Category Archives: Technology

Pocket Preservation: Keyless Entry and a Silicone Sheath

I wear nice pants (often suit pants) to work, and had more than one suit have the pockets reach the end of their useful lives long before the suit was otherwise showing signs of wear. The culprit was my keys and keyring, which would also scratch other items in my pockets. I eliminated most keys by shifting to keyless entry where possible, using number pad locks on doors at home and using the keyless entry fob for my Prius. The one key I couldn’t easily eliminate was my office key.

A few winter breaks ago, I took on a project to address this. I decided to turn my office door handle into a capacitive touch sensor. I programmed an Arduino to sense the secret sequence of taps on the outer door handle. In response, a motor pulled down the inner door handle and thus unlocked the door. It worked perfectly, until I tried it with the door closed. I turns out my office’s metal door frame grounded the handle, so the capacitive touch “interface” of the door handle only worked when the door was open. While there were some fun possibilities to address this while still using the Arduino/motor approach, that winter break came to an end before I had time to try them.

In the interim, I found a solution which has been appealing enough that I’ve prioritized other projects over returning to the Arduino door handle. The interim solution was to buy a silicon cover for my one remaining key, preventing it from sawing into my pants or other pocket items.

I’d like to get away from carrying things altogether, so I may eventually invest in an after-market keyless entry number pad for my car and may return to the Arduino door handle project eventually.

Warning Lights on my 2008 Prius

We had a great trip visiting my aunt and uncle in the Poconos this weekend. On the way there, we had a bit of a misadventure because some warning lights on my car (2008 Prius) came on:


At the start of the trip, everything was fine. The car had recently received a new suspension and some other repairs. Twice since then, before this trip, the triangle light (above) turned on during hard breaking. This had been accompanied by the word “PROBLEM” on the car’s monitor, but both had only lasted as long as the breaks were being applied. This trip, things got more interesting. After about 70 miles, the triangle and the check engine lights came on. Those were later joined by the exclamation-point-in-parentheses and VSC lights. On the monitor, there was a persistent picture of a car with an exclamation point. Leaving the car off for a while and turning it back on, only the triangle and engine lights were on, but the other two came back after more driving.

We decided to stop at an Enterprise and rent a car to drive the remaining 170 miles. We did a one-way rental so that the rental could follow the Prius on the way back home the next day (Sunday). The Prius had similar issues on the return trip – it started with the two lights and it become four after a while. After about 50 miles, the car couldn’t maintain speed and started slowing down on the highway. I pulled over and turned off the car for a few minutes, after which it was able to drive again. We made it to the local Toyota service center near our home, so we will see what they say…

Pocket Computer

I wanted to be able to type at full speed using only items that fit in my pocket. As the weather got hot and humid this year, I tired of carrying my laptop bag to meetings. I also wanted to avoid the concern of losing my laptop bag. I’ve been trying out the following solution for a few weeks now and am loving it:

Pocket computer in action

I’ve used this in meetings, restaurants, and on the fold-out table of an airplane. It’s substantially faster than screen-based text entry and I always have it with me (vs. my laptop, which I often wouldn’t have on hand).

This setup consists of:

  • iClever (IC-BK06) folding bluetooth keyboard ($29.99)
    I wanted a keyboard with normal spacing which folded to a thin and small enough shape to fit into a pocket without being noticeable by myself or others. It fits perfectly in my suit jacket pocket and in my pants pocket. In my suit jacket pocket, I can’t even tell that it’s there. It charges via mini-USB and the charges seem to last forever. There are other keyboards out there, but none I found struck the same balance between portability and providing a full size experience. This keyboard does have a few tradeoffs – the number and punctuation keys are not full-sized (I’ve found this works just fine for me) and it benefits from a flat surface (the keyboard doesn’t lock into an open position). Those keyboards which solve those problems introduce others (e.g. the trifold keyboards I found which lock into an open position are thicker when folded), so the IC-BK06 seems to strike the best balance in making the necessarily compromises for portability.
  • Pocket Tripod ($28)
    The dimensions of a business card, it folds into a few configurations to allow a phone (plus a phone’s protective case) to stand and rotate to any angle you like. There are cheaper options available. At first, I just propped my phone against whatever was handy, or left it flat on the table. Ultimately, I wanted something which would give me a good viewing angle and store nicely with the credit and ID cards I keep in my pocket. Note that the slots in the Pocket Tripod (where the phone sits) need to be chosen to be the right size. The Pocket Tripod website has a list of which slot sizes are best for most phone/case combinations.
  • Evo Mesh Sport Case ($12.55) and an iPhone 6S
    This same setup would work with any phone and case. The Apple Store salesperson recommended the Evo Mesh case when I bought my phone as the most protective option, and it’s helped my phone survive an impressive number of drops. This case/phone combination wasn’t listed on the Pocket Tripod website, so I used calipers to measure the combined thickness of the phone and case. I measured just over 9mm so I ordered the Pocket Tripod with 9.0mm slots, which gave a perfect fit.
Pocket Tripod, iPhone 6S with Evo Mesh Sport case, iClever IC-BK06

Single Cable for Charging+Audio in the Car

I wanted a single cable to connect to my phone in the car for both charging and audio. This was for two reasons. First, I kept forgetting to charge my phone while driving. Second, bluetooth audio receivers kept failing me. Thus switching to a wired connection for audio – which also automatically meant my phone was charging – was the perfect solution.

I have an iPhone, so it needed to be a lightning cable. A few vendors now provide “charge and sync” splitters, but all the ones I found did the splitting very close to the phone. I did not want to deal with two wires running all the way to my phone, so instead combined the following.

  • Apple iPhone Lightning Dock ($44.31)
    These are the docks used to display iPhones in an Apple Store. They connect to the iPhone via lightning and provide both a lightning port (for charging) and audio out.
  • 6 foot DockXtender Lightning Extension Cable ($19.95)
    This lightning extension cable is long enough to reach from my phone (mounted next to my steering wheel) to the lightning dock (above), which I keep in the built-in storage bin between the front seats of my car. The end which connects to my phone is designed to fit most phone cases and works very well with my case.
  • 3.5mm audio cable ($4.99)
    Any male stereo audio cable would do. This connected the Dock to the aux in for my car (which happened to be inside the aforementioned built-in storage bin)
  • ProClip mount with adjustable holder ($69.98)
    Mounting the phone at eye level is helpful for navigation apps or for controlling music/audiobooks. This particular mount has worked very well for me. The upsides are (1) this attaches very firmly to the car, so any children, pets, etc., will not knock it out of place, and (2) the perfect fit means it’s very quick to slide my phone in and pull it out again. The downsides are (1) this is relatively pricey compared to other options and (2) my wife’s phone+case – a different size than my phone+case – doesn’t fit, so she can’t put her phone in this mount when she is driving my car.

I have been using this configuration for a year now (after many shorter-lived configurations without the dock, extender and mount) and this is by far the best setup I’ve tried. I expect I’ll stick with this for as long as my car will last.