Remote Tank Control using Android SL4A + Bluetooth

uibtre.py

# Video of the code in action: http://www.youtube.com/watch?v=BtmRBxRsMk4
#! python
# -= encoding=utf-8 =-
##############################################################################
#
# uibtre.py $Rev:$
# $Id$
#
# Copyright (c) 2011, shimoda as kuri65536 _dot_ hot mail _dot_ com
#                       ( email address: convert _dot_ to . and joint string )
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without modification, are permitted
# provided that the following conditions are met:
#
# - Redistributions of source code must retain the above copyright notice, this list of conditions and
#   the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright notice, this list of conditions
#   and the following disclaimer in the documentation and/or other materials provided with the
#   distribution.
# - Neither the name of the <ORGANIZATION> nor the names of its contributors may be used to endorse or
#   promote products derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
# FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
# IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
##############################################################################
import sys
import time
import android

def convertChar( x, y ):
    """convert y to power => 100 to 255,
       convert x to ratio of left and right.

       y range
        :10 to  5:      => stop motor
        : 5 to -2:      => 100 to 255 motor
        :-2 to -7:      => power 255
        :-7 to -10:     => stop program

       x range::
        :-10 to -7:     => left 100%, right 0%
        :-7  to -4:     => left 0 to 100%
        :-4  to 4 :     => left and right = 100%
        : 4  to 7 :     => right 0 to 100%
        : 7  to 10:     => left 0%, right 100%
    """
    if y > 5.:
        return 'S000S000'

    power = ( 5. - y ) / 7. * 155 + 100
    power = power > 0 and power or 0
    power = power > 255 and 255 or power

    l = ( x + 8 ) / 6.0     ### -2 to -8 => 1 to 0
    r = ( 8 - x ) / 6.0     ###  2 to 8 => 1 to 0

    l = l > 1 and 1 or l    ### limit to -inf to 1.
    r = r > 1 and 1 or r

    l = l > 0 and l or 0    ### limit to 0 to 1
    r = r > 0 and r or 0

    if l == r == 0:
        l = r = power
    elif r == 1:
        r = power * l
        l = power
    elif l == 1:
        l = power * r
        r = power

    l = l > 99 and l or 0
    r = r > 99 and r or 0

    return 'F%03dF%03d' % ( l, r )

d = android.Android()

def startbluetooth():
    uuid = '00001101-0000-1000-8000-00805F9B34FB'
    d.dialogCreateAlert( "select BlueTooth operation" )
    d.dialogSetPositiveButtonText( "server" )
    d.dialogSetNeutralButtonText( "client" )
    d.dialogSetNegativeButtonText( "no-BT" )
    d.dialogShow()
    ret = d.dialogGetResponse().result[ "which" ]

    if ret == "positive":
        d.bluetoothMakeDiscoverable()
        d.bluetoothAccept( uuid )
        return True
    elif ret == "neutral":
        ret = d.bluetoothConnect( uuid ).result
        if not ret:
            d.makeToast( "bluetooth not connected" )
            sys.exit( 0 )
        return True
    print "skip bt setup"
    return False

def main():
    d.startSensingTimed( 2, 300 )   ### sense start

    fBT = startbluetooth()
    d.dialogCreateHorizontalProgress( "accelerometer", "Hello robo", 200 )
    d.dialogShow()
    while True:
        time.sleep( 0.3 )
        x, y, z = d.sensorsReadAccelerometer().result
        print "sense: ", x, y, z
        if not y:
            continue
        if y < -3.0:
            break
        d.dialogSetCurrentProgress( 100. + 10.*( y - 6 ) )
        fBT and d.bluetoothWrite( convertChar( x, y ) )

    fBT and d.bluetoothWrite( 'S000S000' ) ### added Stop-command
    d.dialogDismiss()

if __name__ == "__main__":
    main()

# vi: ft=python:et:ts=4