def Test_DownUp():
    #by D@CC on 2023LDec17
    #using gpiozero, time
    #aux: Cytron MAKER pHAT
    #Output:
    #  watching GPIO: 21
    #  udud
    #  ^C: vTrig: [1702871616.7199683, 4.637, -4.659, 5.146, -5.162]
    progName="Test_DownUp"
    print(progName)
    pin=21  #GPIO 21 is phys.pin 40
    
    print("records switch triggers on GPIO:",pin)
    print("switch is a wire from phy pin 39 to 40")
    print("u means 'up +',d means 'down -'")
    print("Hit ^C to list their timed (sec.) vector.")

    global vTrig
    global isTrig
    
    isTrig=False    #until initialized
    #gpiozero import etc must accompany the try/except
    from gpiozero import Button
    button=Button(pin,pull_up=True)
    button.when_pressed =nTrig
    button.when_released =pTrig
    iTrig()
    isTrig=True   #enable trigger tracking
    if isTrig:
        print("watching GPIO:",pin)
    else:
        print("NOT watching GPIO:",pin)        
    #if end
    try:
        while True:
            # tight loop to monitor the pin
            pass
        #while end
    except:
        print()
        #print("except")
        prntTrig(vTrig)
    #def end
    #while end
#def end Test_Trig()
def prntTrig(vTrig):
    cntTrig=len(vTrig)
    print("^C: cntTrig:",cntTrig)
    print("vTrig:",vTrig)
    return
#def end prntTrig(vTrig)
def iTrig():
    # The following gpiozero import must accompany the try/except.
    #from gpiozero import LED, Button
    #from signal import pause   (not needed)
    import time
    global vTrig
    #initialize the vector vTrig
    dT=time.time()
    vTrig=[dT]
    #vTrig.append()
    #if end
    return
#def end
def nTrig():
    import time
    global vTrig
    global isTrig
    if isTrig:
    #if True:
        minusOne=-1
        dT=(time.time()-vTrig[0])*1000
        dT=minusOne*(int(dT)/1000.)
        vTrig.append(dT)
        print("d",end='')
#def end nTrig
def pTrig():
    import time
    global vTrig
    global isTrig
    if isTrig:
    #if True :
        dT=(time.time()-vTrig[0])*1000
        dT=int(dT)/1000.
        vTrig.append(dT)
        print("u",end='')
#def end pTrig
if __name__=="__main__":
    Test_DownUp()
#if end
#/Test_DownUp.py