regarding the distance for the bluetooth range for scan and advertisement for nrf52840

[liuluan1984]

Hi Nordic,

I am using the two nrf52840 units to test adv and scanning in a pair for the development. I am using BLE_GAP_PHY_CODED for both scan and advertisement. But when I test it, seems the package lost get very high when distance is longer than 70 meters. Any way to improve it? Also, is it possible to use the antenna signal amplifer for improve the receiving and advertisement distance?

[Simonr]

Hi

I'm sorry, but why exactly are you only advertising on channel 37? 

There are a few parameters you're missing in order to advertise on the Coded PHY correctly. First off, set the init.advdata.flags is set to BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE in the advertising module.

You can check out the example uploaded by Vidar in this case which should have a peripheral and central example that advertises and connects using the Nordic UART service over Coded PHY.

Best regards,

Simon

[liuluan1984]

Hi,

I have applied what you suggested, but still communication range is very short.  

The purpose for using channel 37 is to advertise the data in the channel for the multipule remote receivers at the same time. 

Here is my advertisement code 

The scanning code I keep same as the early comments. 

[awneil]

liuluan1984 said:

The purpose for using channel 37 is to advertise the data in the channel for the multipule remote receivers at the same time

But how does using a single channel - as opposed to the normal three - help that ?

The whole point of advertising is that it's a broadcast that can been "seen" by all receivers, and the whole point of having 3 channels is to make it more likely that the broadcasts will be seen!

EDIT:

"If any single advertising channel is blocked, the other channels are likely to be free since they’re separated by quite a few MHz of bandwidth"

https://www.argenox.com/library/bluetooth-low-energy/ble-advertising-primer

[liuluan1984]

Yes I know that. But normally it will not always be blocked for one channel for advertisement in our application. So that we want to make one channel advertisement and scanning works for the long range application(400meters)

[awneil]

Still doesn't explain why you don't just do it the normal way - with all three channels?