I am starting to gather information for a project I am excited about; my project is essentially a barbell that can detect the weight loaded on it. I will quickly summarize the function and restraints. So normally the barbel is made of stainless steel and has two areas where you can load the weight, each side can hold about 7 plates without bending or warping so about 630lbs of safe load.
What I am trying to do is be able to detect the weight placed on both of the loading areas but I'm unsure of an elegant way to do this.
It has been proposed pressure sensors but I don't see this as elegant as it potentially could be. This is where I need your help; My question is - what sensors are able to detect weight in a robust reliable way that would make sense for my project?
Specifications/ info of embedded system: A men's Olympic bar is a metal bar that is 2.2 metres (7.2 ft) long and weighs 20 kilograms (44 lb). The outer ends are 50 millimetres (2.0 in) in diameter, while the grip section is 28 millimetres (1.1 in) in diameter, and 1.31 metres (4.3 ft) in length.
Electronics involved: stm32** chip with Bluetooth and accelerometers.
- able to detect weight from 5 lbs - 315 lbs
- robust and easy calibration cycle
- will not interfere with the loading of weights and de-loading process ( bar must be able to fit inside an Olympic barbell)
What we have tried As mentioned we have brainstormed a few ways to potentially embed this but most of our ideas involve a spring system. Although we have been exploring a fiber optic strain system but are unable to dig up info on this or how we could implement one or even if it would be reliable in our project.