Other Parts Discussed in Thread: CC2340R5
Tool/software:
Hello,
I'm using TI's Low Power BLE SDK v8.40.00.61, and I’ve modified the Basic BLE example to function as a central device.
Functionality
-
The central device scans and connects successfully to a BLE peripheral.
-
After connecting, it performs service and characteristic discovery.
-
I can correctly match the required custom service and characteristic UUIDs.
The Issue
Even after discovering the correct characteristic:
-
I attempt to enable notifications by writing
0x0001to the CCCD (Client Characteristic Configuration Descriptor). -
The server never triggers the notification.
-
The client also does not receive any notification event.
-
The CCCD write operation completes successfully, but data flow never starts.
-
- here is the code below how i'm trying to notify after characteristic is discovered
BLEAppUtil_EventHandler_t dataGATTHandler =
{
.handlerType = BLEAPPUTIL_GATT_TYPE,
.pEventHandler = GATT_EventHandler,
.eventMask = BLEAPPUTIL_ATT_FLOW_CTRL_VIOLATED_EVENT |
BLEAPPUTIL_ATT_MTU_UPDATED_EVENT |
BLEAPPUTIL_ATT_READ_BY_GRP_TYPE_RSP |
BLEAPPUTIL_ATT_READ_BY_TYPE_RSP |
GATT_MSG_EVENT |
BLEAPPUTIL_ATT_HANDLE_VALUE_NOTI
};
case ATT_READ_BY_TYPE_RSP:
{
MenuModule_printf(APP_MENU_SCAN_EVENT, 0, "Invoked");
attReadByTypeRsp_t *rsp = &gattMsg->msg.readByTypeRsp;
for (uint8_t i = 0; i < rsp->numPairs; i++)
{
uint8_t *p = rsp->pDataList + i * rsp->len;
uint16_t attrHandle = BUILD_UINT16(p[0], p[1]);
uint8_t properties = p[2];
uint16_t valueHandle = BUILD_UINT16(p[3], p[4]);
if (targetServiceFound &&
p[20] == 44 && p[19] == 28 && p[18] == 151 && p[17] == 113 &&
p[16] == 249 && p[15] == 162 &&
p[14] == 77 && p[13] == 46 &&
p[12] == 138 && p[11] == 200 &&
p[10] == 117 && p[9] == 34 && p[8] == 120 && p[7] == 115 && p[6] == 124 && p[5] == 10)
//MenuModule_printf(APP_MENU_PROFILE_STATUS_LINE, 0, "chars found");
{
if (properties & GATT_PROP_NOTIFY)
{
MenuModule_printf(APP_MENU_PROFILE_STATUS_LINE, 0,"gatt prop");
attWriteReq_t req;
uint8 configData[2] = {1,0};
req.pValue = GATT_bm_alloc(gattMsg->connHandle, ATT_WRITE_REQ, 2, NULL);
req.type.uuid[0] = LO_UINT16(GATT_CLIENT_CHAR_CFG_UUID);
req.type.uuid[1] = HI_UINT16(GATT_CLIENT_CHAR_CFG_UUID);
bStatus_t status = GATT_ReadByTypeReq(gattMsg->connHandle, &req);
if (req.pValue != NULL)
{
MenuModule_printf(APP_MENU_PROFILE_STATUS_LINE, 0, "write val");
req.handle = valueHandle; // CCCD handle
req.len = 2;
memcpy(req.pValue, configData, 2);
req.cmd = FALSE;
req.sig = FALSE;
bStatus_t status =GATT_WriteNoRsp(gattMsg->connHandle, &req);
if(status == SUCCESS)
{
MenuModule_printf(APP_MENU_PROFILE_STATUS_LINE, 0, "Sucess: %d", SUCCESS);
}
else
{
MenuModule_printf(APP_MENU_PROFILE_STATUS_LINE, 0, "fail: %d", SUCCESS);
}
}
}
break;
}
}
break;
}
From the above code it will perform write operation and its success. however i cannot see any trigger in peripheral or central device. i have used a debug statements on peripheral side if notification is triggered by central i see print statements on uart terminal. However i dont see anything. Can you please let me know how can i enable the notifications.
i have also used the TI simpleconnect mobile application to connect and notify it will work fine. however only when i try doing it using above code its not working. it will not even trigger the
i tried to follow the https://github.com/TexasInstruments-Sandbox/ble_examples/blob/simplelink_low_power_f3_sdk-8.40/examples/rtos/LP_EM_CC2340R5/ble5stack/basic_ble_GATT_client/app/app_menu.c. however i was unable to understand why valuehandle was 47 hardcodded to enable notification.
From the above code it will perform write operation and its success. however i cannot see any trigger in peripheral or central device. i have used a debug statements on peripheral side if notification is triggered by central i see print statements on uart terminal. However i dont see anything. Can you please let me know how can i enable the notifications.
i have also used the TI simpleconnect mobile application to connect and notify it will work fine. however only when i try doing it using above code its not working. it will not even trigger the
"ATT_HANDLE_VALUE_NOTI" this event also.
i tried to follow the https://github.com/TexasInstruments-Sandbox/ble_examples/blob/simplelink_low_power_f3_sdk-8.40/examples/rtos/LP_EM_CC2340R5/ble5stack/basic_ble_GATT_client/app/app_menu.c. however i was unable to understand why valuehandle was 47 hardcodded to enable notification.
