Build your own dumb USB power strip

diy-usb-power-strip

Here’s a USB charging center which [Kenneth Finnegan] built using parts from his junk bin. We’d like to reiterate our claim that he must have the most magical of junk bins (the last thing we saw him pull out of it was a 24-port managed Ethernet switch).

The jack on the side accepts the barrel connector from a 12V … Read the rest

Cracking open a 24-port switch so you don’t have to

hp-procurve-ethernet-switch-teardown

[Kenneth Finnegan's] post about this 24-Port HP ProCurve 2824 Ethernet Switch teardown was a delight to read. He’s taking an introduction to networking class at California Polytechnic State University. One of their labs included virtual machines shooting thousands of new MAC addresses at the thing all at once. Despite it’s ability to switch data at a blazing fast rate, it’s … Read the rest

555-timer charges lead acid batteries

555-timer-charges-lead-acid-batteries

[Kenneth Finnegan] took the focus of a great design and redirected it to solve his own problem. What results is this lead acid battery charger based on the 555 timer. It’s not a top-of-the-line, all the bells and whistles type of charger. But it gets the job done with a readily available IC and no need to code for … Read the rest

Dot matrix printer spits out any tweet mentioning @KWF

Earlier this month, [Kenneth] picked up an old dot matrix printer at the Silicon Valley Flea Market and subsequently found two cases of tractor feed printer paper. It’s a marriage made in heaven for a dot matrix twitter printer.

[Kenneth] used a BeagleBone - a tiny single board computer running Linux – to connect to the Internet and fetch … Read the rest

Video Review: STM32F0-Discovery board

The STM32 Discovery boards are nothing new, we’ve looked at them several times. But the newest sibling in the line might be just the thing to make the leap from your steadfast 8-bit projects. We got our hands on it and recorded a video review.

The STM32F0-Discovery gives you a programmer and ARM Cortex-M0 chip all on one convenient board. … Read the rest

Intro to Phase-Locked Loops

[Kenneth Finnegan] put up a lengthy primer on PLLs (Phase-Locked Loops). We really enjoyed his presentation (even the part where he panders to Rigol for a free scope… sign us up for one of those too). The concepts behind a PLL are not hard to understand, and [Kenneth] managed to come up with a handful of different demonstrations that really … Read the rest

Numitron tube tutorial

Nixies and VFDs are great displays, but when using them you’ve got to deal with some fairly high voltages, at least for the micro projects we see on Hack a Day. Luckily, there’s another ancient technology that can be driven at tiny voltages. [Kenneth] put up a great tutorial on Numitron tubes to show the Internet how to get … Read the rest