CC2640R2F: Unable to increase PDU size in BLE stack

Gerrit Dijkstra

Part Number: CC2640R2F

Hello,

I have difficulties increasing the PDU size to 250.

My environment:
SDK:                       simplelink_cc2640r2_sdk_1_50_00_58
HW:                       LAUNCHXL-CC2640R2
Project:                based on simple_peripheral_cc2640r2lp_app.

At this moment I have an effective PDU size of 20 bytes.

I followed the instructions as mentioned in the header “ble_user_config.h”

When looking into the memory, I see that the bleStackConfig has been changed (maxPduSize = 0xFA)

Upon sending a databuffer with size 40 by “GATT_Notification()”, this function returns 0x1b as status.
NOTE: Sending databuffers with a size up to 20 bytes is working OK.

Q: What did I miss, how can I get this working?

Regards,
Gerrit

over 7 years ago

0 Madhusudhan K over 7 years ago

Expert 1815 points

Hi,
Try adding the following code in SimpleBLEPeripheral_init()

uint8_t maxpayload = 14;
GATTServApp_SetParameter(GATT_PARAM_NUM_PREPARE_WRITES,sizeof(uint8_t),&maxpayload);

also change the MAX_PDU_SIZE in “ble_user_config.h” to 255

0 Gerrit Dijkstra over 7 years ago in reply to Madhusudhan K

Prodigy 120 points

Hi, when I do this, the code runs into an assert on a HARDWARE_ERROR in the function SimpleBLEPeripheral_processStackMsg(ICall_Hdr *pMsg);

0 Eirik V over 7 years ago in reply to Gerrit Dijkstra

TI__Guru 56590 points

Hello Gerrit,
0x1B means bleInvalidMtuSize (Packet length is larger than connection's MTU size). A client device can request a larger ATT_MTU during a connection by using the GATT_ExchangeMTU() command. Please refer to the "Configuring for Larger MTU Values" in the CC2640R2F SDG.

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CC2640R2F: Unable to increase PDU size in BLE stack