Ignoring acks as an strategy to extending radio reach?

Firmware/software/electronics/mechanics
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hsanjuan
Beginner
Posts: 19
Joined: Sat Jul 20, 2013 10:51 am

Ignoring acks as an strategy to extending radio reach?

Post by hsanjuan »

Hello,

I have been wondering... currently in the client, the presence of the radio link is determined by the number of packets without response. The crazyradio would send a packet and expect an ack. If that does not happen, Crazyradio will retry up to 10 times. If crazyradio fails to obtain an ack, the radio driver from the Crazyflie client can and will still retry by sending more packets (I think the default is set to 10). Depending on the radio retry count, we determine the link quality. If the client retries too many times without success, we determine the link is down and disconnect.

My question is: if we have a powerful radio transmitter (i.e. a Crazyradio with a big antenna, or the PA model with 1km range...), assuming the packets will always reach the Crazyflie, will the Crazyflie acks be able to reach back to the Crazyradio? In this context, would it make sense to have a mode that just ignore that acks are missing and keep transmitting like nothing?
marcus
Bitcraze
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Re: Ignoring acks as an strategy to extending radio reach?

Post by marcus »

Hi,

Yes, it would be possible to disable the ACK checking and have a mode where the "downlink" is lost, but maybe not the uplink. This would enable the user to still pilot the Crazyflie with the client (instead of just killing the link) when you get out of range. But the firmware in the Crazyflie will cut the motors if there's no control packets received for 2 seconds (it might also be 1 second).
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