No Improvement of BLT 5 Long Range Mode

RE: No Improvement of BLT 5 Long Range Mode

Simonr — Wed, 25 Sep 2019 09:09:03 GMT

1. Both SCANNABLE and NONSCANNABLE should be usable.

2. Great, I just had to confirm it.

3 & 4. Initially, I thought not, but it might be that both scan_phys and the primary_phy must be set to PHY_CODED. I can't confirm this with certainty though as both of our "long-range gurus" are out of the office this week. I'll be able to provide a definite answer early next week (maybe earlier if I'm able to reach either of them). In the meantime, I urge you to experiment with this, setting either or both of these parameters to CODED.

Best regards and sorry I can't be of more help,

Simon

RE: No Improvement of BLT 5 Long Range Mode

BK — Tue, 24 Sep 2019 14:12:40 GMT

Hi Simon, sorry that's my mistake.

(1)Actually I mean it's BLE_GAP_ADV_TYPE_EXTENDED_CONNECTABLE_NONSCANNABLE_UNDIRECTED in Demo whereas my application is BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED.

(2)And yes, my advertising flag is set to be BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE.

(3)Is that OK to set primary channel to 1MBPS and secondary channel to CODED for long range mode for the peripheral? Or they both have to be set to CODED?

(4)Is that OK to set scan_phys to BLE_GAP_PHY_AUTO for long range mode for the central? Or it has to be set to BLE_GAP_PHY_CODED?

RE: No Improvement of BLT 5 Long Range Mode

Simonr — Tue, 24 Sep 2019 12:48:50 GMT

[quote user="bobokang_2003"]The demo has the setting which is p_advertising->adv_params.properties.type = BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED when the channel is CODED_PHY, while my case is BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED[/quote]

I think you wrote the same thing twice here. What is the ADV_TYPE in your application?

What is your advertising flag set as? This needs to be BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE for the peripheral to work in long-range mode.

For the application to connect when primary PHY is set to CODED_PHY both the peripheral and central must have the same primary PHY. There could be a number of issues in your application(s), but I can't see what it is from the snippets you've uploaded. I also ought to link to this case, as this range issue was caused by a combination of a bad antenna and a less than optimal testing environment.

Best regards,

Simon

RE: No Improvement of BLT 5 Long Range Mode

BK — Tue, 24 Sep 2019 08:49:29 GMT

Hi Simonr, I've checked the source code of BLE long-range demo you mentioned above. I had some findings:

(1)The SDK of demo is 15.0 while my project uses 15.2, therefore a lot of definition of API is different.

(2)The demo has the setting which is p_advertising->adv_params.properties.type = BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED when the channel is CODED_PHY, while my case is BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED

(3) In Demo, adv_params.primary_phy = BLE_GAP_PHY_CODED, while my current setting is adv_params.primary_phy = BLE_GAP_PHY_1MBPS.

So, I changed the adv_params.primary_phy from 1MBPS to CODED. However, after implementing the change, they cannot establish the connection normally.

Do you have any suggestion how to find the root cause of this? (I mean the cause of cannot connect to each other, and, and distance improvement is not obvious)

RE: No Improvement of BLT 5 Long Range Mode

Simonr — Mon, 23 Sep 2019 13:11:20 GMT

Please use the nRF52 BLE Long-range demo on Github as a reference when setting up CODED_PHY and BLE long-range. You can also check out this thread, which clarifies a lot of common errors when setting up a long-range connection.

Best regards,

Simon

RE: No Improvement of BLT 5 Long Range Mode

BK — Mon, 23 Sep 2019 03:17:41 GMT

the first figure is missing, so I attach it again here: