def collect_data(suffix):
global SAMPLE_RATE
global w1
global row
print "Now recording " + suffix
ipcon = IPConnection() # Create IP connection
imu = IMU(UID, ipcon) # Create device object
ipcon.connect(HOST, PORT) # Connect to brickd
# Don't use device before ipcon is connected
# Set period for quaternion callback to 1s
imu.set_all_data_period(SAMPLE_RATE)
imu.set_orientation_period(SAMPLE_RATE)
imu.set_quaternion_period(SAMPLE_RATE)
f1 = open('data/letters/all_data_'+suffix+'.csv', 'wb')
w1 = csv.writer(f1)
row = []
# Register quaternion callback
imu.register_callback(imu.CALLBACK_ALL_DATA, cb_all_data)
imu.register_callback(imu.CALLBACK_ORIENTATION, cb_orientation_data)
imu.register_callback(imu.CALLBACK_QUATERNION, cb_quaternion_data)
raw_input('Press key to quit recording ' + suffix + ' \n') # Use input() in Python 3
ipcon.disconnect()
