This is an early prototype of a water bottle that helps you to consume a healthy amount of water per day. It does so by indicating, with a LED, whether you drank enough water. The construction measures the amount of water in the bottle, with a pressure sensor and sends this data to an Arduino.
- Force Sensitive Resistor
- Arduino Uno
- Resistor 10KOhm x 2
- Red LED
- Green LED
- Yellow LED
Step1: Find a bottle
We used a 750ml bottle because our sensor could only measure weight up to 1kg
Step2: Build a housing
Since the pressure sensor we use was very sensitive to small movement of the bottle we build a housing for it to keep the whole construction stable. We used cardboard and lasercutter to make the housing. The svg file is provided but there is of course the possibility that you need to adjust the size to your bottle.
Step3: Wire the circuit
Wire the circuit as shown in the schematic image which is provided and tape the sensor inside the housing below the bottle.
Step4: Upload Arduino code
Upload the provided code to your arduino and you are good to go.
About the code:
The logic for the program is with checking multiple boolean values whether the bottle is full and is not empty and when its empty and filled again the bottle count is incremented by 1, hence if we could get the bottle count for the day to be 3 then we can get the green LED glowing.
Problems of the Construction:
The sensivity of the sensor is a huge problem. It outputs values with a high variance and is very sensitive to movement of the bottle (which is a problem since you are supposed to drink from it). We are open to any suggestions or other sensors which could be helpful in this project. We actually used the metal part of the plate of a kitchen scale (picture provided) because it was the best material to transport the pressure from the bottle to the sensor. We plugged this between the bottle and the sensor and build a small plate around it to apply the force evenly.