Back Awareness Response Transmitter I

This interactive device makes use of 2 Infrared sensors to detect presence of obstacles from behind, particularly useful in places where you may potentially block someone’s path (narrow paths, etc). It can also be used as a defensive too for early warning of someone sneaking up on you.

How it works:

1. Wearer will wear this like a belt.
2. Switch to switch on
3. If something is in the proximity of 1 of the sensor (eg. the left side), the left vibration module will start to vibrate
4. Depending on the proximity, the vibration varies. As the strength of the vibration cannot be controlled, I only controlled the frequency of vibration in relation to the proximity. The closer something is, the more frequent it vibrates. This is similar to car reversing system.
5. If the obstacle is in between both sensors, and both sensors pick up the obstacle, both will vibrate indicating the obstacle being in the middle. But the threshold for this is too low (I think) and as such it isn’t very sensitive.

Problems:

1. the vibration is very strong so it can be uncomfortable, and that cannot be controlled.
2. if the wearer is leaning against the wall, it will keep vibrating. To solve this, one can simply switch it off
3. Form not fitting, could be more flexible and concave rather than convex

Process

Template for the form

Putting it together into a half-sphere

Trying out the sensors

 

Putting the IR sensors on

Putting the switch and the battery pack together

The final form!!!

Code

Base system:

How the vibration module and IR sensor working together

This is some extra stuff I did to make the vibration not repeat itself if its within the same range for at least 1 cycle of the code. Doesn’t work well so I didn’t use it.

Documentation: