def main():
""" Main function running on uc. The part before while loop runs only once. """
# Declare device id. This one is first made.
device_id = '1'
# Declare all of the instances needed.
wireless = Wireless(id=device_id)
sensor = Max30102()
algorithm = HrSpOalgorithm()
display = Display()
led = Led()
data = Data()
# Connect with WiFi and MQTT.
wireless.wifi_connect()
wireless.mqtt_connect()
# Show WiFi connection status for 3 seconds. Clear the display when time elapse.
display.show_wifi_status(wireless.wifi_status())
utime.sleep(3)
display.clear()
# Set RTC.
if wireless.wifi_status():
settime()
# Prepare buffors responsible for collecting IR and RED leds data.
red_buf = []
ir_buf = []
time_buf = []
# Remember runtime just before running the while loop.
previous_time = utime.ticks_ms()
# Setup display before the while loop.
display.setup()
while True:
# Get actual date and time. Then split them to hh:mm:ss and dd.mm.yy formats. Display when done.
if wireless.wifi_status():
[y, m, d, h, min, s] = utime.localtime()[0:6]
h = 0 if h == 23 else h + 1
realtime = str("%02d" % h) + ':' + str("%02d" % min) + ':' + str("%02d" % s)
date = str("%02d" % d) + '.' + str("%02d" % m) + '.' + str(y)
else:
realtime ='--------'
date = '----------'
utime.sleep_ms(15)
display.show_time(realtime, date, device_id)
# Read values measured by sensor. Take time of measure in account as well.
red, ir, temperature = sensor.read_values()
time = utime.ticks_ms() - previous_time
# Determine if any body was detected by sensor based on IR value.
if ir <= 30000:
# No body was detected. Set the idle state and start the loop from the beginning.
display.idle_state()
sensor.set_idle_current()
continue
elif ir > 30000 and ir < 70000:
# Something was detected. Don't know what exactly though. Prepare algorithm and sensor to work.
# Start loop from the beginning.
algorithm.setup()
sensor.set_work_current()
continue
elif ir > 70000 and algorithm.beats == 0:
# Most likely the human body was detected. Set work state of display and go on with loop.
data.reset()
display.work_state()
# Collect measured values to buffors.
red_buf.append(int(red))
ir_buf.append(int(ir))
time_buf.append(time)
# At least 5 readings are needed to succesfully count the hr and spo2 values.
if len(red_buf) > 5:
red_buf = red_buf[1::]
ir_buf = ir_buf[1::]
time_buf = time_buf[1::]
elif len(red_buf) == 5:
pass
else:
continue
# Count moving average of obtained data. n samples are beineg averaged.
n = 5
red_averaged = algorithm.moving_average(red_buf, n)
ir_averaged = algorithm.moving_average(ir_buf, n)
time_averaged = algorithm.moving_average(time_buf, n)
# Get the last measured values.
ir_value = int(ir_averaged[-1])
red_value = int(red_averaged[-1])
now = time_averaged[-1]
# Try to count hr and spo2 values based on readings. Start loop from beggining if any error occured.
# Most of the time it is ZeroDivisionEror but except all errors to make sure device will not hang on.
try:
new, hr, spo2 = algorithm.count_hr_spo(ir_value, red_value, now)
except:
continue
# If new values gotten, and both of hr and spo2 are not zeros it can be assumed that proper value was obtained.
if new and hr != 0 and spo2 != 0:
# Save beat time and temperature rounded to two decimals as seperated variables. Just for convenience.
beat_time = int(algorithm.beat_time[-1])
temperature = round(temperature, 2)
# Turn on the led shortly just to inform that new data was received.
led.toggle()
# Display gotten values.
display.show_values(hr, spo2, temperature)
# Start verifying if any alarm was detected by making new, empty string variable. Then decide what type
# of alarm occured and add suitable information to alarm variable.
alarm =''
hr_min = 50
hr_max = 90
spo2_min = 93
temperature_max = 37
if hr < hr_min:
alarm += ('HR_TOO_LOW|')
elif hr > hr_max:
alarm += ('HR_TOO_HIGH|')
if spo2 < spo2_min:
alarm += ('SPO2_TOO_LOW|')
if temperature > temperature_max:
alarm += ('TEMP_TOO_HIGH')
# Show if alarm detected.
display.show_alarm(alarm=alarm)
# Check if connected to any broker. If not this point is loops end.
if wireless.mqtt_status:
# If alarm was not detected change it to '-'. PC app receiving data reads it like this.
if alarm == '':
alarm = '-'
# Update data with all needed values.
data.update(date, realtime, beat_time, hr, spo2, temperature, alarm )
# Send data to broker if 10 measures collected. Then reset the data buffor.
if data.check_amount() >= 10:
wireless.publish(ujson.dumps(data.get_buf()))
data.reset()