CTE Length nrf52833

[prosper]

The BLE specification says that the CTE can be a maximum of 160us long. I am trying to set CTE length to 160us, but every time i try to do so, firstly the transmitter stops transmitting for a DFE_DURATION value greater than 10 which is (10*8)=80us. The receiver likewise, code hangs if i try to extend CTE or number of 8us to 20. I can only get it up to 12 which is 96us. Am i doing something wrong, or is there an implementation issue that stops me from being able to do 20 sets of 8u for the CTE?

[Dmitry]

Hi,

Could you share your code here?

prosper said:

firstly the transmitter stops transmitting for a DFE_DURATION value greater than 10 which is (10*8)=80us.

Are you receiving PHYEND event after 80us, or it doesn't transmit at all with that settings?

prosper said:

The receiver likewise, code hangs if i try to extend CTE or number of 8us to 20

Also, what's happening after 96us - the receiver just stops, or hardfault? Did you allocate an array and configure MAXCNT to hold all the samples taken?

[prosper]

For the transmitter, i am using nrfConnect to confirm that its advertising as AOA Beacon. When i set  DFE DURATION greater than 12, the scanner will see the mac address of the device but its name is Unknown. I assume the packet gets big so that ble 4.2 scanner cannot recognize it.

For the receiver, when i set more than 10 8us slots, the code hangs in main, on a line where its waiting for a packet from the radio. Its exactly what happens when the transmitter is not transmitting and the locator is waiting for packets. 

[Dmitry]

prosper said:

or the transmitter, i am using nrfConnect to confirm that its advertising as AOA Beacon. When i set  DFE DURATION greater than 12, the scanner will see the mac address of the device but its name is Unknown.

Are you trying to append CTE to a regular advertising packet? This won't work as you're expecting - the master tries to query your device with scan request, but device cannot answer because it's still transmitting CTE. According to 5.1 spec, CTE packet can be appended only to extended advertising packets.

prosper said:

For the receiver, when i set more than 10 8us slots, the code hangs in main, on a line where its waiting for a packet from the radio.

It's hard to say anything without looking at code...

[Sigurd]

Hi prosper,

If you are experiencing this issue with any kind of Direction finding software evaluation package sent to you by Nordic Semiconductor, then I think this(max value is 10) has been a limitation in older versions. Please create a new private ticket here at Devzone were you request the latest version.