为了便于调试，特意写了一个通过键盘控制机械臂舵机的代码，来调试舵机，代码是基于teleop_twist_keyboard修改的。在arduino_node.py中已经声明了舵机读和写的ROS Service：
# A service to position a PWM servo
rospy.Service(\'~servo_write\', ServoWrite, self.ServoWriteHandler)
# A service to read the position of a PWM servo
rospy.Service(\'~servo_read\', ServoRead, self.ServoReadHandler)- 1
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- 4
- 5
配合上一篇微博中arduino端的舵机驱动，我们只需要实现这两个ROS Service的client就可以控制舵机了，具体原理请看代码中的注释代码如下：
#!/usr/bin/env python
import roslib; roslib.load_manifest(\'teleop_twist_keyboard\')
import rospy
from geometry_msgs.msg import Twist
from ros_arduino_msgs.srv import *
from math import pi as PI
import sys, select, termios, tty
msg = """
Reading from the keyboard and Publishing to Twist, Servo or sensor!
---------------------------
Moving around:
u i o
j k l
, : up (+z)
. : down (-z)
m : stop
----------------------------
Left arm servo control:控制机器人左臂，每次调整0.09弧度
+ 1 2 3 4 5 6
- q w e r t y
----------------------------
Right arm servo control:控制机器人右臂，每次调整0.09弧度
+ a s d f g h
- z x c v b n
p : init the servo 初始化舵机
CTRL-C to quit
"""
moveBindings = {
\'i\':(1,0,0,0),
\'o\':(1,0,0,1),
\'j\':(-1,0,0,-1),
\'l\':(-1,0,0,1),
\'u\':(1,0,0,-1),
\'k\':(-1,0,0,0),
\',\':(0,0,1,0),
\'.\':(0,0,-1,0),
}
#右臂舵机的控制数组，1表示增加0.09弧度，0表示减少0.09弧度
rightArmServo={
\'1\':(0,1),
\'2\':(1,1),
\'3\':(2,1),
\'4\':(3,1),
\'5\':(4,1),
\'6\':(5,1),
\'q\':(0,0),
\'w\':(1,0),
\'e\':(2,0),
\'r\':(3,0),
\'t\':(4,0),
\'y\':(5,0),
}
#左臂舵机的控制数组，1表示增加0.09弧度，0表示减少0.09弧度
leftArmServo={
\'a\':(6,1),
\'s\':(7,1),
\'d\':(8,1),
\'f\':(9,1),
\'g\':(10,1),
\'h\':(11,1),
\'z\':(6,0),
\'x\':(7,0),
\'c\':(8,0),
\'v\':(9,0),
\'b\':(10,0),
\'n\':(11,0),
}
#手臂臂舵机的控制命令数组
armCmd={
\'[\':(0,1),#左臂初始化
\']\':(1,1),#右臂初始化
}
def getradians(angle):
return PI*angle/180
def getKey():
tty.setraw(sys.stdin.fileno())
select.select([sys.stdin], [], [], 0)
key = sys.stdin.read(1)
termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)
return key
#舵机当前位置读取，调用servo_read service
def servoRead(servoNum):
rospy.wait_for_service(\'/arduino/servo_read\')
try:
readServo=rospy.ServiceProxy(\'/arduino/servo_read\',ServoRead)
return readServo(servoNum)
except rospy.ServiceException, e:
print "Service call failed: %s"%e
#舵机位置写，根据舵机标号设置舵机的位置0~π,注意这里的value对应的是弧度
def servoWrite(servoNum, value):
rospy.wait_for_service(\'/arduino/servo_write\')
try:
servo_write=rospy.ServiceProxy(\'/arduino/servo_write\',ServoWrite)
servo_write(servoNum,value)
print servoNum
print value
except rospy.ServiceException, e:
print "Service call failed: %s"%e
#初始化右臂舵机角度，要根据实际情况调整舵机角度
def initRightArm():
servoWrite(0,getradians(60))
servoWrite(1,getradians(80))
servoWrite(2,getradians(90))
servoWrite(3,getradians(90))
servoWrite(4,getradians(90))
servoWrite(5,getradians(90))
#初始化左臂舵机角度，要根据实际情况调整舵机角度
def initLeftArm():
servoWrite(6,getradians(90))
servoWrite(7,getradians(90))
servoWrite(8,getradians(90))
servoWrite(9,getradians(90))
servoWrite(10,getradians(90))
servoWrite(11,getradians(90))
def vels(speed,turn):
return "currently:\tspeed %s\tturn %s " % (speed,turn)
if __name__=="__main__":
settings = termios.tcgetattr(sys.stdin)
pub = rospy.Publisher(\'cmd_vel\', Twist, queue_size = 1)
rospy.init_node(\'teleop_twist_keyboard\')
speed = rospy.get_param("~speed", 0.5)
turn = rospy.get_param("~turn", 1.0)
x = 0
y = 0
z = 0
th = 0
status = 0
try:
print msg
print vels(speed,turn)
while(1):
key = getKey()
print key
if key in moveBindings.keys():
x = moveBindings[key][0]
y = moveBindings[key][1]
z = moveBindings[key][2]
th = moveBindings[key][3]
elif key in leftArmServo.keys():#左臂舵机控制
value=servoRead(leftArmServo[key][