My company requires us to lock our computers anytime we step away. This is easy enough to do in Windows by pressing Win+L, but that isn’t the slack way. In addition sometimes you have already stood up, taken your hands away from the keyboard when you remember you need to lock the computer. So I decided to implement the BRB BRB (Be Right Back Big Red Button). This gives me a nice large button to push that locks my computer. It has the side benefit of just being fun to mash on.
Following is a quick run down of the parts and software. This is not a step by step build, though I may do one in the future as this is a simple and rewarding projects for someone of any skill level.
This is really a simple project you need the following (with estimated costs):
Assembly is pretty easy. You need 2 short (about 2″) pieces of wire. Strip and tin each end and hook one to the Teensy GND connection, and the other to the Teensy B0 connection. Almost any pin could be used, but B0 had the convenience of being right next to the GND connection.
The E-stop button I used was normally closed (NC), but the software will work with a normally open (NO) switch with an easy change. There are only two contacts on the switch so connect one of the two wires to each contact. It doesn’t matter which is which. If you have both NO, and NC contacts just pick which set you want and make sure the software is configured appropriately.
Also, most E-stop buttons latches in the “stop” position when pressed. The one I purchased was no exception. It required a slight turn to get it to release. This was not the behavior I wanted, so I disassembled the button mechanics and was able to easily disable the latch mechanism in a way it could easily be reversed. The specific procedure required will depend on the specific E-stop that you have.
I drilled a small notch at the top of the black bottom piece to allow the USB cable to escape.
I then attached the USB cable, gently fit the component in and closed up the case.
I used the Arduino environment and the Teensyduino libraries to program the Teensy. The same code could be used with minor modification if you want to use an Arduino Micro instead of the Teensy. The Adafruit Trinket may be an even better choice for this project for both size and cost.