Instructables member AGBarber has created a fantastic measuring tool in the form of a Arduino powered digital tape measure called the DMW. Which cannot only measure distances on surfaces but can also be used to calculate the diameter of pipes and features a useful tachometer. Check out the video below to learn more about the project and how you can easily create your very own using the instructions provided and a custom PCB board together with code which is downloadable from GitHub.
The DMW is powered by a rechargeable LiPo battery and AGBarber has kindly published all the files for the 3D printed parts, PCB and code to Github allowing you to build your very own with full instructions provided on the Instructables website.
This is great because it lets you measure in ways that would be tricky or impossible with a normal measuring tape. You can easily measure along curves, around corners, etc. Likewise, since you don’t have to deal with a physical tape, you aren’t really limited by length.
The upper limit on the DMW is 9999.99cm (your average tape measure will do 25ft, or 762cm), which is only due to the screen size limits. At the same time, its minimum measurement is just about 1mm (0.04in), making it more than accurate enough to be useful. You can also instantly convert from cm to inches, displayed as both in decimal form, and rounded to the nearest 1/16″ of an inch (configurable in the code).”
Arduino digital tape measure
“The brains of the DMW is an common Arduino Pro-Mini, which monitors the buttons, rotary sensor, and battery, while recording and displaying measurements on the DMW’s OLED screen. All the electronics are mounted on a single custom designed PCB, which is in-turn mounted in a 3D printed case. Overall, the DMW is almost the same size as a regular measuring tape, keeping it portable and easy to handle.
I’ve tried to keep the PCB fairly easy to assemble even if you’re newish to soldering. It’s mostly through-hole parts, with the exception of a few 0805 SMD sized resistors (should still be easy to solder). Likewise, I tried to use mainly common, off-the-shelf components that you should be able to easily find on Amazon, Aliexpress, Ebay, etc.”
Source: Awesome DIY Arduino digital tape measure
