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.