Other Parts Discussed in Thread: SYSCONFIG
Hello,
General Information:
SDK: 9.11.0.18
SysConfig:1.25.0
Board: CC2744 R7
Project: Central Role
255 Max MTU size setup in SysConfig
We are running into an issue when attempting to use the function GATT_WriteNoRsp to send a message to a server.
Steps:
1.Call GATT_ExchangeMTU
attExchangeMTUReq_t mtuReq;
mtuReq.clientRxMTU = 251; // Example: request 255 bytes
bStatus_t status = GATT_ExchangeMTU(aData_ptr->ConnHandle_u16, &mtuReq, gSelfEntity);
if (status == SUCCESS) {
__asm("NOP");
}
Results:
a) GATT callbacks are called as such: ATT_EXCHANGE_MTU_RSP first with status SUCCESS and then ATT_MTU_UPDATED_EVENT with status SUCCESS. No further callback with bleProcedureComplete event.
b) We can see the exchange happen over the air. Request: 02 07 03 00 04 00 02 FB 00 70 9D 2B. Response: 0A 07 03 00 04 00 03 FB 00 E1 92 46
c) We can assume that the MTU exchange has happened correctly. The MTU should now be set to the minimum value of the 2, in this case 0xFB, correct?
2. After 5 ms we start a GATT_WriteNoRsp of size 0x3D
Results:
a) GATT_WriteNoRsp returns SUCCESS.
b) No actual transmission happens over the air.
c) If we reduce length to something like 10 bytes then we are able to send a packet -> it makes me think that the MTU is not correctly set.
Please help us with the reason as to why we cannot send packets over the default MTU size.
Thank you!
