Bitcraze Forums

Posted: **Tue Oct 12, 2021 11:17 am**

Dear all,

I got some issues with the multiranger deck:

When I used the python scripts as below: I put the crazyflie in the corridor without any obstacle. The distance to the wall is far than 4m.

Code: Select all

cflib.crtp.init_drivers()
with SyncCrazyflie(URI, cf=Crazyflie(rw_cache='./cache')) as scf:
	with Multiranger(scf) as multiranger:
		for _ in range(100):
			print(multiranger.front)
			time.sleep(0.05)

The printed outputs were not all None but started with three None and then some value between 0.249 to 0.259

However When I did not add the time delay like:

Code: Select all

cflib.crtp.init_drivers()
with SyncCrazyflie(URI, cf=Crazyflie(rw_cache='./cache')) as scf:
	with Multiranger(scf) as multiranger:
		for _ in range(100):
			print(multiranger.front)

The outputs were None.

Could anyone tell me the reasons?

Cheers!

Posted: **Wed Oct 13, 2021 7:56 am**

I have also seen some odd behavior when our of range. It needs more investigation and I created an issue for it https://github.com/bitcraze/crazyflie-f ... issues/874
Please feel free to add any information you know of to the issue.

Posted: **Mon Nov 29, 2021 5:30 pm**

We are also seeing strange behavior when the multiranger is out of range. The attached image is an experiment I made, where I moved the crazyflie from one wall (left sensor - green line) to the other (right sensor - blue line). The left sensor starts at a small value and increases as I move away from the wall. When I reach the maximum range (around 395 on the horizontal axis) there is a high increase in the noise and then the sensor starts to report a short range, which increases as I keep moving farther and farther. This behavior is mirrored by the opossite sensor.

Posted: **Wed Dec 01, 2021 9:02 am**

Thanks!

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Multiranger deck wrong distance measurement

Multiranger deck wrong distance measurement

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