We all know that drinking more water is good for our health, but it seems that increasing our daily water intake is always easier said than done. We fill up a bottle when we get into the office, then we throw ourselves into work. Few hours later, it still sits there, barely touched, on the left side of our desk. So, I thought why not make a device to remind people to drink water frequently throughout the day. Thus, here comes the idea of smart cup mat! The smart cup mat is mainly based on DFRobot Thin Film Pressure Sensor(SEN0294).

Design Idea: stick the flex sensor on the surface where the cup and the cup mat are in contact with each other. When the sensor detects that the pressure from the cup has been applying to the sensing area for over 1.5 hours, which also means the cup has not been touched in 1.5 hours, the buzzer starts making sound and the LED lights up. If the cup is picked off the cup mat for 3 seconds and above, the smart mat will decide you are drinking water now, and then it will restart timing.

To begin with, I want to introduce this flex pressure sensor. DFRobot is launching 7 new flex sensors with different sensing areas, covering three kinds of shape: circle, square, and long strip. These flex sensors feature great flexibility and easy to use, peel off the protection cover and stick the sensor on the surface you want to detect, then it works.

Here, I choose flex sensor of this kind (SEN0294):

Things you may need in the project:

1.RP-C18.3-ST Thin Film Pressure Sensor
2.Beetle - The Smallest Arduino
3.LED ×1
4.10k Resistor ×1
5.6.5*6.5mm smd buzzer  ×2
6.20cm Enameled wire 

Operation: 
Step 1: Build the model with 3D printer.

Step 2: Place and solder all parts onto the cup mat.

Step 3: cover the naked wires with Electrical Tape:

Step 4: burn the programs into beetle controller;

Here is the smart cup mat, give it a try if you like it!