This instructable will show you how to use pressure sensors for showing pressure difference in your Bra.

A lot of women have problems with finding the right bra size and end up with wearing the wrong one. This Instructable shows the beginning steps of how this could be changed by just putting pressure sensors in a bra which measure the pressure deviation within your bra and on your straps to see if the bra is the right fit for you.

Step 1: Step 1: What You Need

To do this, you need ofcourse a bra in which you could put these sensors.

besides that you need the following parts:

1. Arduino board

2. a Breadboard

3. 2 330 ohm resistors

4. 2 10 K resistors

5. 2 LED's

6. A textile analoge pressure sensor or 2 separate pressure sensors

Step 2: Step 2: the Curcuit Board

The image shows how you should build your circuit board for this pressure mapping.

In the image we made use of textile pressure sensors, you could of course also use different pressure sensors for testing this.

Connect the two Red LED ( or use two different LED's, as we did) to the digital ports 8 and 9 and use the 330 Ohm resistors in this loop. For the pressure sensors, use the 10K resistors in this loop and connect them to the Analog ports A0 and A1.

By pressing the sensors ( or first one) there will be an signal sended to the circuit board, which sends and signal out that makes the lights turn on.

Step 3: Step 3: the Code

The code used for these project is shown in the images above.

Step 4: Step 4: Testing It

We first started with testing only one light. By writing the code in such a way, we were able to show the change in light intensity when pressing the sensor.

After this, we started of doing the same for two sensors. During the first state testing there were some complications. The first test we did, showed the two lights lighting up when only one pressure sensor was used. By changing the code ( as shown in step tree) we were able to let them measure these different pressures for the different sensors. With the first test, it was able to turn on and off for the different sensors.

Step 5: Step 5: Testing in a Bra

After testing our circuit , we wanted to see if it would work. We made sure that the sensors were connected to longer wires to make it possible to put the sensors inside the bra.

By putting the bra with the sensors on the mannequin, and making one strap shorter ( putting more pressure on it) we could see the lights turning on.

Step 6: Step 6: Final Idea for FitBra

The final idea for this FitBra is that there will be multiple sensors added in the bra to measure the pressure all over the bra. By this it would be possible to measure the pressure deviation and see if this is just the wrong size for a person or if they should just loosen their straps a little bit.

By putting it in different bra sizes , people can already check inside the store if they have picked the right one.

The way we build it right now , should be changed a little. As mentioned before, textile pressure sensors would be more useful for building this and gives the opportunity to fit it all over the bra fabric. In stead if single LED's, an LED strip could be used showing where the pressure is to high. By coding it in such a way that the LED's change in color ( red, yellow, green) they could show where the pressure is to high. A way to make this possible within a bra, is by making a wireless connection so that it can be charged wirelessly.