Created
March 15, 2019 12:29
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Water level control on RaspberryPi using HCSR04 sensor
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import sys | |
import traceback | |
import time | |
import json | |
from urllib.request import Request, urlopen | |
from urllib.error import URLError, HTTPError | |
import RPi.GPIO as GPIO | |
import cloud4rpi | |
from hcsr04sensor import sensor | |
TRIGGER_PIN = 17 # | |
ECHO_PIN = 27 # 13 | |
PUMP_PIN = 4 # 7 | |
BOUNCE_DELTA = 0.5 | |
SEND_INTERVAL = 30 # sec | |
MIN_SEND_INTERVAL = 1 # sec | |
MIN_DISTANCE = 6 # cm | |
MAX_DISTANCE = 9 # cm | |
STATUS_MSG_ERR = 'Sensor Error!' | |
STATUS_MSG_OK = 'Water Level OK' | |
STATUS_MSG_POURING = 'Water pouring' | |
STATUS_MSG_OVERFLOW = 'Overflow!' | |
ALERT_MSG = 'WARNING! dxPump is probably out of order...' | |
C4R_TOKEN = '__YOUR_DEVICE_TOKEN__' | |
HOOK_URL = '__CHANNEL_WEB_HOOK_URL__' | |
print('Connecting HCSR04 sensor...') | |
sens = sensor.Measurement(trig_pin=TRIGGER_PIN, | |
echo_pin=ECHO_PIN, | |
temperature=20, | |
unit='metric', | |
round_to=2, | |
gpio_mode=GPIO.BCM | |
) | |
GPIO.setmode(GPIO.BCM) | |
sent_time = -1 | |
prev_distance = -1 | |
pump_on = False | |
disableAlerts = False | |
def read_distance(): | |
try: | |
raw_measurement = sens.raw_distance(sample_size=5) | |
value = sens.distance_metric(raw_measurement) | |
return value if value < (MAX_DISTANCE * 2) else None | |
except Exception as err: | |
return None | |
def water_level_changed(prev, current): | |
return abs(round(prev, 2) - round(current, 2)) > BOUNCE_DELTA | |
def should_send(ts): | |
return time.time() - ts > SEND_INTERVAL | |
def toggle_pump(value): | |
print("[x] %s" % ('START' if value else 'STOP')) | |
global pump_on | |
pump_on = value | |
GPIO.setup(PUMP_PIN, GPIO.OUT) | |
GPIO.output(PUMP_PIN, pump_on) # Start/Stop pouring | |
def calc_water_level_percent(dist): | |
d = dist if dist else 0 | |
return (MAX_DISTANCE - d) / (MAX_DISTANCE - MIN_DISTANCE) * 100 | |
def notify(msg): | |
global disableAlerts | |
if disableAlerts: | |
return | |
print('[x] Notification: ', msg) | |
req = Request(HOOK_URL) | |
try: | |
data = json.dumps({'text': msg}).encode('ascii') | |
response = urlopen(req, data) | |
response.read() | |
disableAlerts = True | |
except HTTPError as e: | |
print("Request failed: %d %s", e.code, e.reason) | |
except URLError as e: | |
print("Server connection failed: %s", e.reason) | |
def send(cloud, variables, dist, error=False): | |
global pump_on | |
percent = calc_water_level_percent(dist) | |
variables['Distance']['value'] = dist | |
variables['WaterLevel']['value'] = percent | |
variables['PumpRelay']['value'] = pump_on | |
variables['Status']['value'] = STATUS_MSG_ERR if error \ | |
else STATUS_MSG_OVERFLOW if percent > 110 else STATUS_MSG_POURING if pump_on else STATUS_MSG_OK | |
current = time.time() | |
global sent_time | |
if current - sent_time > MIN_SEND_INTERVAL: | |
readings = cloud.read_data() | |
cloud.publish_data(readings) | |
sent_time = current | |
def main(): | |
variables = { | |
'Distance': { | |
'type': 'numeric', | |
}, | |
'Status': { | |
'type': 'string', | |
}, | |
'PumpRelay': { | |
'type': 'bool', | |
'value': False | |
}, | |
'WaterLevel': { | |
'type': 'numeric', | |
}, | |
} | |
cloud = cloud4rpi.connect(C4R_TOKEN, 'mq.stage.cloud4rpi.io') | |
cloud.declare(variables) | |
cloud.publish_config() | |
try: | |
print('Start reading distance...') | |
n = 0 | |
while True: | |
n += 1 | |
distance = read_distance() | |
if distance is None: | |
notify(ALERT_MSG) | |
send(cloud, variables, distance, True) | |
continue | |
print("#%d Distance = %.2f (cm)" % (n, distance)) | |
if distance < MIN_DISTANCE: | |
toggle_pump(0) | |
send(cloud, variables, distance) | |
if distance > MAX_DISTANCE: | |
toggle_pump(1) | |
send(cloud, variables, distance) | |
global prev_distance | |
if should_send(sent_time) or water_level_changed(prev_distance, distance): | |
send(cloud, variables, distance) | |
prev_distance = distance | |
global disableAlerts | |
disableAlerts = False | |
except Exception as e: | |
print('FAILED:', e) | |
traceback.print_exc() | |
finally: | |
GPIO.cleanup() | |
sys.exit(0) | |
if __name__ == '__main__': | |
main() |
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