Are you ever out shopping and forget if you are out of a your favourite food? If so, this project is for you.
This project creates a simple webserver that shows if you are low on a specific food or drink, for example, milk. It uses the linkit ONE microcontroller for the WiFi connection, and a small piece of Velostat, a force sensitive material. The board is able to detect the difference between a full milk jug and an empty one, using the pressure sensor.
Step 1: Parts and Tools
Here are the Parts and tools that you will need to make this project:
Linkit ONE board and WiFi antenna
10k ohm resistor
Computer with the latest version of the Arduino IDE
Soldering Iron and solder
Step 2: Wiring
Use the attached wiring diagram to make the required connections to the linkit ONE. The red LED is mainly used to make sure that the sensor is working properly and for calibration if you want to use a specific type of food or drink.
For the velostat, strip two wires so it has about an inch of exposed wire. Then, attach them to each side of the velostat using some tape.
Step 3: Code
Download the (First) attached code. Now, change the line that says "#define WIFI_AP "Your Network" " and change "Your Network" to the name of your wifi network. Do the same with the line of code after that, but change "Your Password" to the password to your wifi network. Now, upload it to the Linkit ONE. Open the serial monitor and copy the first IP address shown as you will need it later.
Now that you have the IP address, download the second code and do the same to the two lines of code, in fact, you can just copy/paste. Now, upload the code to the linkit ONE
Step 4: Test...
To test the device, place a (full) container of some sort, like a milk jug, onto the velostat sensor. The red LED will turn on if the food or drink is heavy enough. Now, you can type in the IP address into your web browser to see if it is triggered when the container is on the sensor.