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AIROC™ Bluetooth Forum Discussions

aglier
Level 4
Level 4
25 replies posted 25 sign-ins 10 replies posted

Hi,

 

I'm trying to establish a stable gap connection by using a terminal interface.

After successful connecting to a device I get a disconnect event after a few seconds (2-4 seconds)

I recognized, that the connect event was holding a supervision timeout of 0x02BC which would be above the maximum that is described in the documentation. Can this be the cause for the disconnect?

I was expecting, that the connection will last until I actively disconnect, is that a wrong assumption?

I will post my terminal output here, thanks in advance:

 

/rfac<\r><\n>
@R,000B,/RFAC,0000<\r><\n>
@E,0005,RFAC<\r><\n>
@E,003B,BOOT,E=01021D1D,S=05020016,P=0103,H=D1,C=00,A=F5E33648797D<\r><\n>
@E,000E,ASC,S=01,R=03<\r><\n>
/C,A=008025d15fa3<\r><\n>
@R,000D,/C,0000,C=00<\r><\n>
@E,000E,ASC,S=00,R=03<\r><\n>
@E,0035,C,C=01,A=008025D15FA3,T=00,I=0028,L=0000,O=02BC,B=00<\r><\n>
@E,0010,DIS,C=01,R=0908<\r><\n>
@E,000E,ASC,S=01,R=03<\r><\n>

 

 

Best regards

Alex

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1 Solution

I finally solved the issue.

The peripheral device was BT 5.0 based an therefor supporting LE 2M PHY.

The default behavior is that it prevers 2M Phy connections:

"A PHY Update Procedure is started after a new connection is established.
The preferred PHY is set to “LE 2M” for both directions."

If I change this setting to use 1M PHY only, everything is working as expected.

Other devices such as 4.2 based smartphones or other bluetooth chips were able to connect to the device with default settings.

Is there a known issue regarding the negotiation between 1M and 2M PHY?

 

Best regards

Alex

View solution in original post

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7 Replies
BragadeeshV
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

Hi @aglier 

Please let us know which bluetooth product you are using?  Which is the host device controlling the Bluetooth controller?

Regards,
Bragadeesh
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aglier
Level 4
Level 4
25 replies posted 25 sign-ins 10 replies posted

Hi,

 

I'm using the CYBT-343026-EVAL 02 eva board.

The module on this eva board is CYBT-343026-01

The boot command returns: @E,003B,BOOT,E=01021D1D,S=05020016,P=0103,H=D1,C=00,A=FB8A576F14EC

The host device is a windows computer that connects to the board via FTDI to the peripheral uart.

 

Best regards

Alex

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BragadeeshV
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

Hi @aglier , 

Can you please let us know the peer device you are using. Also, I don't understand the logs you have sent me. Can you please send us the HCI logs of the transaction  happening (with timestamp) between the host PC and the BT controller to debug the issue?

Regards,
Bragadeesh
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Hi @BragadeeshV ,

maybe I did not make this clear enough:

I'm interfacing the CYBT-343026-EVAL 02 eva board via Uart (peripheral uart over ftdi to PC) and using the EZSerial commands to set up a connection.

The logs that I send you, was copied from a terminal program that was sending text commands (EZSerial commands) and receiving the appropriate response.

As I'm not interfacing the HCI uart , I can not send you any logs.

 

Best regards

Alex

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BragadeeshV
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

Hi @aglier ,

Please check the troubleshooting section from the app note EZ-Serial WICED Firmware Platform User Guide for CYW2070x-based Modules. Also look at the operational examples: GAP Peripheral Examples 

https://www.cypress.com/file/452971/download

 

Regards,
Bragadeesh
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I finally solved the issue.

The peripheral device was BT 5.0 based an therefor supporting LE 2M PHY.

The default behavior is that it prevers 2M Phy connections:

"A PHY Update Procedure is started after a new connection is established.
The preferred PHY is set to “LE 2M” for both directions."

If I change this setting to use 1M PHY only, everything is working as expected.

Other devices such as 4.2 based smartphones or other bluetooth chips were able to connect to the device with default settings.

Is there a known issue regarding the negotiation between 1M and 2M PHY?

 

Best regards

Alex

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aglier
Level 4
Level 4
25 replies posted 25 sign-ins 10 replies posted

Hi @BragadeeshV ,

I'm running the CYW2070x based module in GAP central mode.

I'm trying to connect to another device that uses the Telit Bluemod S50 module.

This module advertised a custom service that I'm looking for.

However, when I'm trying to connect without any further action, I will be disconnected after exactly 7.35 seconds.

The output that I sendet you was taken from a serial terminal that is running on my machine.

The disconnect reports an error code of 0908 EZS_ERR_SPEC_CONNECTION_TIMEOUT Connection Timeout.

So I'm wondering what can cause this disconnect and what is running inside the Cypress EZ Serial firmware that might throw this disconnect event.

Is there a way to get closer in contact or arrange a meeting to further tackle the issue?

 

Best regards

Alex

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