How to Use Pico to Make Electronic hourglass --- RaspberryPiPico Kit

Elecrow · September 2022

Project Introduction:

Turn the encoder to set the time, and it will be displayed on the TM1637 4-Bits digital tube in real time. Press the button and the electronic hourglass starts working.

Material preparation:

Raspberry Pi Pico*1, USB Cable*1, Breadboard*1, Encoder*1, TM1637 4-Bits Digital Tube*1, Dupont line

Circuit connection:

Library file installation:

Upload the "tm1637.py" library file to the Raspberry Pi Pico.
Step1: Download tm1637.zip, unzip the file and copy tm1637.py to library folder.
Step2: Connect the Pico to Thonny with a USB cable;
Step3: Find the "tm1637.py" library in the file window;
Step4: Right-click and select "Upload to / " to start uploading the library file;
Step5: "tm1637.py" appears at bottom left, indicating that the upload is successful, and you can start running the program.

Program analysis: Electronic Hourglass


from machine import Pin
from time import sleep
import tm1637

tm = tm1637.TM1637(clk=Pin(4), dio=Pin(5))
RoA_Pin = 0               # CLK
RoB_Pin = 1               # DT
Btn_Pin = 2                # SW

globalCounter = 0          # counter value
flag = 0                   # Whether the rotation flag occurs
Last_RoB_Status = 0       # DT state
Current_RoB_Status = 0    # CLK state

def setup():
    global clk_RoA
    global dt_RoB
    global sw_BtN
    
    clk_RoA =  Pin(RoA_Pin,Pin.IN)           
    dt_RoB = Pin(RoB_Pin,Pin.IN)              
    sw_BtN = Pin(Btn_Pin,Pin.IN, Pin.PULL_UP) 
    # Initialize the interrupt function, when the SW pin is 0, the interrupt is enabled
    sw_BtN.irq(trigger=Pin.IRQ_FALLING,handler=btnISR)

# Rotation code direction bit judgment function
def rotaryDeal():
    global flag                   
    global Last_RoB_Status
    global Current_RoB_Status
    global globalCounter         

    Last_RoB_Status = dt_RoB.value()   
    # Judging the level change of the CLK pin to distinguish the direction
    while(not clk_RoA.value()):       
        Current_RoB_Status = dt_RoB.value() 
        flag = 1                    # Rotation mark occurs
    if flag == 1:                     # The flag bit is 1 and a rotation has occurred
        flag = 0                     # Reset flag bit
        if (Last_RoB_Status == 0) and (Current_RoB_Status == 1):
            globalCounter = globalCounter + 1    # counterclockwise, positive
        if (Last_RoB_Status == 1) and (Current_RoB_Status == 0):
            globalCounter = globalCounter - 1     # Clockwise, negative

# Interrupt function, when the SW pin is 0, the interrupt is enabled
def btnISR(chn):
    global globalCounter
    globalCounter = 0 
    print ('globalCounter = %d' %globalCounter)
    while True:
    # Define a counter that changes every 1 second
        tm.number(globalCounter)
        globalCounter = globalCounter - 1
        sleep(1)
        if globalCounter == 0:
            break

def loop():
    global globalCounter  
    tmp = 0   
    while True:
        rotaryDeal()      
        if etmp != globalCounter:
            print ('globalCounter = %d' % globalCounter)
            tmp = globalCounter    
            tm.number(globalCounter)
            
if __name__ == '__main__':    
    setup() 
    loop()

Click link below to watch video:

https://www.youtube.com/watch?v=Sl1dVGrHXFg