Yeah, the example isn't that well illustrated
The reason for the error message is that you are creating the log configuration before you have connected and at this point you do not know what is in the TOC. If you try to add a log configuration then you will not be able to since it's not possible to verify that the variables are in the TOC. In the example on the wiki the log configuration is created in the connected callback and at this point the TOC has been downloaded so the configuration can be verified when it's created.
After the log configuration has been successfully created and you are connected the threads in the cflib will do callbacks to the selected function each time new data is received, you do not have to poll for it.
Here's a quick rewrite of the code (untested and dirty) but hopefully it shows the concept a bit better:
Code: Select all
import cflib.crtp
from cfclient.utils.logconfigreader import LogConfig
from cfclient.utils.logconfigreader import LogVariable
from cflib.crazyflie import Crazyflie
class Main:
def __init__(self):
self.crazyflie = Crazyflie()
cflib.crtp.init_drivers()
self.crazyflie.connectSetupFinished.add_callback(
self.connectSetupFinished)
self.crazyflie.open_link("radio://0/10/250K")
def connectSetupFinished(self, linkURI):
# Set accelerometer logging config
accel_log_conf = LogConfig("Accel", 10)
accel_log_conf.addVariable(LogVariable("acc.x", "float"))
accel_log_conf.addVariable(LogVariable("acc.y", "float"))
accel_log_conf.addVariable(LogVariable("acc.z", "float"))
# Now that the connection is established, start logging
self.accel_log = self.crazyflie.log.create_log_packet(accel_log_conf)
if self.accel_log is not None:
self.accel_log.dataReceived.addCallback(log_accel_data)
self.accel_log.start()
else:
print("acc.x/y/z not found in log TOC")
def log_accel_data(self, data):
logging.info("Accelerometer: x=%.2f, y=%.2f, z=%.2f" %
(data["acc.x"], data["acc.y"], data["acc.z"]))
Main()
