Category: Technical Articles

August 12, 2010 / / Electronics
Bulbdial clock with breadboard and multimeter
Let’s make it touch sensitive!

UPDATE: People keep asking about the breadboard setup. Fair enough. I’ll throw together a quick overview when I get home today.
UPDATE: here it is: http://www.alexwhittemore.com/?p=462

The Bulbdial clock from Evil Mad Scientist is probably the coolest clock idea I’ve ever seen. Even cooler are my parents, who got the kit for my birthday.  The basic idea is that three rings of LEDs cast shadows onto a clock face to form H/M/S hands, somewhat like a sundial, with the hands slowly animating around. A lot of thought clearly went into making this kit, and it’s very nicely done, but there’s a major drawback: I want to use it on my bed side table, where I usually keep a clock, but it’s too bright for me to fall asleep! Of course, that’s been thought of too: in the normal view mode, the three buttons at the bottom of the clock are brightness up, down, and “mute,” which turns off the LEDs entirely. But they’re hard to get to buried underneath the frame of the clock, and it makes muting the display cumbersome in the dark. Let’s fix that!

August 11, 2010 / / Electronics
Crappy Buds
Crappy Buds

Say what you will, but iPhones are pretty awesome, and so are the headsets that come with them. At least up until you put them in your ears. The inline controls are awesome, but the speakers are uncomfortable, lacking in low end punch, and do nothing for sound isolation. Other, much better headphones exist, but for under a gajillion dollars, none come with the same kind of inline controls. Here’s how to have the best of both worlds.

August 7, 2010 / / Coding
August 4, 2010 / / Coding
Jailbreak Development for iOS4!

Vital Stats:
iOS 4.0.1
Xcode 3.2.3
Mac OSX 10.6.4 Snow Leopard
iPhones 3G, 3GS, 4 (I finally have the whole lineup!)

PROBLEM: I still can’t get iPhone 4 working. If you have one, please try it and help me out! UPDATE: Found the cause of the problem to be certain status bar libraries installed alongside other apps. I’m not sure why they cause the problem, but see full notes at the bottom of the post.

The Goal: As usual, we want to be able to click “build and go” in Xcode and get the app we’re working on to load to the phone and start up. Also, we want to be able to debug from within Xcode itself. After all, Xcode is cool, and terminal+makefiles+gcc+gdb is lame.

August 1, 2010 / / Electronics
LaunchPad
Meet the LaunchPad

I’ve been playing with the TI LaunchPad the last day or two since I’ve been home in the US. I ordered two when they launched, but I was abroad and only just started playing with them, and I have some first impressions to share.

January 11, 2010 / / iPhone
Debugging on device. Freaking finally.
Debugging on device. Freaking finally.

UPDATE: There’s a new method for iOS4 but they’re pretty similar anyway.

So it’s been a while, but now that I’m on break again and have some time, I’m doing a bit of iPhone development again. That means I’m going to need to debug on-device (or at least load my app to it to have fun in the real world with my handiwork). This time, the procedure’s a little different though.

Vital stats:
iPhone OS 3.1.2
Xcode version 3.2.1, 64 bit
Mac OSX 10.6.2 Snow Leopard

Let’s do it.

UPDATE: Corrected a problem with the run script build phase: corrected the directory names for the new version and copied the new phase that doesn’t include “resource_rules.plist.”

UPDATE 2: Somehow I forgot the add an identity step. It’s now #1 below. Sorry guys. Also, while this whole thing should apply to iPhoneOS 4, I’m going to officially text it/repost with 4.01 soon.

ARG! It's stuck!
ARG! It’s stuck!

So maybe this is the dumbest, easiest thing in the world and I’m the only one who didn’t know, but when I upgraded to the iPhone OS 3.0 SDK, I couldn’t for the life of me get the simulator to launch in ACTUAL OS 3.0 mode. You can change the version on the fly with the Hardware>Version menu, but every time I reran my app from Xcode, it’d revert back to 2.2.1. This finally became a problem when I needed to test an app with features unique to 3.0. Luckily, the fix isn’t all that hard.

July 18, 2009 / / Electronics
Yay bench power!
Yay bench power!

WARNING WARNING WARNING! Switching power supplies have many BACs (beefy-ass capacitors) that can hold lots of juice long after you’ve unplugged the unit. Do not crack one open like I did without knowing what you’re doing, it could seriously injure you or at least be really uncomfortable when you shock the crud out of yourself. I’m not responsible if you do just that, don’t say I didn’t warn you. I have a cable I made with a brush at the end that grounds everything it touches, I use it to brush the back of all power electronics before I work on them. You should too.

This is a pretty common one, but I like to add flair. I needed a bench power supply. Sadly, bench power supplies are very expensive, and I’m a poor college student. What I do have are computers. Lots of computers. In fact, I just brought to the recyclers about 100lbs of computer waste from machines that are too slow for even my standards. Luckily, one thing computers have going for them is very refined, VERY powerful power supplies.