kitty.py

from threading import Lock

import json
import serial

import gps as gpsd

from rowind import Rowind

import boatd
#assert boatd.VERSION == 1.1

class Arduino(object):
    '''The arduino and basic communications with devices attached to it'''
    def __init__(self, port=None):
        try:
            self.port = serial.Serial(port)
        except Exception as e:
            raise IOError('Cannot connect to arduino on {} - {}'.format(port, e))
        self._lock = Lock()
        self.port.readline()

    def read_json_line(self):
        '''Return a decoded line'''
        with self._lock:
            return json.loads(self.port.readline())

    def send_command(self, c):
        '''
        Send a short command, and return a single line response. Prevents
        other threads interweaving requests by locking on self._lock
        '''
        with self._lock:
            self.port.flushInput()
            self.port.write(c + '\n')
            return json.loads(self.port.readline())

    def get_compass(self):
        '''Return the heading from the compass in degrees'''
        return self.send_command('c').get('compass')

    def set_rudder(self, amount):
        '''Set the rudder to an amount between 1000 and 2000'''
        return self.send_command('r{}'.format(amount)).get('rudder')

    def set_sail(self, amount):
        '''Set the sail to an amount between 1000 and 2000'''
        return self.send_command('s{}'.format(amount)).get('sail')


class KittyDriver(boatd.BaseBoatdDriver):
    def __init__(self):
        self.arduino = Arduino('/dev/arduino')
        self.rowind = Rowind('/dev/rowind')
        self.gps = gpsd.gps(mode=gpsd.WATCH_ENABLE)
        self.previous_lat = 0
        self.previous_long = 0
        
    def heading(self):
        return self.arduino.get_compass()

    def wind_direction(self):
        self.rowind.update()
        return self.rowind.direction
    
    def wind_speed(self):
        self.rowind.update()
        return self.rowind.speed
    
    def position(self):
        if self.gps.waiting(timeout=2):
            fix = self.gps.next()
            i = 0
            while fix['class'] != 'TPV':
                if self.gps.waiting(timeout=2) and i < 15:
                    fix = self.gps.next()
                    i += 1
                else:
                    return (self.previous_lat, self.previous_long)

            self.previous_lat = fix.lat
            self.previous_long = fix.lon
            return (fix.lat, fix.lon)

        else:
            return (self.previous_lat, self.previous_long)

    def rudder(self, angle):
        ratio = (1711/22.5) / 8 # ratio of angle:microseconds
        amount = 1500 + (angle * ratio)
        self.arduino.set_rudder(amount - 65)
    
    def sail(self, angle):
        self.arduino.set_sail(angle)

driver = boatd.Driver()


if __name__ == '__main__':
    import time
    a = Arduino('/dev/arduino')
    print a.get_compass()
    print a.set_rudder(0)
    print a.set_sail(0)