Jeff GeerlingModify

2025-06-14 22:01:00

How I monitor and control all my powered devices (Zigbee + HA)

Any time I show power consumption graphs for the SBCs, computers, and servers I test, I get a number of comments asking for more details about the setup.

It's quite simple, really: using my Home Assistant Yellow's built-in Zigbee radio, I connect a number of ThirdReality Zigbee Smart Outlets to it, and then I use ApexCharts Cards to add graphs of power consumption over time on my Home Assistant dashboards.

2025-06-06 22:00:39

Sipeed NanoCluster fits 7-node Pi cluster in 6cm

Sipeed's NanoCluster is a tiny compute module clusterboard with room for up to 7 tiny computers.

Each slot has two inline M.2 (NGFF) slots which accept either a custom-designed SoM (System on Module) or an adapter board to adapt a standard Compute Module form-factor board into the slot (as pictured above).

One end has a large fan for cooling, and the other end has power and IO. You can power the board via either PoE++ (60W) or through USB-C PD (65W). Or both, with redundant power fail-over.

2025-06-06 12:19:42

Self-hosting your own media considered harmful (updated)

I just received my second community guidelines violation for my video demonstrating the use of LibreELEC on a Raspberry Pi 5, for 4K video playback.

I purposefully avoid demonstrating any of the tools (with a suffix that rhymes with "car") that are popularly used to circumvent purchasing movie, TV, and other media content, or any tools that automatically slurp up YouTube content.

2025-05-30 22:08:54

A limited-time flavor: Blue Raspberry Pi

The most unique Raspberry Pi I own is a limited-time flavor: blue raspberry. And no, this isn't the Brazilian version, or the red Chinese version. This blue version is one of 1000 blue Pis that were made to celebrate Raspberry Pi's first anniversary, 12 years ago.

2025-05-16 22:03:10

Using GPS for the most accurate time possible on a Mac

I'm deep in the rabbit hole of all things time and timing. One step on any modern horologist's journey is GPS time.

NIST just put NIST-F4 online, accurate to within 2.2e-16 ppm (that's 0.00000000000000022 seconds. The clock is described in Metrologia thusly:

The fountain uses optical molasses to laser cool a cloud of cesium atoms and launch it vertically in a fountain geometry.

2025-05-16 04:10:43

Installing an outdoor GPS antenna for more accurate time

I've been deep into time and timing lately (more shenanigans coming tomorrow), but today I posted a video covering the install of a PCTEL GPS/GNSS antenna at my studio.

I put up the antenna after realizing how indoor GPS reception is just never that great, due to a variety of factors (like multipath propagation and interference), even if I placed my antennas up in the plenum space right under the roof. Of course, it doesn't help that my studio has a metal roof :)