III

Saturday, June 6th, 2020

Another try with some extra lighting, and post-processing with Darktable. See my earlier posts about photographing with the Raspberry Pi HQ Camera: part I and part II.

This time I used a special build of raspistill that offers a Field of Merit function to assist focusing. The Raspberry Pi Forum is full of helpful people and is very informative.

Fruit-fly taken with a Raspberry Pi HQ Camera and a reverse mounted Pentax 35mm lens

Fruitflies are the really minuscule flies that hang around you garbage bin, or home plants in the windowsill.

Not sure what the yellow blob is, maybe I caught the fly eating a piece of banana.

 

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Macro Photography with the Raspberry Pi HQ camera and reversing the lens

Wednesday, June 3rd, 2020

The Raspberry Pi is a small computer, but it is a great machine for experimenting with all sorts of technology. The Raspberry Pi Foundation just introduced a new High Quality camera with changeable lenses, so let’s find out if that new camera board can be used for photographing small objects.

FruitflyRaspberry Pi HQ Camera

Fruitfly

And I’m gone a use a rather surprising but cheap technique: reversing the lens.

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