I am building a device to remind myself of keeping my spine straight.
I have a way to implement the "reminder" feature and the control package, but I have not found a way to measure changes in curvature in a small form factor.
I thought about using a simple light encoder with a marked rod that slides through it, but that would make it much too large to stay hidden under clothes. Rotary encoders suffer from the same problem. Plus, to get a reliable value, I would need multiple individual sensors.
One way I can think of is using something similar to this and monitoring changes in pressure in the different tubes, but this seems unviable to me.
A perfect solution would be something directly implemented in the flexible surface... Some sort of flexible PCB based solution perhaps.
How can I detect changes in curvature?