Tag: Raspberry Pi

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My Pi 400 Travel Desktop

Good Morning from my Robotics Lab! This is Shadow8472, and today I am trying out my Raspberry Pi 400 as a lightweight daily driver. Let’s get started.

rPi 400

The Pi 400 is a special edition of Raspberry Pi – essentially a Pi 4 built into a keyboard. It’s missing a USB 2.0 port (made up for by the keyboard) and the 3.5mm audio jack. In theory, the miniature keyboard computer is perfect for travel – assuming you have a screen at your destination that is.

Choosing a Distro

My first thought was to try installing Arch. A brief search found an Arch on ARM project as vanilla Arch only supports x86 architecture. The instructions involved formatting a drive on the terminal. I bought a 256 GB SD card and did so on the first convenient rPi install I had – Kali linux.

It took a few failed attempts to install Arch. The pure open source method that reportedly works on the regular Pi 4 didn’t on my Pi 400, and the standard method wasn’t cooperative when installing a login manager and any of a few desktop environments. Running on a time crunch before leaving on a trip, I switched to DietPi, another lightweight distro I’ve worked with before for, but for a much different project. As with Arch, MATE was uncooperative, so I settled with XFCE. Special thanks to Balena Etcher for a special warning when formatting large drives.

Packing For a Trip

To shortcut setup, I copied my browser and LibreOffice data from my main desktop. LibreOffice worked for me, but didn’t carry the full dark mode – a problem I’ve encountered before, but ultimately decided to live with.

Firefox ESR –as installed from DietPi’s hedged garden– refused to accept my profile. Regular Firefox –installed from the apt repositories– was up to date and started as expected. Notably, it included my extensions – especially Bitwarden, my password vault.

A screen was not procured at my destination, so I packed one from home. The missing audio jack was also problematic, so I packed my Blue Yeti with plans to disable voice monitoring. For redundancy, I packed an HDMI monitor, but busted the ​​styrofoam while stuffing it into the slightly wrong box. As of writing, I have done nothing with sound.

Deployment

We left on our trip. Upon arriving, I found my over-packed tech bag lacked a long enough HDMI cable. I borrowed a longer one. The monitor signal kept flickering. For a while, I assumed I was overloading the Pi with a couple hundred browser tabs, but after a power blink and several reboots, it came out that the HDMI was bad. We bought a replacement, and it’s been working properly since.

Ejected Challenges

Arch wasn’t the only thing I had to back off from. I brought a couple additional Pi 4’s to have myself a nice, little network with Pi-Hole ad blocking, but Wi-Fi strength and configuration challenges meant those were both a no-go.

Another challenge I want to pull off is playing Stardew Valley. I copied the files over back home, but haven’t had time to try the conversion I found yet.

Takeaway

Finishing a project as a rule is better than stalling an overly ambitious one. I have an on-the-go workstation, even though it still lacks polish.

Of special interest, this week marks the 6th anniversary of my Robotics Lab. And some months ago, I decided I wanted to do a Sabbath year cycle. I’ve proven that I can be consistent at posting, even if I feel my quality slips some weeks. The facts of the matters is that weekly posts are getting a bit repetitive for me, so for the next year, I’m only going to post when I finish a major project, such as when I have the full software suite I have in mind for my homelab. After that, perhaps I’ll stick to monthly. We’ll see in a year’s time.

Final Question

Setting up a travel computer on the quick was a bit of a trick. What must-haves would you include in a similar package?

I look forward to hearing your answers in the comments below or on my Socials.

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I Went From Command Line to Discord Voice on Raspberry Pi

Good Morning from my Robotics Lab! This is Shadow_8472 with a side project of the week. Let’s get started!

Starting From the Basics

I found myself in need of a separate Discord account connected to a voice server this past week. With one account on my main computer and myself unable to use Discord mobile, I chose to work with my Raspberry Pi 400. I downloaded a build of Debian 12 for the Pi, flashed it with balenaEtcher, and it booted to the command line with no Internet access.

I was challenging myself by trying to maintain a conversation while setting things up. As I lacked a free Ethernet connection, that meant working with Wi-Fi. I only got as far as failing to get wpa_supplicant up while only using far fewer tools than were assumed by the tutorials I was using. In the end, I moved a connection over from my main computer temporarily.

Desktop Environment

The MATE desktop environment has been good to me for my old laptop. Once I got it installed on the Pi, even it felt a bit heavy – a note for next time, I suppose. I was able to easily connect to Wi-Fi and restore my desktop’s Ethernet.

Firefox went on next because Discord doesn’t have a client for ARM processors outside the same Android app I cannot use, but the browser version loaded. It didn’t see my USB microphone, and neither did Firefox even after bumbling around with allowing web pages to see my mic. Only then did I find and enable the PulseAudio daemon so Firefox could see my mic and pass it to Discord.

pulseaudio --start

Since I was working quick and sloppy as root, I had to use the following instead:

pulseaudio --system

Takeaway

I can tell my skills are improving. I believe a full Arch install may be in my future.

Note

An interesting problem I keep running into is the system clock. Extreme low-end computers frequently don’t include the circuitry to measure time while power is otherwise off because of monetary cost and circuit board real estate. This week, it meant I had to reboot after connecting to Ethernet, though I could probably have found a way to manually set it.

Final Question

What is the craziest project you’ve ever done starting with a command line?

I look forward hearing your answers on in the comments below or on my Discord server.

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Family Photo Chest Part 13: Early Prototype Workflow

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am merging a couple projects into one and hoping they stick. Let’s get started!

Overview

I’ve been piecing bits of my photo trunk project workflow together now for way too long. Right now, the architecture is looking like I’ll be scanning sets of pictures to a directory on a Network Attached Storage, then I can use a cluster of dedicated microcomputers from another unfinished project to separate and deskew the raw data into individual files. These files will then live permanently on the NAS.

Progress is rarely linear though. My end goal for this week hopped around quite a bit, but in the end I felt like I did nothing but figuring out how not to proceed: ground work with no structure. Routers are hard when you’re trying to learn them on a schedule!

Lack of Progress

In a perfect world, I would have been well on the way to configuring a cluster node by now. In a less unreasonable one, I would have had my Pi 4 OpenWRT ready to support the cluster. Late-cycle diagnostics chased me into an even more fundamental problem with the system: Wi-Fi connectivity.

During diagnostics, I’m learning about how different parts of the system work. Physical connection points can be bridged for a single logical interface, and Ethernet cables can support separate ipv4 and ipv6 connections. I can’t configure the Ethernet (on either logical interface) the way I want because that’s how I’m connecting to the Web UI and SSH. I end up stuck using two computers besides the two router Pi’s (OpenWRT and a Raspian hack router that actually works) because I don’t like switching my Ethernet cables around on the switch, but I need to do that anyway when I have to copy a large block of text. In short: the sooner Wi-Fi gets working, the better.

I understand I am essentially working with a snapshot. It’s been tidied up a bit, but bugs still exist. Wi-Fi is apparently one of those things that’s extra delicate; each country has its own region, among other complexities. On the other hand, I don’t know if that’s actually the case, as diagnostics are ongoing.

Takeaway

I’m probably going to work on this one in the background for a while. The OpenWRT help forum’s polish at least in part makes up for routers being dull to learn. If it takes too long, I do have other projects, so I may need to replace the cluster with a more readily available solution.

Final Question

Have you ever had upstream bugs that kept you from completing a task?

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“Beowulf Cluster:” Part 6: OpenWRT Installed

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I’m installing OpenWRT Linux router distribution on a card for a Raspberry Pi 4. Let’s get started!

Background

A while ago, at the beginning of lockdown, I was gifted a few microcomputers I wanted to arrange into a cluster, maybe even turn them into a model supercomputer. I was planning on using OpenWRT, but it wasn’t –and technically still isn’t– available for the Pi 4 outside the use of snapshots. I compromised by configuring a minimal Raspian installation, but I’ve yet to figure out how to program the firewall to disallow computers on its Local Area Network (LAN) from going anywhere online without my say so in addition to keeping them hidden from the Wide Area Network (WAN).

My efforts back then were still possibly the most useful project I’ve done to date: I’ve been using that card as my main Wi-Fi receiver for my workstation. I conjecture it should be just fine with a Pi 4 (1 GB RAM), but since all my more qualified Pi 4’s are busy, my fancy Pi 400 has been serving in that capacity.

Installation

As noted above, OpenWRT for the Pi 4 is only officially available as a snapshot. These builds often lack recommended packages, including any GUI I might want to explore. This is where community builds come in. My research converged on one by wulfy23.

The GitHub’s readme’s took me a while to understand, in part because of all the options. I gathered that there were “factory” builds and “system” builds. Factory builds are for fresh installs, and system builds are for upgrading existing systems. At that time, there were as many as three builds for download, and choosing the right one seemed almost arbitrary.

My first time installing, I totally forgot to check the provided SHA256SUM before unzipping it and dd’ing it to SD card and booting. I landed in a terminal that kept mixing the prompt with other messages. Reaching out to a support thread on the OpenWRT forum, I learned about the web interface, and how to connect to it.

The URL I was given failed every time, even my workstation alone with the router on my switch. I ended up going directly for the IP: 192.168.1.1. I was met with an inadequate dark mode I couldn’t find the settings for. I expect they’re probably there, and I spent a small amount of time looking for them by tossing reasonable sounding URL’s around and hoping for the best, but comparing notes among other tabs in the interface, I think the chances of happening across the specific one I need are slim.

Installation Take Two

I went through the same process another day, and found only a single version for download from the same place. The SHA256SUM checked out, and instead of unzipping it first, I learned about zcat, a little command line utility that can unzip a file to be piped into another command. I piped it directly into dd per an example installation I spotted my first go around installing OpenWRT.

I provided a root password and found a different theme that didn’t force a partial dark mode on me in short order. I found built in tools for ad blocking network wide, settings for managing network interfaces, and most importantly to this project: a fire wall. Alas, the fire wall remains something I have little practical understanding of. I’d like to believe I have a mid-range understanding of what it can do, but my only real hope is copying lines and hoping they do what I want – the last thing one wants in a firewall intended for actual security. No. A custom firewall is at least a week in and of itself.

Takeaway

I really like trying to do two weeks worth of topics in a single week. It usually doesn’t work. Granted: I did have a rusty introduction to both parts of the topic I wished to fuse into one this week. I’m looking forward to remembering zcat in the future.

Final Question

What neat, little tips and tricks have you picked up during a larger project?

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Family Photo Chest Part 12: Early Prototype Workflow

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I’m recounting the tale of my first working prototype, and how I ruined it before getting it to actually work. Let’s get started!

Pi4 8GB and Cards

I am now the owner of a Pi4 with 8GB of memory, the highest end Pi available at the present time. When I unboxed it, I put it directly into a case with a fan powered by GPIO pins. Some day, I’ll want to benchmark its cooling against my Pi 4 with the huge heatsink case and passive airflow.

The cards I had on order never came in, and their listing vanished in the meantime. I ended up with some 64GB cards from Gigastone that are supposed to be better on paper, but I’m not in a position to benchmark the Raspberry Pi use case. While these new cards only have one SD adapter between them –I’ve been using SD adapters for labels– they did include a USB adapter. It’s only 2.0, though.

Manjaro ARM

I have not fully settled on what distro to go with for this project. TinyCore is great for starting projects, but I have a hard time finishing it there. For the time being, I’ll be prototyping from my Manjaro ARM card. Whenever I need to reset, I can boot a Pi to Raspberry OS and arrange for a direct dd from my master Manjaro card to the newer, larger card.

Side note: While performing my first wipe, I noticed dd did NOT automatically expand the partition like I thought it did. Once I have things working better, that may be a possible improvement to look at for a new master Manjaro card.

Prototype GIMP Configuration

First order of business was installing GIMP and XSANE plugin for GIMP. They worked first try, but XSANE only recognized a shared network printer all in one with a scanner built in, ignoring the local USB scanner I cannot seem to arrange access permissions for correctly. I think I spent half my time this week on this problem exploring dead ends.

The most important missing piece to the puzzle has been a script called Divide Scanned Images. With it, I can feed it scans containing multiple pictures, and it can separate and crop them automatically with the option to deskew (rotate to vertical) if an appropriate utility is found. Link to blog about script: how-to-batch-separate-crop-multiple-scanned-photos. Linked on that page in a comment by user Jan is a Linux-compatible version of Deskew (I have yet to get it to work).

Eager to test what I did have working, I went ahead with using the scanner on the network. I had someone put some picture stand-ins on; I got two seed packs. To my annoyance, the separation script appears to only work with pictures on file and not freshly scanned in, making it a completely separate process. As mentioned above, Deskew refused to work. I suspect I either didn’t put it in the right place or I was working with a copy compiled for an x86 processor while on an ARM based system, though it could be as simple as shadows from the seed packs.

Struggling With the Scanner

I find SANE to be an ironic acronym: Scanner Access Now Easy. I still don’t have Linux scanners figured out. I know there’s an easy way with security implications I’ve stumbled my way through before. I also have learned that differences between distros make the Ubuntu page I keep getting thrown to for help useless in parts. Whenever I post for help on Discord, someone else comes along with another question and mine gets buried.

Along my journeys, I’ve learned about a scanner group. I tried adding it to my profile, and somehow managed to get what appears to be a fake group. After a long time trying to figure out how to safely remove it so I could add the real one, I managed to remove myself from all my default groups including my ability to use sudo, and I don’t believe a root account is set up on this card. It even said the incident would be reported. Any such black mark never had a chance to be transmitted over the Internet –WiFi was down for USB scanner diagnostics– before I dd‘ed the master copy back over it.

Another attempt had me searching through the local files for answers. sane-find-scanner and anything looking at the USB port directly can see the scanner right away, but scanimage -L to list devices SANE sees comes up with nothing when off the network. I can’t reproduce my exact path on the laptop I’m working from, but I found a tip to check /etc/sane.d/ for appropriate config files. If I understand epson.conf there correctly, my problem is either elsewhere, or I need both a product ID and a device ID, the later of which I still have no idea how to locate.

Revised Workflow Proposition

In the light of GIMP seemingly not wanting to split pictures live in memory, it may be a good idea to offload that task to a more powerful computer that can handle two Pi’s operating scanners and saving to a network share hosted on an SSD before saving the pictures to GoldenOakLibry. Touch up can then happen in-place.

Takeaway

While I’m glad to have gotten a subpar prototype operational, it’s only about 60% of the process demonstrated at once. Still, it was the missing pieces demonstrated, and the toughest spot was exactly where I expected from past experience. This is already Part 12 of this ongoing series, and I want to finish before another 12 parts go by. Any month may be the month, and no matter how down I feel at the end of work on it, I still made a major goal this week.

Final Question

What was the biggest mistake you’ve ever made but still had a minimal effort fix for?

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