HOW to Make a Track Alarm with Kidspico

Flow

Assembly

Required Parts

Place the pressure sensitive area of the sensor on a firm, flat surface when in use. For details, please refer to Chapter 3.6.

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Step 9

Completed

Wiring Diagram

Test Code

Open 4.3Track alarm.py in Files and click .

'''
 * Filename    : Smart Safe Home: Track Alarm
 * Thonny      : Thonny 4.1.4
 * Auther      : http//www.keyestudio.com
'''
from machine import Pin,ADC
import time
from HT16K33 import ht16k33

Pressure = ADC(28)  # thin film pressure sensor

scl = Pin(5) 
sda = Pin(4)
bus = 0

LedArray1 = [0,0,0,1,1,0,0,0,   # footprint
             1,1,0,1,1,0,1,1,
             1,1,0,0,0,0,1,1,
             0,0,0,1,1,0,0,0,
             0,0,1,1,1,1,0,0,
             0,1,1,1,1,1,1,0,
             0,1,1,1,1,1,1,0,
             0,0,1,1,1,1,0,0]

Triaxial = ht16k33(bus, scl, sda)

while True:
    Pressure_value = Pressure.read_u16()
    if Pressure_value < 40000:
        Triaxial.setRotation(0)  # rotation direction
        Triaxial.clear()
        for i in range(8):
            for j in range(8):
                Triaxial.drawPixel(i, j, LedArray1[i*8+j])
        Triaxial.writeDisplay()    
        time.sleep(1)
    else:
        Triaxial.clear()
        Triaxial.writeDisplay() 

Explanations

Conceive:

When someone steps on the pressure sensing area of the sensor, the output analog value of the sensor will decrease.

Set a threshold first to determine whether there is pressure. When the output value is smaller than the threshold, someone steps on this area; If the value is greater than the threshold, no track is detected.

If pressure is detected, a footprint icon will be displayed on the dot matrix.

Code structure:

1. Initialization.

   Configure I2C, set scl and sda pins, set the pin of the thin film pressure sensor.

   Create an 8*8 array LedArray1 to set the footprint icon.

2. Loop.

   Determine whether the output analog value is smaller than 40000 (if yes, tracks are detected).

   • analog value < 40000: the dot matrix shows a footprint icon as a reminder.

   • analog value ≥ 40000: the dot matrix displays nothing.

Test Result

After uploading code, press the thin film with your finger, and you will see the dot matrix shows a footprint.