tacho.py

# -*- coding: utf-8 -*-

from time import sleep
import sys
from ev3dev import *

if __name__ == '__main__':
    if not EV3_BRICK:
        # Disable auto-detection of the brick (you have to set the correct address below)
        ev3.brick_addr = '192.168.0.204'

    if ev3_init() == -1: sys.exit( 1 )

    if not EV3_BRICK:
        print 'The EV3 brick auto-detection is DISABLED,'
        print 'waiting %s online with plugged tacho...' % ( ev3.brick_addr )
    else:
        print 'Waiting tacho is plugged...'

    while ev3_tacho_init() < 1: sleep( 1.0 )

    print '*** ( EV3 ) Hello! ***'

    print 'Found tacho motors:'
    for i in range( DESC_LIMIT ):
        type_inx = ev3_tacho_desc_type_inx( i )
        if type_inx != TACHO_TYPE__NONE_:
            print '  type =', ev3_tacho_type( type_inx )
            print '  port =', ev3_tacho_port_name( i )

    ok, sn = ev3_search_tacho( LEGO_EV3_M_MOTOR )
    if ok:
        print 'LEGO_EV3_M_MOTOR is found, run for 5 sec...'
        max_speed = get_tacho_max_speed( sn )
        print '  max_speed =', max_speed
        set_tacho_stop_action_inx( sn, TACHO_COAST )
        set_tacho_speed_sp( sn, max_speed * 2 / 3 )
        set_tacho_time_sp( sn, 5000 )
        set_tacho_ramp_up_sp( sn, 2000 )
        set_tacho_ramp_down_sp( sn, 2000 )
        set_tacho_command_inx( sn, TACHO_RUN_TIMED )
        # Wait tacho stop
        sleep( 0.1 )
        ok, flags = get_tacho_state_flags( sn )
        while ok and flags:
            ok, flags = get_tacho_state_flags( sn )

        print 'run to relative position...'
        set_tacho_speed_sp( sn, max_speed / 2 )
        set_tacho_ramp_up_sp( sn, 0 )
        set_tacho_ramp_down_sp( sn, 0 )
        set_tacho_position_sp( sn, 90 )
        for i in range( 8 ):
            set_tacho_command_inx( sn, TACHO_RUN_TO_REL_POS )
            sleep( 0.5 )
    else:
        print 'LEGO_EV3_M_MOTOR is NOT found'

    ev3_uninit()
    print '*** ( EV3 ) Bye! ***'