# pyMate controller
# Author: Jared Sanson <jared@jared.geek.nz>
#
# Allows communication with an Outback Systems MATE controller panel,
# which provides diagnostic information of current charge state and power use
#
# Currently only supports the MX status page (from an Outback MX charge controller)
#
# NOTE: This is intended for communication with the MATE's RS232 port, not Outback's proprietary protocol.

import serial
import csvmake
import datetime

from value import Value
from time import gmtime, strftime

class MXStatusPacket(object):
    """
    Represents an MX status packet, containing useful information
    such as charge current and PV voltage.
    """
    def __init__(self, packet):
        fields = packet.split(',')
        self.address = fields[0]
        self.timestamp = strftime('%Y-%m-%d %H:%M:%S', gmtime())
        # fields[1] unused
        self.charge_current = Value(float(fields[2]) + (float(fields[6]) / 10.0), resolution=1)
        self.pv_current = Value(fields[3], resolution=0)
        self.pv_voltage = Value(fields[4], resolution=0)
        self.daily_kwh = Value(float(fields[5]) / 10.0, resolution=1)
        self.aux_mode = fields[7]
        self.error_mode = fields[8]
        self.charger_mode = fields[9]
        self.bat_voltage = Value(float(fields[10]) / 10, resolution=1)
        self.daily_ah = Value(float(fields[11]), resolution=1)
	# fields[12] unused

        chk_expected = int(fields[13])
        chk_actual = sum(ord(x)-48 for x in packet[:-4] if ord(x)>=48)
        if chk_expected != chk_actual:
            raise Exception("Checksum error in received packet")


class MateCom(object):
    """
    Interfaces with the MATE controller on a specific COM port.
    Must be a proper RS232 port with RTS/DTR pins.
    """
    def __init__(self, port, baudrate=19200):
        self.ser = serial.Serial(port, baudrate, timeout=2)

        # Provide power to the Mate controller
        self.ser.setDTR(True)
        self.ser.setRTS(False)

        self.ser.readline()

    def read_status(self):
        ln = self.ser.readline().strip()
        return MXStatusPacket(ln) if ln else None


if __name__ == "__main__":
    # Test
    mate = MateCom('COM3')
    status = mate.read_status()
    #print status.__dict__
    print 'Writing to CSV'
    csvmake.write_to_csv(status.__dict__)
    print 'CSV Output written'
    #{'charger_mode': '00', 'error_mode': '000', 'pv_voltage': 18V, 'charge_current': 0.0A, 'daily_kwh': 7.8kWh, 'daily_ah': 144.0Ah, 'pv_current': 0A, 'address': 'A', 'aux_mode': '03', 'bat_voltage': 51.1V}