Project Energy 32: Read analog water meter or analog gas meter pulses using inductive sensors, export water and gas usage using MQTT.
The water sensor component uses a digital proximity sensor (LJ12A3-4-Z/BX) that detects metallic proximity over a distance of at most 4mm.
The gas sensor component uses an analog hall sensor (SS49E) that ...
... alternatives at e.g. https://github.com/gizmocuz/esp_proximity_sensor_mqtt
Fewer syscalls, more waiting (see below).
Fix images/setup/howto here.
Detect MQTT send misconfiguration? Right now we saw multiple pushes being stuck (multiple tasks hanging at mqtt publish?).
Fewer syscalls
The basis for this is the following code. Ideally we'd like to do fewer syscalls (longer epoll_wait) than we do now. For another day.
.. code-block:: python
import time
import RPi.GPIO as GPIO
from datetime import datetime
GPIO6 = 22
def main():
# Aqua-pin:
PIN_AQUA = GPIO6
print(GPIO.RPI_INFO)
GPIO.setwarnings(True)
GPIO.setmode(GPIO.BOARD)
GPIO.setup(PIN_AQUA, GPIO.IN)
current = GPIO.input(PIN_AQUA)
long_timeout_ms = 5000
short_timeout_ms = 100
t0 = time.time()
liters = 0
while True:
if current == GPIO.LOW:
if GPIO.wait_for_edge(PIN_AQUA, GPIO.RISING, timeout=long_timeout_ms) is None:
#print('we are LOW, no change')
continue
if GPIO.wait_for_edge(PIN_AQUA, GPIO.FALLING, timeout=short_timeout_ms) is not None:
print(datetime.now(), 'we saw LOW->HIGH->LOW change, ignoring')
continue
current = GPIO.HIGH
#print('we re now HIGH')
else:
if GPIO.wait_for_edge(PIN_AQUA, GPIO.FALLING, timeout=long_timeout_ms) is None:
#print('we are HIGH, no change')
continue
if GPIO.wait_for_edge(PIN_AQUA, GPIO.RISING, timeout=short_timeout_ms) is not None:
print(datetime.now(), 'we saw HIGH->LOW->HIGH change, ignoring')
continue
current = GPIO.LOW
#print('we re now LOW')
liters += 1
print(datetime.now(), liters)
try:
main()
except KeyboardInterrupt:
pass
finally:
GPIO.cleanup()