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RSSI always at 0 during scanning

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Total Posts: 13

Joined 2015-01-12

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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:
{0x040x42CHANNEL_SCAN0x400x000x01}// Assign channel: Receive Only Channel, Background Scanning Enable
{0x050x51CHANNEL_SCAN0x000x000x000x00}// Set channel ID
{0x020x63CHANNEL_SCAN0xFF}// Channel Low Priority Search Timeout: infinite
{0x020x44CHANNEL_SCAN0x00}// Channel Search Timeout: disable
{0x020x45CHANNEL_SCAN0x39}// Set Channel RF Frequency, 2457 MHz
{0x010x4BCHANNEL_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.      
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RankRankRankRank

Total Posts: 719

Joined 2012-09-14

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Hi,

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

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 ?      
Rank

Total Posts: 13

Joined 2015-01-12

PM

Hello,

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

Total Posts: 719

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.
     
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Total Posts: 13

Joined 2015-01-12

PM

Hello,

Yes, i use the command: 0x02, 0x6E, 0x00, 0xC0
The ANT version is: BAW4.01B00      
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Total Posts: 719

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]      
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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: 286)
  • ko.txt (File Size: 3KB - Downloads: 344)
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Total Posts: 719

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.