######  Import the Timer library, so we can use interrupt and callback functions - ING  ######
######  Timer instructions are here: Please read https://docs.micropython.org/en/latest/library/pyb.Timer.html
from machine import Timer

# Initialise the Red LED port, a toggle variable, and an instance of a "Timer".
ledRed = machine.Pin(21, machine.Pin.OUT)
toggleRed = False
redRate = Timer()
######  This is the RED interrupt routine.  Keep it short so that it can then jump back to the main loop.
def redLED_interrupt(redRate):
    global toggleRed
    toggleRed = True

######  Initialise the Green LED port, a toggle variable, and an instance of a "Timer".
ledGreen = machine.Pin(2, machine.Pin.OUT)
toggleGreen = False
greenRate = Timer()
######  This is the GREEN interrupt routine.  Keep it short so that it can then jump back to the main loop.
def greenLED_interrupt(greenRate):
    global toggleGreen
    toggleGreen = True

######  similarly, This is a fast clock interrupt routine,
fastClock = Timer()
counter1sec = 0
secondFlag = True
### using a flag called secondFlag to be asserted True every 1000 milliseconds.
def clockTicker_interrupt(fastClock):
    global counter1sec, secondFlag  
    if counter1sec > 1000:
        secondFlag = True
        counter1sec = 0
    else:
        counter1sec = counter1sec+1

###########  ACTION starts here! let's start the background timers, and wait in the while loop!  ###########
redRate.init(freq=3,mode=Timer.PERIODIC, callback=redLED_interrupt)
greenRate.init(freq=8,mode=Timer.PERIODIC, callback=greenLED_interrupt)
fastClock.init(freq=1000,mode=Timer.PERIODIC, callback=clockTicker_interrupt)

count = 0

while 1:
# We can now do multiple things in the forground!  AVOID using sleep delays

# Act on the Red led
    if toggleRed == True:
        ledRed.toggle()
        toggleRed = False

# Act on the Green led
    if toggleGreen == True:
        ledGreen.toggle()
        toggleGreen = False

# Act upon the 1 second rate stuff
    if secondFlag == True:
        if count == 5:
            count = 1
            print("\nlet's repeat:")
        else:
            count = count+1

        print("Count to 5...", count)
        secondFlag = False

######### Other routines in this forever loop can be added such as checking ADC inputs, updating OLED display, making tones, etc,
######### either using the existing timer flags, or create more!  ING #########