Category Archives: Uncategorized

Approximate Sine Waves (how approximate is that?!)


I just installed a UPS the other day (an older Back-UPS XS1300, pictured) and noticed on the back it’s an “approximate sine wave” output. After reading the bottom closer, it’s specified that the device, under 25% load, has a THD of 55% and a maximum harmonic amplitude of 43% of the fundamental’s amplitude. Sounds pretty bad, but what does that really look like? Continue reading

How to organize your SMD parts, cheap (also, heat-sealing with a soldering iron)

I’ve amassed a lot of loose surface mount parts and it finally came time to do something about organizing them – digging through piles of little plastic bags in a box gets real old real fast. I considered buying something like Adafruit’s SMD parts kit and just stuffing my extra parts in the corresponding slots, but I don’t currently have a pressing need for all the parts, and I came up with something a little cheaper. Perhaps more interesting, I’ve got a nice recipe for heat sealing plastic (like anti-static bags) with your soldering iron without messing it up. Continue reading

iPhone JailbreakMe 2.0 Testing


You probably don’t even care about any of this. If that’s true, ignore it. Testing results for

3G/4.0 – Untested, jailbroken with Pwnage Tool
3G/4.0.1 (UPDATED from above) – Failure, Safari crash to SpringBoard. Reboot spawns reboot loop.
Entered DFU mode to restore to fresh stock 4.0.1.
3G/4.0.1 (stock restored) – Great success! High five!
3GS/4.0.1 (fresh restore) – Great success! High five!
4/4.0.1 – Haven’t tried yet, waiting for MMS/FaceTime fix (since I actually use this phone) Great success! High five!  And MMS/FaceTime both work now too.

3G/3gS also unlocked with Ultrasn0w, 4 not yet (and I have no sim to test with anyway).

Tip For Quick Switching Simulator To Device

picture-3Here’s a quick tip I picked up via the Stanford CS193P iPhone Programming (coral) course. Normally, to switch between device and simulator debugging requires going to the Project > Set Active SDK menu. Since I switch between said active SDKs almost every other build at points, the whole menu thing gets annoying. Luckily, it’s easy to put this drop-down menu in your toolbar in Xcode. Continue reading