RSSI always at 0 during scanning

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19 August 2015 07:54 AM

Nicolas Newbie

Total Posts: 13

Joined 2015-01-12

Hello,

I'm using a N550 with ANT version BAW4.01B00.
When i open a background scanning channel with extended message 0xC0. The measurement type is at 0x20 but the RSSI value is always at 0

scan channel parameters used:

{0x04, 0x42, CHANNEL_SCAN, 0x40, 0x00, 0x01}, // Assign channel: Receive Only Channel, Background Scanning Enable
{0x05, 0x51, CHANNEL_SCAN, 0x00, 0x00, 0x00, 0x00}, // Set channel ID
{0x02, 0x63, CHANNEL_SCAN, 0xFF}, // Channel Low Priority Search Timeout: infinite
{0x02, 0x44, CHANNEL_SCAN, 0x00}, // Channel Search Timeout: disable
{0x02, 0x45, CHANNEL_SCAN, 0x39}, // Set Channel RF Frequency, 2457 MHz
{0x01, 0x4B, CHANNEL_SCAN}, // Open channel 

When i open a normal channel, the RSSI is correctly received.

Any idea where is the problem coming from ?

Thanks for your help.

24 August 2015 05:00 PM #1

Harrison Administrator

Total Posts: 745

Joined 2012-09-14

PM

Hi,

Do you still see the same issue on V5.00 of the SoftDevice?

25 August 2015 08:01 AM #2

Nicolas Newbie

Total Posts: 13

Joined 2015-01-12

PM

Hello,

I don't know which softdevice version i have, i still have the original firmware. Is there a command for knowing the softdevice version ?

12 January 2016 07:06 AM #3

Nicolas Newbie

Total Posts: 13

Joined 2015-01-12

PM

Hello,

I would be very grateful if someone can answer my question.

01 February 2016 09:56 AM #4

Harrison Administrator

Total Posts: 745

Joined 2012-09-14

PM

Hi Nicolas,

Did you use the lib config (0x6E) command to enable RSSI measurement?
To find your SoftDevice version, you may issue a request message (0x4D) for the ANT version message (0x3E), which will output a version string.

01 February 2016 10:16 AM #5

Nicolas Newbie

Total Posts: 13

Joined 2015-01-12

PM

Hello,

Yes, i use the command: 0x02, 0x6E, 0x00, 0xC0
The ANT version is: BAW4.01B00

01 February 2016 10:58 AM #6

Harrison Administrator

Total Posts: 745

Joined 2012-09-14

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Could you post a log of your received message packets? For instance, I am using ANTware II to run a background scan on an N550 module and I am receiving the following packets:

Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-4B-C0-21-00-01-01-20-C5-B0
Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-58-C0-21-00-01-01-20-C4-B0
Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-65-C0-21-00-01-01-20-C4-B0
Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-72-C0-21-00-01-01-20-C5-B0
Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-7F-C0-21-00-01-01-20-C5-B0
Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-80-C0-21-00-01-01-20-C5-B0
Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-8C-C0-21-00-01-01-20-C5-B0
Received BROADCAST_DATA_0x4E
:: 4e, 00-00-00-00-00-00-00-00-8D-C0-21-00-01-01-20-C5-B0

In this case the RSSI is represented by the second last message byte, and is changing slightly between -59 and -60 dBm.

Or as received over the USB UART interface directly:
662.910 { 144706433} Rx - [A4][11][4E][00][00][00][00][00][00][00][00][D0][C0][21][00][01][01][20][C5][B0][9F]

04 February 2016 05:29 AM #7

Nicolas Newbie

Total Posts: 13

Joined 2015-01-12

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I have done more testing and it only happens when there is another channel open.
I have attached files with log of the two cases:
ok.txt: there is only 1 scan channel, the RSSI is correct
ko.txt: there is another open channel, the RSSI is always at 0

File Attachments

ok.txt (File Size: 2KB - Downloads: 808)
ko.txt (File Size: 3KB - Downloads: 883)

04 March 2016 11:32 AM #8

Harrison Administrator

Total Posts: 745

Joined 2012-09-14

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Hi,

Thank you for your patience. This is a bug in the firmware, we plan to fix it in a future maintenance release of the SoftDevice. In the meantime, you can fix this issue by opening the background scanning channel first, and not opening the slave channel beforehand.

ANT Forum

RSSI always at 0 during scanning

File Attachments