Door alarm using microbit and python.
Using the microbit’s magnetometer to sound an alarm when the front door is open. The microbit sender will send a signal to receiver microbit in another part of the room to sound an alarm when the door is open. Signals are send using microbit’s Bluetooth.
Project Components Used: • 3 microbits • 2 battery packs • Blu tak • Breadboard • Buzzer • Neodymium magnet • Jumper wires • Microbit expansion board • Old Cell Phone Case • Keyestudio Micro bit Sensor V2 Shield • Red LED module
Supplemental Activities: Magnetic Reading for magnet:
Magnetic Reading Distance Magnetic Force Strength no magnet 59.98 microtesla 0 mm 2301.96 microtesla 1 mm 1830.34 microtesla 2 mm 1769.75 microtesla magnetic force strength is the average of 3 readings taken
ALGORITHM FOR CODING: Sender: Connect to channel 7 Read magnetic force If door is open (magStrength is less than 1750 microteslas) Send number 1 to Receiver Show check mark symbol Else (door is close) send number 2 to receiver show symbol ‘x’
Receiver: Connect to channel 7 Check for signal If receivedNumber is 1 Then show angry face Play loud sound If button A is pressed Stop all sound If receivedNumber is 2 Then show check mark symbol Stop loud sound Keep checking packet signal strength If strength is less than 0 Play loud sound If button press B is pressed Stop sound LED Receiver 2: Connect to channel 7 Check for signal If receivedNumber is 3 Turn on Red LED for 1 ms Turn off Red LED for 1 ms