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Getting a Raspberry Pi to boot after cutting it in half

This blog post starts with the question: If I cut the ports off a Raspberry Pi 4 model B, will it still work?

Cut Raspberry Pi 4 model B

My early conclusion? Sorta.

With most Raspberry Pi generations, there is a full-featured model B, and a smaller, trimmed-down model A. The Pi 4 never had a model A, so I thought it would be interesting to see if I could make one. I looked at the Pi 4 with this really cool X-ray tool, as well as using this album of X-ray images from reddit user u/xCP23x:

Xray image of Raspberry Pi 4 model B

The cut was calculated to try to avoid anything important, though as we'll find later it may not have been measured carefully enough.

Automating the Uncommon - AnsibleFest 2021 presentation

At AnsibleFest 2021, I presented a session titled Automating the Uncommon - Ansible automates everything!.

Since watching on-demand versions of the AnsibleFest sessions requires a signup, I thought I'd also post the session to my YouTube channel, so everyone can learn from it without registering. The session seemed well-received, and I hope it shows that, as I state in my 'Rule of Golden Hammers':

Jeff's rule of Golden Hammers - If you know a tool well enough, and the tool is good enough, it's okay to do weird things with it.

I demonstrate how I use Ansible to:

Face detection for my leaf blower

In the class of 'out there' projects, I recently added a little AI to my leaf blower:

Leaf blower with Raspberry Pi on top for AI ML Machine Vision blasting

The short of it: I have a face detection algorithm running which, when a certain individual enters the field of the Pi's vision, triggers a servo that powers on the blower, releasing a powerful air blast.

Red Shirt Jeff gets blasted by air cannon

I've been wanting to play around with face detection on the Pi for some time, but the Pi Zero I use in most of my camera projects is seriously underpowered for this kind of work.

CM4Ext Nano

So when Harlab (Hardware Laboratory) told me they'd like to send me a CM4Ext Nano board for testing, I thought it'd be the perfect opportunity to play with machine vision on the Pi.

Raspberry Pi KVMs compared: TinyPilot and Pi-KVM v3

In a strange coincidence, the authors of TinyPilot and Pi-KVM both emailed me within a week of each other and asked if I'd be interested in one of their KVM devices.

TinyPilot vs Pi-KVM v3 Price comparison

Michael Lynch, founder of Tiny Pilot, said he'd used some of my Ansible work in building the TinyPilot update system, and Maxim Devaev, of Pi-KVM, liked my Pi open source content, and wanted to see what I thought of the new v3 kit that's currently on Kickstarter.

I took them both up on the offer, and dug into both devices.

Both have HDMI and USB inputs, so you can plug them into any Mac or PC and get full control, up to and including BIOS/UEFI settings, remote desktop management (with no software on the managed computer), and mounting of USB ISO images for re-installing an OS or maintaining a system.

Monitoring my home's air quality (CO2, PM2.5, Temp/Humidity) with AirGradient's DIY sensor

A few months ago, I found this Hacker News post about the AirGradient DIY Air Quality Monitor. I had already been considering buying an AirThings Wave Plus sensor to monitor my home's CO2 levels, but the high price and limited 'ownership' of the data coming from it turned me off.

AirGradient DIY Air Quality Sensor - Focus Stacked by Jeff Geerling

So I built two AirGradient DIY air quality monitor boards (see above), and integrated them into my Prometheus + Grafana home monitoring setup I've been using to monitor other things in my house:

AirGradient DIY Grafana Dashboard for CO2 PM2.5 Temperature Humidity monitoring

Modeling my Grandpa with 3D Photogrammetry

Today I released a video about how—and why—I 3D Printed my Grandpa and put him on my bottle of ketchup. Watch it here.

I sculpted a bust of my Grandpa in high school, gave it to my grandparents, got it back after he died and my Grandma moved out of her house (I wrote a tribute to my 'Grandpa Charlie'), and I kept on moving it around my office because I didn't have room for it:

Grandpa bust - terracotta by Jeff Geerling in 2001 - original statue
Grandpa by Jeff Geerling, terracotta, 2001.

I decided it had to go, but asked my extended family if anyone wanted the statue (thinking it would be sad to destroy it). One enterprising cousin suggested he could 'copy' the statue in smaller form using photogrammetry:

I made a custom ceiling mount for my camera

I shoot the 'A-roll' for my YouTube videos with a Sony a6000 and a small Glide Gear TMP 75 smartphone teleprompter:

Tripod setup with teleprompter and Sony a6000

Until recently, I had these mounted on a tripod just off the back corner of my desk:

Tripod in the way

Some people mount semi-permanent camera rigs on a pole on their desks (example), but my adjustable-height desk (by UPLIFT) is not rock solid, so sometimes when I'm typing or accidentally bump the desk, anything mounted to the desktop wobbles.

For lights, monitors, etc., a little wobble isn't a problem. But even with image stabilization in my camera, the wobble becomes noticeable if I have the camera physically attached to my desk.

Why build a Raspberry Pi Cluster?

Raspberry Pi Cluster next to a banana for scale

After I posted my Raspberry Pi Blade server video last week, lots of commenters asked what you'd do with a Pi cluster. Many asked out of curiosity, while others seemed to shudder at the very idea of a Pi cluster, because obviously a cheap PC would perform better... right?

Before we go any further, I'd say probably 90 percent of my readers shouldn't build a Pi cluster.

But some of you should. Why?

Well, the first thing I have to clear up is what a Pi cluster isn't.

Note: This blog post corresponds to my YouTube video of the same name: Why would you build a Raspberry Pi Cluster?. Go watch the video on YouTube if you'd rather watch the video instead of reading this post!

Uptime Lab's CM4 Blade adds NVMe, TPM 2.0 to Raspberry Pi

A few weeks ago, I received two early copies of Uptime.Lab's CM4 Blade.

Uptime Lab's Raspberry Pi CM4 Blade Computer with NVMe SSD

The Blade is built for the Raspberry Pi Compute Module 4, which has the same processor as the Pi 4 and Pi 400, but without any of the built-in IO ports. You plug the CM4 into the Blade, then the Blade breaks out the connections to add some interesting features.

A 1U rackmount enclosure is in the works, and 161 of these boards would deliver:

  • 64 ARM CPU cores
  • up to 128 GB of RAM
  • 16 TB+ of NVMe SSD storage

That's assuming you can find 8 GB Compute Modules—they've been out of stock since launch almost a year ago, and even smaller models are hard to come by. More realistically, with 4 GB models, you could cram in 64 GB of total RAM.

Raspberry Pi OS now has SATA support built-in

After months of testing various SATA cards on the Raspberry Pi Compute Module 4, the default Raspberry Pi OS kernel now includes SATA support out of the box.

SATA card and Samsung SSD with Raspberry Pi Compute Module 4 IO Board

In the past, if you wanted to use SATA hard drives or SSDs and get native SATA speeds, and be able to RAID them together for redundancy or performance, you'd have to recompile the Linux kernel with SATA and AHCI.

Sure you could always use hard drives and SSDs with SATA to USB adapters, but you sacrifice 10-20% of the performance, and can't RAID them together, at least not without some hacks.

There's a video version of this post: SATA support is now built into Raspberry Pi OS!