Soil moisture sensor with message notification

from machine import ADC, Pin, Timer, UART
import utime
uart = UART(0,9600)
#ledplacuta
led_placuta = Pin(25, Pin.OUT)
timer = Timer()
def blink(timer):
    led_placuta.toggle()
    
#led pus de noi
led = Pin(14, Pin.OUT)

# use variables instead of numbers:
soil = ADC(Pin(26)) # Soil moisture PIN reference
#Calibraton values
min_moisture=0
max_moisture=45235

readDelay = 2 # delay between readings

send=UART(0,9600)
while True:
    message=''
    moisture = (min_moisture+soil.read_u16())*100/(max_moisture-min_moisture)
    message=str(moisture)
    print("moisture: " + "%.2f" % moisture +"% (adc: "+str(soil.read_u16())+")")
    if moisture < 1:
        print("Florile au nevoie de apa")
        message+="  u" 
        led.value(1)
    elif moisture > 70:
        print(" Florile au prea multa apa")
        message+=" s" 
        led.value(1)
    else:
        led.value(0)
    send.write(message)
    utime.sleep(readDelay) # set a delay between readings
    timer.init(freq=25, mode=Timer.PERIODIC, callback=blink)
led.value(0)