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JiZh_4619191
Level 4
Level 4
25 replies posted 25 sign-ins 10 replies posted

Hi cypress,

Since CYW20719 supports DLE ( data length extension ), how could I send a large number of data? Is there an API in CYW20719 SDK for this purpose?

Thanks

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1 Solution
Charles_Lai
Moderator
Moderator
Moderator
250 replies posted 100 solutions authored 100 replies posted

Hi,

Sorry but I got different view on this issue.

I think the max_mtu_size in wiced_bt_cfg.c is to change the size of the ATT packet in upper layer. But DLE is a feature provide by Link Layer and is meant to enlarge the Data Channel PDU. So changing max_mtu_size in wiced_bt_cfg.c won't be able to do this.

Fortunately there do exist some flags related to DLE. File '/20719-B1_Bluetooth/include/20719/stack/hcidefs.h' contains the "LE features encoding" settings and in this file you will find the following lines:

pastedImage_0.png

I think this are the flags controlling whether to enable DLE or not. But where to set the exact PDU payload size is questionable to me for now (May it be auto determined in the negotiation?).

This is the information I think would be helpful:

<<<<<<<<<<<<<>>>>>>>>>>>>>

Best Regards

C. L.

<<<<<<<<<<<<<>>>>>>>>>>>>>

View solution in original post

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2 Replies
SheetalJ
Moderator
Moderator
Moderator
750 replies posted 500 likes received 500 replies posted

Hi JiZh_4619191​,

The maximum payload depends on the MTU size. You can set this size in application wiced_bt_cfg.c file using attribute max_mtu_size.

Charles_Lai
Moderator
Moderator
Moderator
250 replies posted 100 solutions authored 100 replies posted

Hi,

Sorry but I got different view on this issue.

I think the max_mtu_size in wiced_bt_cfg.c is to change the size of the ATT packet in upper layer. But DLE is a feature provide by Link Layer and is meant to enlarge the Data Channel PDU. So changing max_mtu_size in wiced_bt_cfg.c won't be able to do this.

Fortunately there do exist some flags related to DLE. File '/20719-B1_Bluetooth/include/20719/stack/hcidefs.h' contains the "LE features encoding" settings and in this file you will find the following lines:

pastedImage_0.png

I think this are the flags controlling whether to enable DLE or not. But where to set the exact PDU payload size is questionable to me for now (May it be auto determined in the negotiation?).

This is the information I think would be helpful:

<<<<<<<<<<<<<>>>>>>>>>>>>>

Best Regards

C. L.

<<<<<<<<<<<<<>>>>>>>>>>>>>

0 Likes