They say that necessity is the “Mother of Invention”, but over the years we’ve started to suspect that her cousin might be an underutilized microcontroller. How else can you explain projects like the latest from [MN Maker], which takes the relatively simple concept of a contact lens holder and manages to turn it into an Internet-connected electronic appliance? Not that we’re complaining, of course.
He started out with a simple 3D printed holder for his wall that would let him pull out his daily lenses, which worked well enough and gained some popularity on Thingiverse. But he wondered if there wasn’t some way he could use a servo to automate the process. While he was at it, he might as well play with some of the components he’s been meaning to get some hands-on experience with, such as those little OLED displays all the cool kids are using.
Modifying his original design to incorporate servos in the bottom, he added a central compartment that would house an ESP8266 and a simple proximity sensor made from an IR LED and photodiode. The sensor tends to be a little twitchy, so he left a potentiometer inside the device so he can fine tune it as needed.
Strictly speaking the OLED display isn’t actually required for this project, but since he had a WiFi capable microcontroller sitting there doing basically nothing all day anyway, he added in a feature that shows the weather forecast. It’s not much of a stretch to say that the first thing you’d want to see in the morning after regaining the sense of sight is a readout of what the day’s weather will be, so we think it’s a fairly logical extension of the core functionality. Bonus points if he eventually adds in a notification to remind him it’s time to order more lenses when the dispenser starts getting low.
If you don’t have any contact lenses you need dispensed, never fear. A similar concept can be used to fire off your customized swag at hacker events. Don’t have any of that either? Well in that case you can always build a candy dispenser for Halloween.