Category: General

So, yesterday the outdoors turned into this. Not quite the snowpocalypse, but it was enough that a travel ban was in effect, and work was closed. What happens when we’re stuck in the house with gadgets? All right, I’d like to tell you that’s the reason, but this actually got broken open accidentally at my…

My wife goes to bed long before me, so when I go to bed, it behooves me to do so without significant light or racket. After countless nights of fiddling with a 3-sided micro-USB cable in the dark, I bought this neat little USB phone charger. It’s not the cheapest, nor the priciest, but was…

So, I picked up a pair of these cheapo solar pump on fleabay for about 6 or 8 bucks a pop, to filter water for the fish in my old-lady-swallowed-a-fly lotus pot. They actually work pretty well, apart from one very occasionally getting stuck and needing a spin by hand to get going. But it’s…

Goal: Produce reasonable impedance-matched (usually 50-ohms) RF feedlines for hobby-grade radio PCBs. Rather than get a PhD in RF engineering for a one-off project, use an online calculator and some rules of thumb to get a “good enough” first prototype. Problem: Most RF boards and stripline calculators assume or drive toward 4-layer boards. In hobby…

I recently assembled a set of prototype boards for a particular project at my day job, and ran a math- and memory-intensive test loop to test them out. Two of the boards ran the code fine, but one crashed consistently in a bizarre way that suggested corruption or otherwise unreliability of the RAM contents. Since…

Goal: Use the EFM32 microcontroller’s External Bus Interface (EBI) to place a large external SRAM and work with data larger than the chip’s internal memory will allow. Support dynamic memory allocation via standard malloc()/calloc() calls probably present in whatever 3rd-party code-snarfed-from-the-internet you are trying to integrate. Solution: First off, ignore any notes about needing to…

So, I’ve been playing around with the Lulzbot we got at work. Inspired by emmett’s sweet planetary gear bearing design, I adapted the design to be not a bearing but a peristaltic pump. Like the original bearing design, the pump prints as a single piece – no assembly required! – with captive rollers and no…

So… That day I never thought would come, and a younger me once *hoped* would never come…has come! Our first spawn, Max Charles G, was born 7/26/2014 at around 6:40am. Glad that’s over! I kid, but seriously, the hospital part is the only real sucky part (for us, at least – Max is pretty chill).…

Problem: When trying to delete or rename a folder, typically on a network drive, Windows 7 reports the action can’t be performed because a file is in use, even when you definitely don’t have any files open in that folder (or even have a subfolder displayed in another Explorer window), and haven’t for quite some…

Here is a tiny little python script to generate file system fragmentation. “But Tiiiiiiim! Tools are supposed to defragment your filesystem! Why would you ever want a script to fragment one?” In one of the gadgets I’m working on, I had a need to evaluate disk (well, memory card) performance in real-world and worst-case scenarios.…

Very common need: Copy some data into an Excel cell from an arbitrary other source (including another Excel sheet, or webpage, etc.). In the process, strip any external formatting, HTML tables, etc. with extreme vengeance and only paste the plain text. Traditional way: Mouse fandango (Excel 2013: Home -> Paste -> Paste Special…->Text->OK) for every…

The EFM32 SWO port operates from a 14MHz timebase regardless of the current CPU frequency. Autodetection of actual frequency is feasible, but irrelevant. Manually specify 14MHz for “CPUFreq” in SWO Viewer. The corresponding calculated SWOFreq should be 900KHz. Tested and working as of SWOViewer version 4.84f.

Problem 1) TortoisePlink.exe crashes when attempting CVS operations. Win7 throws the error message “A problem caused this program to stop working correctly” (gee, thanks, that’s a most helpful crash dump) and checks The Interclouds for solutions (finding none). Groveling down to the actual crash report (Control Panel -> Administrative Tools -> Event Viewer -> Windows…

My brother-in-law and I put this together over a long afternoon. Much of that time was spent building and leveling a 4×4 frame – the actual construction went pretty smoothly. On the other hand… It stayed intact for about 24 hours. The very next day, a typical springtime storm rolled through with a bit of…

First note to myself: NEVER USE MICROCHIP AGAIN. If I didn’t just need to make “a couple tiny updates” to an already selling, on-the-shelf project I’d just scrap the PIC18 for an EFM32TGxxx part, gcc (shaft of light from the sky, harps playing melodically) and be done with this entire shit-show. Insert whining about the…

Ha ha, apparently proselytizing about the “Internet of Things” is trendy again. Don’t hold your breath kids; until IPv6 is a thing that’s really a thing, enjoy your “small home network of things”, where your game console, thermostat and toaster have 192.168.x.x IP addresses dangling from your cablemodem, and require a 3rd-party cloud service to…

My day-job employer makes fancy piezoelectric actuators. Not long ago I was asked out of the blue: “Hey, the Haptics Symposium is in less than 2 weeks… It’s in Houston, TX. Want to go?” “*looks out window at yet more falling snow* Hell yeah.” “Oh yeah, and we’re going to need some demos so…” Of…

So, I just discovered I’m completely out of Pumpkin Fail (euphemistically, Cinnamon Cream Ale – that I only too late realized I forgot to add the pumpkin to the boil…yeah, don’t ask.). Time for a new brew! Haven’t decided what to make yet, but at least I know just what to call it… (With apologies…