After several dismissive attempts (3) -- we have haphazardly weaved together an Arduino Uno with cardboard, ultrasonic sensor, servo(s) and stepper(s) to remind, pester and intolerate your posture.
This project was hobbled together as a slight against the current incarnation of the maker community that at one time had been invested in improving humanity -- now succumbed to vanity and novelty. This project demonstrates that even with little to nothing applied, useless can harbor solution. Plaguing social venues with the antithesis breeds a consequence of evolutionary latency.
1. Arduino Uno
2. Stepper Motor (28BYJ-48)
3. Stepper Driver (ULN2003)
4. Ultrasonic Sensor (HC-SR04)
5. (2) Servos (High Torque)
1. 28BYJ-48 are cheap bcz they are in fact, rubbish -- do not be fooled by reviews documenting "high torque" and "power" bcz they fail to mention they only used these stepper motors to propel insignificantly sized wheeled robots a few paces before over heating and seizing.
2. Per my review above (Notation 1) may I suggest the alternative of either the purchase of or the modification of a servo to operate at 360 degree rotation -- ref. /redirect?event=desc&q=http%3A%2F%2Ftvmiller.com%2Findex.php%3Fentry%3Dentry160123-071155&redir_token=m2e0WSN2klRd1PyjZCZX16tfA6Z8MTUwNTM3MzQzMEAxNTA1Mjg3MDMw
3. A modified version of this code applied distance reference to alter the position of the shoulder servo relative to the actual distance of the sloucher -- due to impatience, disinterest and coherence of my typical distance, the code is commented but easily accessible.