Radio Signal Intensity
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Radio Signal Intensity
Hi!!
Does someone know a way to read the intensity of the Radio signal from the dongle??? I was thinking that it could be a good sensor of distance.
Marco
Does someone know a way to read the intensity of the Radio signal from the dongle??? I was thinking that it could be a good sensor of distance.
Marco
Re: Radio Signal Intensity
That is a little drawback with the nRF24L01+, there is no RSSI to get a signal strength measurement from. It is possible to use the packet retries as a rough measurement though but as there are so many things that effect the packet retries I don't know how well it would really work.
The crazyradio.py contains the send_packet function which returns number of retries (retransmits). It is then used in the CRTP layer in radioediver.py as a callback link_quality_callback. The Crazyflie class takes care of that callback with _link_quality_cb and is finally used in the GUI.
The crazyradio.py contains the send_packet function which returns number of retries (retransmits). It is then used in the CRTP layer in radioediver.py as a callback link_quality_callback. The Crazyflie class takes care of that callback with _link_quality_cb and is finally used in the GUI.
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Re: Radio Signal Intensity
it is a realy pity!! I think that the number of retries is quite different for the intensity of the signal
So i cant use it for my purpose. Do you know if there could be another way to estimate the distance of the crazy flie from the dongle?
So i cant use it for my purpose. Do you know if there could be another way to estimate the distance of the crazy flie from the dongle?
Re: Radio Signal Intensity
Wondering, what is "your purpose" in the first place?
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Re: Radio Signal Intensity
I read that the nRF24L01+ has a Received Power Detector measurements that is only a 1bit
But i think that is not enough for measure the distance!
But has the crazyflie the same tool or is different?? My ambition is have two crazyflies that can comunicate each other and measure their relative distance.
.from the datasheet: Received Power Detector (RPD), located in register 09, bit 0, triggers at received power levels above -64
dBm that are present in the RF channel you receive on. If the received power is less than -64 dBm,
RDP = 0.
But i think that is not enough for measure the distance!
But has the crazyflie the same tool or is different?? My ambition is have two crazyflies that can comunicate each other and measure their relative distance.
Re: Radio Signal Intensity
I think you could get a rough estimate by transmitting(pinging) with different power settings and test when you get something back.
Code: Select all
SPI RF-SETUP(RF_PWR) RF output power DC current consumption
11 0dBm 11.3mA
10 -6dBm 9.0mA
01 -12dBm 7.5mA
00 -18dBm 7.0mA
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Re: Radio Signal Intensity
Do you mean calculating the time between the trasmission and the reception?? but with this implementation both the device must know the start time of trasmission! it could be a problem!!!
But is possible to have two crazyflie that comunicate each other? Or what kind of sensors can I mount to estimate the distance of a crazyflie from another?
I was thinking to use a camera, but the various implementations use a trasmitter i think it can't trasmit on various channel!!!
The best could be somthing on board but since low payload and little computationa capacity i cant find an adequate sensor!!!!!
But is possible to have two crazyflie that comunicate each other? Or what kind of sensors can I mount to estimate the distance of a crazyflie from another?
I was thinking to use a camera, but the various implementations use a trasmitter i think it can't trasmit on various channel!!!
The best could be somthing on board but since low payload and little computationa capacity i cant find an adequate sensor!!!!!
Re: Radio Signal Intensity
I think you need to be a bit more specific about you requirements. How precise do you need to know the distance, do you need to know the direction etc.
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Re: Radio Signal Intensity
The project is just started so the goals are not so clear For now I'm trying to understand what i can do and what i can't do.
For now the main idea is to have about 10 crazy flie which have to cooperate together!! One easy algorithm to have a stable swarm is to keep constant the relative distance form every robots. But for this, any robots have to know the distance from its neighbors.
Now I hope my goals are a little bit clearer.
Marco
For now the main idea is to have about 10 crazy flie which have to cooperate together!! One easy algorithm to have a stable swarm is to keep constant the relative distance form every robots. But for this, any robots have to know the distance from its neighbors.
Now I hope my goals are a little bit clearer.
Marco
Re: Radio Signal Intensity
That is also one of our dream goals but without advanced position tracking systems such as VICON it is very difficult to accomplice. I'm not yet aware of any research lab that has managed to do it without an external position tracking system. We have used a kinect to do external position tracking and with that it might be possible to control a couple of Crazyflies but I don't think that was your goal or?