flow sensor inconsistent wake up on occasional deepsleep mode use

[atugrulokur]

That code normally do this; it stay at deepsleep mode until it detected water flow after that wake up and start counting liter when water flow stoped it write the final value to new line at data.tx and go to deep sleep again. But sometimes it is wakes up read 0 write 0 LT/min to data.txt and go to deepsleep after and after. sometime it works as it should. it is confusing. Can you help me find where the problem is?
`from machine import Pin, ADC, deepsleep, RTC
import time
import esp32
import machine
from time import sleep

if machine.reset_cause() == machine.DEEPSLEEP_RESET:
print('woke up from a deep sleep')
rtc = RTC(

year, month, day, _weekday, hours, minutes, seconds, subseconds = rtc.datetime()
print(hours)
print(minutes)
print(day)
print(month)
print(year)

push_button = Pin(14, mode = Pin.IN) #setting push_button as wake up source
esp32.wake_on_ext0(pin = push_button, level = esp32.WAKEUP_ANY_HIGH) #initializing wake up

flow_sensor_pin = ADC(Pin(36))

calibration_factor = 7.5

flow_count = 0

flow_rate = 0

total_mililiter = 0

previous_millis = time.ticks_ms()

def flow_sensor_callback(p):
global flow_count
flow_count += 1

flow_sensor = Pin(36, Pin.IN)
flow_sensor.irq(trigger = Pin.IRQ_RISING, handler = flow_sensor_callback)

if flow_count <= 0 :
sleep(1)

while True:
current_millis = time.ticks_ms()
if flow_count > 0 : # Check if flow_count has been updated
if time.ticks_diff(current_millis, previous_millis) >= 1000:
flow_rate = (flow_count * calibration_factor) / (time.ticks_diff(current_millis, previous_millis))
total_mililiter += flow_rate

        print("flow rate L/sn:", flow_rate)
        print("total flow L/dk:", total_mililiter)
        
        flow_count = 0
        previous_millis = current_millis            
        sleep(0.1)
else:       
    
    print("Waiting for flow input...")        
    time.sleep(2)
    total_mililiter = 0
    machine.deepsleep()

`

[davefes]

First re-format your code.

<```py>
your code
<`>
I would throw a few print statements around and save your result to a file on flash ... that you could go back to and review.

What is `flow_sensor_pin = ADC(Pin(36))' doing? Are you trying to take an ADC reading?

[atugrulokur]

Sorry about that that is my my first discussion entry. I connected a bridge from flow sensor's signal cable to GPIO36, when detect HIGH signal, esp32 wakes up. but whether I connect or not that bridge it did that.

<```py>
from machine import Pin,  ADC, deepsleep, RTC
import time
import esp32
import machine
from time import sleep

if machine.reset_cause() == machine.DEEPSLEEP_RESET:
    print('woke up from a deep sleep')
rtc = RTC()

year, month, day, _weekday, hours, minutes, seconds, subseconds = rtc.datetime()
print(hours)
print(minutes)
print(day)
print(month)
print(year)

push_button = Pin(14, mode = Pin.IN)     #setting push_button as wake up source
esp32.wake_on_ext0(pin = push_button, level = esp32.WAKEUP_ANY_HIGH)  #initializing wake up



flow_sensor_pin = ADC(Pin(36))

calibration_factor = 7.5

flow_count = 0

flow_rate = 0

total_mililiter = 0

previous_millis = time.ticks_ms()


def flow_sensor_callback(p):
    global flow_count
    flow_count += 1
   
    
flow_sensor = Pin(36, Pin.IN)
flow_sensor.irq(trigger = Pin.IRQ_RISING, handler = flow_sensor_callback)

if flow_count <= 0 :
    sleep(1)

while True:
    current_millis = time.ticks_ms()
    if flow_count > 0 : # Check if flow_count has been updated
        if time.ticks_diff(current_millis, previous_millis) >= 1000:
            flow_rate = (flow_count * calibration_factor) / (time.ticks_diff(current_millis, previous_millis))        
            total_mililiter += flow_rate
           
            print("flow rate L/sn:", flow_rate)
            print("total flow L/dk:", total_mililiter)
            
            flow_count = 0
            previous_millis = current_millis            
            sleep(0.1)
    else:       
        
        print("Waiting for flow input...")        
        time.sleep(2)
        total_mililiter = 0
        machine.deepsleep()
<`>

[karfas]

Ideas to try:

• remove the unused flow_sensor_pin = ADC(Pin(36)) line. It's confusing and references to the same pin as the pulse counter, which may or may not have an effect.
• I don't see any reference to Pin(36) as wakeup source.
• Wakeup is most likely caused by the push_button pin, as there is no other wakeup source configured (check if the thing wakes up without this definition).
• Add pull down resistors (try the internal pull down via configuration. If this doesn't work, add an external 1k resistor).

I don't know how this can work, so I assume the source you posted is incomplete.

Also note that the ESP32 will need 1-2 seconds to boot from deepsleep. Pulses coming in during this time will be lost.

Edit: Even when Pin(36) is a wakeup source, you aren't counting this initial pulse.

[davefes]

The code formatting suggestion wasn't helpful. Ignore the <> around the characters, so at the beginning 3 backticks with py and then 3 backticks at the end. It is not likely to be a formatting error but it makes it easier for other people to read when one can see the indentations, etc.

Good luck.