Cameteo/circuitpython/code/cameteo.py

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

"""Cameteo module

Data classes for GPS, BME280 sensors and some system stuff
Function to handle data files rotation and set internal RTC date from other
(more reliable) sources.
"""

import os
import time
import rtc
import microcontroller
import board
from busio import I2C, UART
from analogio import AnalogIn
from digitalio import DigitalInOut, Direction
from adafruit_bme280 import Adafruit_BME280_I2C
from adafruit_gps import GPS

TIME_FORMAT = "{:04}/{:02}/{:02}_{:02}:{:02}:{:02}"     # Date/time format

# Set the pin N°13 to use the onboard LED as read-only/read-write indicator
# (RED = read-only, no data recorded)
LED13 = DigitalInOut(board.D13)
LED13.direction = Direction.OUTPUT
LED13.value = False

###########
# Classes #
###########

class Data:
    """Class for handling data"""

    def __init__(self,
                 name,
                 update_interval=10,
                 write_interval=300,
                 send_interval=60,
                 debug=False):

        self.name = name
        self.data = {}
        self.debug = debug
        self.update_interval = update_interval
        self.write_interval = write_interval
        self.send_interval = send_interval
        self._last_update = 0
        self._last_backup = 0
        self._last_send = 0
        self._last_file_rotation = time.localtime()

        # Check if data directories exists if we need to use them
        if self.write_interval >= 0:
            try:
                if 'data' not in os.listdir():
                    os.mkdir('data')
                    os.mkdir('data/hourly')
                    os.mkdir('data/daily')
                elif 'hourly' not in os.listdir('data'):
                    os.mkdir('data/hourly')
                elif 'daily' not in os.listdir('data'):
                    os.mkdir('data/daily')
            except OSError as err:
                print("Err {}: readonly".format(err))
                self.write_interval = -1  # to avoid trying again till next reset
                # Turn onboard led on to indicate read-only error
                LED13.value = True

    def __str__(self):
        """Serialize data for visualization on serial console"""
        output = self.name + ":\n"
        for item in self.data.items():
            output += "\t{0}: {1}\n".format(*item)
        return output

    def __repr__(self):
        return self.json

    def update(self, current, verbose=True):
        """Read the data from sensors and update the data dict variable"""
        if self.debug:
            print("Update {} : Current : {} | Last : {}  | Interval : {}".format(
                self.name,
                current,
                self._last_update,
                self.update_interval))
        if current - self._last_update >= self.update_interval:
            self._last_update = current
            self._update()
            if verbose:
                print(self)

    def _update(self):
        """Here comes specific update code"""
        pass

    @property
    def json(self):
        """Serialized data to compact json-formatted string"""
        output = '{"' + self.name + '":{'
        first_data = True
        for name, value in self.data.items():
            if first_data:
                comma = ""
                first_data = False
            else:
                comma = ","
            output = '{}{}"{}":"{}"'.format(output, comma, name, value)
        output = output + '}}'
        return output

    def csv(self, header=False):
        """Serialized data values (or keys if header=True) as CSV line"""
        if header:
            return ";".join([str(x) for x in self.data.keys()])

        return ";".join([str(x) for x in self.data.values()])

    def write_on_flash(self, current, verbose=True):
        """Save the current data as csv file on SPI flash"""
        if self.write_interval >= 0:
            if self.debug:
                print("Write {} : Current : {} | Last : {}  | Interval : {}".format(
                    self.name,
                    current,
                    self._last_backup,
                    self.write_interval))
            if current - self._last_backup >= self.write_interval:
                self._last_backup = current
                #First check if a rotation is needed
                self._file_rotation()

                file_name = "{}.csv".format(self.name)
                file_path = "data"
                try:
                    #Check if the file exists. If not, creates it with CSV header
                    if file_name not in os.listdir(file_path):
                        with open("/".join((file_path, file_name)), "w") as csv_file:
                            csv_file.write(self.csv(header=True))
                            csv_file.write("\n")
                            if verbose:
                                print("File created : {}".format(file_name))

                    with open("/".join((file_path, file_name)), "a") as csv_file:
                        csv_file.write(self.csv())
                        csv_file.write("\n")
                        if verbose:
                            print("Written data : \n{}".format(self.csv()))

                except OSError as err:
                    print("Err {}: readonly".format(err))
                    # to avoid trying again till next reset
                    self.write_interval = -1
                    # Turn onboard led on to indicate read-only filesystem
                    LED13.value = True

    def send_json(self, current, uart, verbose=True):
        """Send JSON string over UART"""
        if self.debug:
            print("Send {} : Current : {} | Last : {}  | Interval : {}".format(
                self.name,
                current,
                self._last_send,
                self.send_interval))
        if current - self._last_send >= self.send_interval:
            self._last_send = current
            uart.write(self.json)
            uart.write("\n")
            if verbose:
                print(self.json)
                #print("\n")

    def _file_rotation(self):
        """Check if files need to rotate
        => every new hour
        => every new day
        """
        current_time = time.localtime()
        if self.debug:
            print(self._last_file_rotation[3])
            print(current_time[3])

        # If the hour changed : copy current csv to hourly directory
        if current_time[3] != self._last_file_rotation[3]:
            print("Time to move hourly data !")
            os.rename("data/{}.csv".format(self.name),
                      "data/hourly/{}_{:02}.csv".format(
                          self.name,
                          self._last_file_rotation[3]))

            # If the day changed : copy content of hourly to daily directories
            if current_time[2] != self._last_file_rotation[2]:
                print("Time to move daily data !")
                # Create new dir for the date of "yesterday"
                newdir = "{}{:02}{:02}".format(*self._last_file_rotation[0:3])
                if newdir not in os.listdir("data/daily/"):
                    os.mkdir("data/daily/" + newdir)
                # Move each "hourly file" to the new directory
                for file in os.listdir('data/hourly'):
                    # Move only file which name is beginning with self.name
                    if file.find(self.name) == 0:
                        print("Move {} to {}".format(file, newdir))
                        os.rename("data/hourly/{}".format(file), "{}/{}".format(newdir, file))

        #Finally : remember last rotation check
        self._last_file_rotation = current_time

        return

class SysData(Data):
    """Subclass for Feather board data"""

    def __init__(self, name="SYS", update_interval=10, write_interval=300,
                 send_interval=60, debug=False):

        Data.__init__(self, name=name,
                      update_interval=update_interval,
                      write_interval=write_interval,
                      send_interval=send_interval,
                      debug=debug)

        self.data = {'time': "2000/01/01_00:00:00",
                     'vbat': int(),
                     'cput': float()}

        # Battery voltage
        self.vbat = AnalogIn(board.VOLTAGE_MONITOR)
        self._rtc = rtc.RTC()

    def _update(self):
        """ Update data from Feather board"""
        self.data['time'] = TIME_FORMAT.format(*self._rtc.datetime[0:6])
        self.data['cput'] = round(microcontroller.cpu.temperature, 2)

        # Note about v_bat calculation :
        # 0.000100708 = 2*3.3/65536 with
        #  2 : voltage is divided by 2
        #  3.3 : Vref = 3.3V
        #  65536 : 16bit ADC
        val = 0
        samples = 10
        for sample in range(samples):
            val += self.vbat.value
            time.sleep(0.01)
        self.data['vbat'] = round(val/samples*0.000100708, 3)


class BME280Data(Data):
    """Subclass for BME280 sensor"""

    def __init__(self, name="BME", update_interval=10, write_interval=300,
                 send_interval=60, debug=False):

        Data.__init__(self, name=name,
                      update_interval=update_interval,
                      write_interval=write_interval,
                      send_interval=send_interval,
                      debug=debug)

        self.data = {'time' : "2000/01/01_00:00:00",
                     'temp': float(),
                     'hum':  int(),
                     'press': float()}
        # BME280 sensors (I2C)
        # i2c addresses for BME280 breakout :
        #   0x77 = adafruit breakout board
        #   0x76 = tiny cheap chinese board
        self.bme280 = Adafruit_BME280_I2C(I2C(board.SCL, board.SDA),
                                          address=0x76)

    def _update(self):
        """Update data from BME280"""
        self.data['time'] = TIME_FORMAT.format(*time.localtime()[0:6])
        self.data['temp'] = round(self.bme280.temperature, 1)
        self.data['hum'] = int(self.bme280.humidity)
        self.data['press'] = round(self.bme280.pressure, 2)

    def rgb(self, neopixel_max=70):
        """Convert atmospheric data from BME280 sensor into NeoPixel color as
        a tuple (RED, BLUE, GREEN):
         * RED => temperature : max = 35degC, min =10degC (range 25°C)
         * BLUE => humidity : max= 100%, mini=0%
         * GREEN => pression : mini=960hPa, maxi = 1030hPa (range 70hPa)
        """
        # RED componant calculation from temperature data
        # 10 is the min temperature, 25 is the range
        # (10+25=35°C = max temperature)
        red = int((self.data['temp']-10)*neopixel_max/25)
        if red > neopixel_max:
            red = neopixel_max
        if red < 0:
            red = 0

        # BLUE componant calculation: very simple! By definition relative
        #  humidity cannot be more than 100 or less than 0, physically
        blue = int(self.data['hum']*neopixel_max/100)

        # GREEN component calculation : 960 is the minimum pressure and 70 is
        #  the range (960+70 = 1030hPa = max pressure)
        green = int((self.data['press']-960)*neopixel_max/70)
        if green > neopixel_max:
            green = neopixel_max
        if green < 0:
            green = 0

        if self.debug:
            print("Col:{}".format((red, green, blue)))

        return (red, green, blue)


class GPSData(Data):
    """Sub class for GPS"""

    def __init__(self, name="GPS",
                 update_interval=0, write_interval=60, send_interval=60,
                 enable=True, enable_pin=DigitalInOut(board.A5),
                 debug=False):

        Data.__init__(self, name=name,
                      update_interval=update_interval,
                      write_interval=write_interval,
                      send_interval=send_interval,
                      debug=debug)

        self.data = {'time': "2000/01/01_00:00:00",
                     'lat': float(),
                     'lon': float(),
                     'alt': float(),
                     'qual': int(),
                     'age': int()}
        self._enable = enable
        self._gps_last_fix = int()
        self._gps_current_fix = int()

        # Set the pin to control the power to GPS module
        self._gps_en_pin = enable_pin
        self._gps_en_pin.direction = Direction.OUTPUT

        self._gps = GPS(UART(board.TX, board.RX, baudrate=9600, timeout=3000)) #, debug=self.debug)

        if self._enable:
            self.enable()
        else:
            self.disable()

    def _update(self):
        self._gps.update()

        if self._enable:
            self._gps_current_fix = int(time.monotonic())
            if self._gps.timestamp_utc is not None:
                self.data['time'] = TIME_FORMAT.format(*self._gps.timestamp_utc[0:6])
            else:
                self.data['time'] = TIME_FORMAT.format(2018, 9, 10, 10, 0, 0)
            if self._gps.has_fix:
                self._gps_last_fix = self._gps_current_fix
                self.data['lat'] = self._gps.latitude
                self.data['lon'] = self._gps.longitude
                self.data['alt'] = self._gps.altitude_m
                self.data['qual'] = self._gps.fix_quality
                self.data['age'] = 0
            else:
                self.data['age'] = int(self._gps_current_fix - self._gps_last_fix)
        else:
            self.data = {}

    def enable(self):
        """Enable GPS module"""
        # Set GPS module on FeatherWing board

        if not self._enable:
            self._enable = True
            self._gps_en_pin.value = not self._enable  # Set enable pin high to disable GPS module
            time.sleep(0.1)

            # Turn on the basic GGA and RMC info
            self._gps.send_command('PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0')
            self._gps.send_command('PMTK220,1000')    # 1000 ms refresh rate

    def disable(self):
        """Disable GPS module"""
        if self._enable:
            self._enable = False
            self._gps_en_pin.value = not self._enable  # Set enable pin high to disable GPS module

    @property
    def datetime(self):
        """Wrapper to feed rtc.set_time_source()"""
        return self._gps.timestamp_utc


#############
# Functions #
#############

def set_clock_from_localtime(clock, threshold=2.0, debug=False):
    """
    Compare internal RTC and date-time from time.localtime() and set
    the RTC date/time to this value if the difference is more or equal to
    threshold (in seconds).
    The source of time.localtime() can be set with rtc.set_time_source()
    """

    if debug:
        print("Clock date/time : " + TIME_FORMAT.format(*clock.datetime[0:6]))
        print("Local date/time : " + TIME_FORMAT.format(*time.localtime()[0:6]))

    # Check if time.localtime() is valid and can be converted in seconds
    try:
        local_seconds = time.mktime(time.localtime())
    except OverflowError as err:
        print(err)
        print("Local time source : " + TIME_FORMAT.format(*time.localtime()[0:6]))
        print("Wait some time to have proper time from time source...")
        return 1

    # Max difference between GPS and internal RTC (in seconds):
    if abs(local_seconds - time.mktime(clock.datetime)) >= threshold:
        print("Clock difference with GPS!")
        print("Previous date/time : " + TIME_FORMAT.format(*clock.datetime[0:6]))
        clock.datetime = time.localtime()  # Trust localtime if there is a bias
        print("Clocks synced !")

    return 0