Posts

Showing posts from July, 2020

Boot Raspberry Pi 4 from USB SSD without SD Card

Image
The Raspberry foundation has recently published a new beta version of their firmware for the Raspberry Pi 4 Model B, which supports booting from USB. Finally. This means no SD Card is not required anymore, the bootloader can be loaded from an USB mass storage device! This is a major improvement! 

Note: This approach only works with the official Raspberry Pi OS, either 32bit or 64bit. Ubuntu, unfortunately does not yet work, as there are changes required to uBoot, uncompressing the kernel image, etc. to support booting from the USB Drive on Raspberry Pi. This is a step by step instruction loosely based on Jeff Gerling's I'm booting my Raspberry Pi 4 from a USB SSD and James Chambers's Raspberry Pi 4 USB boot config guide for SSD flash drives. Please note that the second article was published before USB boot was possible and thus is using a workaround of loading the bootloader from SD and the root filesystem from the SSD.
In the following tutorial, we'll make sure that  you&…

Cytron Heatsink Review for Raspberry Pi4 with Stressberry

Image
The Raspberry Pi4 had some thermal issues in the past and people were advised to add at least a heatsink when running CPU intensive workloads. A firmware update has improved the situation to a great extend, but decided to attach a heatsink with a fan, just to be sure.
So let's see if the heatsink+fan from Cytron is actually doing anything good on the Raspi. So I wanted to gather stats for the following situations No heatsinkHeatsink with fans turned ofHeatsink with fans turned on.And I wanted then to look nice make sure that they also capture the temperature before and after the stress test. That's why I used Stressberry and loosely followed the tutorial from Core Eletronics.
But first things first: Update your system sudo apt update sudo apt full-upgrade
And install Stressberry sudo apt install stress pip3 install stressberry --user Detour #1Should the above command fail with an error similar to the one below, your are missing some packages to be able to build from source …

Powerful Image to PDF Conversion with OCR for free with WSL

Image
I decided to move as much as possible to cloud and I'm quite happy with the decision. Especially the OneDrive mobile app helps with scanning of paper documents. Its free for up to 10 pages and includes OCR
But what about the tons of images that are actually scans from documents? Sure, converting images to PDF is easy, and there are a lot of tools (usually already included in your favorite OS or browser as a virtual PDF printer). So what's the catch then? Well, encapsulating a image in a PDF does actually not really utilize the strengths of the PDF format which is storing text. And without text, no modern OS will be able to index your files to make your digital archive searchable.
My requirements were relatively simple Run OCR on existing PDF files and save the text in the existing PDF (or replace it)Convert on a image file and convert it to a PDF with embedded text from OCRConvert and merge multiple image files to one PDF with embedded text from OCRRunning the above use cases s…