Reads rangefinder distance

range.py

#
# This example shows how to use DroneKit-Python to get and set vehicle state, parameter and channel-override information. 
# It also demonstrates how to observe vehicle attribute (state) changes. 
# 
# Usage:
# * mavproxy.py
# * module load api
# * api start range.py
#
from droneapi.lib import VehicleMode
from pymavlink import mavutil
import time, json

# First get an instance of the API endpoint
api = local_connect()
# Get the connected vehicle (currently only one vehicle can be returned).
v = api.get_vehicles()[0]

# Demo callback handler for raw MAVLink messages
def mavrx_debug_handler(message):
    if message.get_type() == 'RANGEFINDER':
    	print 'received packet...'
    	print 'distance:', message.distance
    	print 'voltage:', message.voltage

# Set MAVLink callback handler (after getting Vehicle instance)
v.set_mavlink_callback(mavrx_debug_handler)