“A motion-activated raffle device that can draw numbers or names. Users can specify the range of numbers or the list of names through WiFi.
n class, I use to raffle the names of students and the “lucky ones” get to answer an assignment or quiz on the board. I usually just ask them to write their names on a small piece of paper or use a software on my computer. One day it dawned on me: what if I create a device that raffle the names by shaking it?
The device is powered by a WeMos D1 Mini and an MPU6050 IMU. I could have just used a vibration sensor to detect motion but I found it too sensitive. With the MPU6050, I could adjust the “shake sensitivity” and maybe, in the future, make the device respond to shakes in different directions.
Choosing the WeMos D1 Mini stemmed from the fact that I don’t want the names or numbers to be hard coded. The names or numbers to be drawn should be entered by the user without having to change the code. So, I created a simple web interface that a user can access if he or she is connected to the WeMos D1’s access point. The names or numbers are then stored in the microcontroller’s EEPROM.
I know that EEPROM size is limited so the number of names that can be stored is small (4096 bytes so around 4096 letters). I plan to add an SD card slot in the future.”