power

Review of Raspberry Pi's PoE+ HAT (June 2021)

The PoE+ HAT powers a Raspberry Pi 3 B+ or 4 model B over a single Ethernet cable, allowing you to skip the USB-C power adapter, assuming you have a PoE capable switch or injector.

Unfortunately, I can't recommend this new PoE+ HAT for most users, at least not in its current state.

For more background on PoE in general, and a bit more detail about the board itself and my tests, please watch my video on the PoE+ HAT—otherwise scroll past it and read on for all the testing results:

Using the Shelly Plug to monitor Starlink's power consumption

I recently wrote about using a Raspberry Pi to remotely monitor an Internet connection, and in my case, to monitor Starlink (SpaceX's satellite Internet service).

Power Consumption Grafana dashboard with Shelly Plug US power usage coming through

One other important thing I wanted to monitor was how much power Starlink used over time, and I was considering just manually taking a reading off my Kill-A-Watt every morning, but that's boring. And not very accurate since it's one point in time per day.

Shelly Plug US

Review: Innergie PowerJoy 30C USB-C Wall Charger

tl;dr: The Innergie PowerJoy USB-C charger is a solid power adapter for charging via USB-C and USB-A simultaneously. If you have a high-power-draw device like a MacBook Pro, then the adapter may have a little less utility, but if you use a smaller USB-C device and need to charge both it and a USB-A device, then this is one of the most compact and well-built adapters I've used.

Innergie PowerJoy 30C USB-C wall power adapter

A month ago, I received an email from Innergie asking me if I'd like to review their new USB-C charger they were releasing. I had just returned from a business trip and was slightly regretting only having my MacBook Pro's included USB-C charger, which has one USB-C port. Charging my phone meant plugging my laptop into the AC adapter, then plugging a Lightning cable into my MacBook Pro.

I didn't want to have to bring along a separate USB-A power adapter, but it would've been more convenient, since I could charge the phone separate from the laptop.

Review: AUKEY 30,000 mAh USB-C Portable Charger (with USB A, USB C, Micro USB)

Jeff's Rating: 3/5

tl;dr: Slightly pricey, could use a better interface for charge status, and holds 20% less than the advertised capacity, but the still-plentiful amount of stored energy and the ability to charge via USB-C or USB-A makes this a versatile and potent power pack for the price.

Ever since the mid 90s, when I was able to lug around 'power bricks' with my then-amazing PowerBook 190 and 180c (hand-me-downs from relatives), I've been hoping for a reasonably-priced power brick that would double my laptop's battery life, affording me the ability to work all day even when I'm doing a ton of crazy things, like building a ton of VMs and Docker images.

AUKEY 30000 mAh Portable Charger

Review: Satechi USB Type-C inline Power Meter (ST-TCPM)

tl;dr: It's a power meter, not a protection circuit. It works well and is worth the money if you need to monitor power consumption, but it's made of plastic and doesn't feel like it can take a beating, so handle with care.

For some time, I've used a PowerJive USB Power Meter to measure the charging rate of various USB power adapters, and even things like how much power a Rasbperry Pi uses under load.

Raspberry Pi Zero - Conserve power and reduce draw to 80mA

[Update 2015-12-01: I bought a PowerJive USB power meter and re-tested everything, and came up with ~80 mA instead of the ~30 mA reported by the Charger Doctor that I was using prior. This seems to be more in line with the results others were measuring with much more expensive/accurate meters in the Raspberry Pi forums: Raspberry Pi Zero power consumption. I've updated the numbers in the post below to reflect this change. Seems the Pi Zero is only incrementally better than the A+—still excellent news, but not nearly as amazing as I originally thought :(]

Yesterday my post comparing the Raspberry Pi Zero's power consumption to other Pis hit the Hacker News front page, and commenters there offered a few suggestions that could be used to reduce the power draw even further, including disabling HDMI, changing the overclock settings, and futzing with the lone ACT LED.

Raspberry Pi Zero - Power Consumption Comparison

tl;dr: The Raspberry Pi Zero uses about the same amount of power as the A+, and at least 50% less power than any other Pi (B+, 2 B, 3 B).

On November 26, the Raspberry Pi foundation announced the Raspberry Pi Zero, a $5 USD computer that shares the same architecture as the original Raspberry Pi and A+/B+ models, with a slightly faster processor clock (1 Ghz), 512 MB of RAM, and sans many of the essential ports and connectors required for using the Pi as an out-of-the-box computer.

Raspberry Pi Zero - new with adapter cable
The Raspberry Pi Zero - quite a small Linux computer!

The Constraints of in-home Website Hosting

I run dozens of websites, and help build and maintain many others. Almost every one of these sites is served on a server in one of the giant regional data centers in New York, Atlanta, Seattle, LA, Dallas, Chicago, and other major cities in the US and around the world.

These data centers all share some very important traits that are key to hosting high-performing, highly-available websites:

  • Power redundancy (multiple power feeds, multiple backup power sources)
  • 1 Gbps+ upload/download bandwidth (usually with many redundant connections)
  • 24x7 physical security, environmental controls, hardware monitoring etc.

When I choose to host the Raspberry Pi Dramble website in my basement, I get almost none of these things. Instead:

Review: Intocircuit Power Castle 15000 mAh Dual USB portable charger

Jeff's Rating: 4/5

tl;dr: Slightly pricey, but it'll be worth it when you need it!

I've carried a small external USB battery pack with me for the past few years, ever since I started relying on my iPhone as my only camera, phone, reading device, and emergency-backup-Internet device. And there have been many times where I would've been up a creek (or more literally, lost in the middle of an unfamiliar city!) without it.

But the little battery pack I tote around is only really for emergencies—it can barely top off my iPhone when the phone is already at 50% capacity, and if the iPhone gets below 10%, it'll struggle to even maintain the current charge if I have to use the iPhone while charging!

Intocircuit Power Castle - Front

Controlling PWR and ACT LEDs on the Raspberry Pi

All Raspberry Pi models have a few built-in LEDs; the earlier models had PWR, ACT, and networking status LEDs all lined up on the board itself; for the B+ and model 2 B, the networking LEDs moved onto the network jack itself, leaving just two LEDs; PWR (a red LED) and ACT (a green LED).

Normally, whenever the Pi is powered on—except if the power supply dips below something like 4.5VDC—the red PWR LED remains lit no matter what. If you wanted to 'disable' the LED, you'd have to put a piece of tape or something else over the LED, or get out a soldering iron and modify the hardware a bit.

Raspberry Pi model 2 B, B+ and A+

Luckily, with the Pi 2 model B, B+, A+, and Zero, you can control the LEDs in software, in a few different ways. The simplest way to change the way these LEDs work is to modify the trigger for each LED by setting it in /sys/class/leds/led[LED_ID]/trigger, where you replace [LED_ID] with 0 for the green ACT LED, and 1 for the red PWR LED.

For example: