KC6050Servos.py

#!/usr/bin/python

# KC6050Servos.py Reads MPU6050 and also drives 2 servos
 
import smbus
import math
from Adafruit_PWM_Servo_Driver import PWM

# Initialise the PWM device using the default address
pwm = PWM(0x40)
# Note if you'd like more debug output you can instead run:
#pwm = PWM(0x40, debug=True)

servoMin = 150  # Min pulse length out of 4096
servoMax = 600  # Max pulse length out of 4096

# Power management registers
power_mgmt_1 = 0x6b
power_mgmt_2 = 0x6c
 
def read_byte(adr):
    return bus.read_byte_data(address, adr)
 
def read_word(adr):
    high = bus.read_byte_data(address, adr)
    low = bus.read_byte_data(address, adr+1)
    val = (high << 8) + low
    return val
 
def read_word_2c(adr):
    val = read_word(adr)
    if (val >= 0x8000):
        return -((65535 - val) + 1)
    else:
        return val
 
def dist(a,b):
    return math.sqrt((a*a)+(b*b))
 
def get_y_rotation(x,y,z):
    radians = math.atan2(x, dist(y,z))
    return -math.degrees(radians)
 
def get_x_rotation(x,y,z):
    radians = math.atan2(y, dist(x,z))
    return math.degrees(radians)
    
def setServoPulse(channel, pulse):
  pulseLength = 1000000                   # 1,000,000 us per second
  pulseLength /= 60                       # 60 Hz
  print "%d us per period" % pulseLength
  pulseLength /= 4096                     # 12 bits of resolution
  print "%d us per bit" % pulseLength
  pulse *= 1000
  pulse /= pulseLength
  pwm.setPWM(channel, 0, pulse)

pwm.setPWMFreq(60)                        # Set frequency to 60 Hz
 
bus = smbus.SMBus(1) # or bus = smbus.SMBus(1) for Revision 2 boards
address = 0x68       # This is the address value read via the i2cdetect command
 
# Now wake the 6050 up as it starts in sleep mode
bus.write_byte_data(address, power_mgmt_1, 0)
 
while (True):
  # Change speed of continuous servo on channel 11
  pwm.setPWM(11, 0, servoMin)
  time.sleep(1)
  pwm.setPWM(11, 0, servoMax)
  time.sleep(1)
  
  # Change speed of continuous servo on channel 15
  pwm.setPWM(15, 0, servoMin)
  time.sleep(1)
  pwm.setPWM(15, 0, servoMax)
  time.sleep(1)

  print "gyro data"
  print "---------"
 
  gyro_xout = read_word_2c(0x43)
  gyro_yout = read_word_2c(0x45)
  gyro_zout = read_word_2c(0x47)
 
  print "gyro_xout: ", gyro_xout, " scaled: ", (gyro_xout / 131)
  print "gyro_yout: ", gyro_yout, " scaled: ", (gyro_yout / 131)
  print "gyro_zout: ", gyro_zout, " scaled: ", (gyro_zout / 131)
 
  print
  print "accelerometer data"
  print "------------------"
 
  accel_xout = read_word_2c(0x3b)
  accel_yout = read_word_2c(0x3d)
  accel_zout = read_word_2c(0x3f)
 
  accel_xout_scaled = accel_xout / 16384.0
  accel_yout_scaled = accel_yout / 16384.0
  accel_zout_scaled = accel_zout / 16384.0
 
  print "accel_xout: ", accel_xout, " scaled: ", accel_xout_scaled
  print "accel_yout: ", accel_yout, " scaled: ", accel_yout_scaled
  print "accel_zout: ", accel_zout, " scaled: ", accel_zout_scaled
 
  print "x rotation: " , get_x_rotation(accel_xout_scaled, accel_yout_scaled, accel_zout_scaled)
  print "y rotation: " , get_y_rotation(accel_xout_scaled, accel_yout_scaled, accel_zout_scaled)