CC2640: CC2640 Central Read/Write from the Peripheral.

Anil Dhanawade

Part Number: CC2640

Hi all,

This is Anil. I am working on the CC2640 Central part. In this one i want to check the data which is sent by peripheral by using the characteristics.

Here i am getting the particular peripheral Service UUID, Characteristics handle, Service handle.

Now i need a data which is sent by Peripheral.

Central Code:

static void SimpleBLECentral_processGATTDiscEvent(gattMsgEvent_t *pMsg)
{
static char c=0;
static char j=0;

if (discState == BLE_DISC_STATE_MTU)
{
// MTU size response received, discover simple service
if (pMsg->method == ATT_EXCHANGE_MTU_RSP)
{
uint8_t uuid[ATT_BT_UUID_SIZE] = { LO_UINT16(SIMPLEPROFILE_SERV_UUID),
HI_UINT16(SIMPLEPROFILE_SERV_UUID) };

// Just in case we're using the default MTU size (23 octets)
Display_print1(dispHandle, 4, 0, "MTU Size: %d", ATT_MTU_SIZE);

discState = BLE_DISC_STATE_SVC;

// Discovery simple service
VOID GATT_DiscPrimaryServiceByUUID(connHandle, uuid, ATT_BT_UUID_SIZE,
selfEntity);
memcpy( UUID_TEMP , uuid, 2); // Getting Service UUID Here
}
}
else if (discState == BLE_DISC_STATE_SVC)
{
// Service found, store handles
if (pMsg->method == ATT_FIND_BY_TYPE_VALUE_RSP &&
pMsg->msg.findByTypeValueRsp.numInfo > 0)
{
start = svcStartHdl = ATT_ATTR_HANDLE(pMsg->msg.findByTypeValueRsp.pHandlesInfo, 0); //Service Handle
end = svcEndHdl = ATT_GRP_END_HANDLE(pMsg->msg.findByTypeValueRsp.pHandlesInfo, 0);
}

// If procedure complete
if (((pMsg->method == ATT_FIND_BY_TYPE_VALUE_RSP) &&
(pMsg->hdr.status == bleProcedureComplete)) ||
(pMsg->method == ATT_ERROR_RSP))
{
if (svcStartHdl != 0)
{
attReadByTypeReq_t req;

// Discover characteristic
discState = BLE_DISC_STATE_CHAR;

TEMP[c++] = req.startHandle = svcStartHdl;
TEMP[c++] = req.endHandle = svcEndHdl;
TEMP[c++] = req.type.len = ATT_BT_UUID_SIZE;
// TEMP[3] = req.type.uuid[0] = LO_UINT16(SIMPLEPROFILE_CHAR1_UUID);
// TEMP[4] = req.type.uuid[1] = HI_UINT16(SIMPLEPROFILE_CHAR1_UUID);

TEMP[c++] = req.type.uuid[0] = LO_UINT16(SIMPLEPROFILE_CHAR5_UUID);
TEMP[c++] = req.type.uuid[1] = HI_UINT16(SIMPLEPROFILE_CHAR5_UUID); //Characteristics ID here

VOID GATT_ReadUsingCharUUID(connHandle, &req, selfEntity);

// GATT_ReadCharValue(connHandle, &req, selfEntity);

// memcpy(GAP_DATA,pMsg->msg.readRsp.pValue,pMsg->msg.readRsp.len);

}
}
}
else if (discState == BLE_DISC_STATE_CHAR)
{
// Characteristic found, store handle
if ((pMsg->method == ATT_READ_BY_TYPE_RSP) &&
(pMsg->msg.readByTypeRsp.numPairs > 0))
{
temp[j] = charHdl = BUILD_UINT16(pMsg->msg.readByTypeRsp.pDataList[0],
pMsg->msg.readByTypeRsp.pDataList[1]); //Characteristics Handle

Display_print0(dispHandle, 2, 0, "Simple Svc Found");
procedureInProgress = FALSE;

By this one i am getting all the details whichever i mentioned above. now i am trying to read or write data using CC2640 Central.

How to do it.?

Thanks

Anil D.

over 8 years ago

0 Marie H over 8 years ago

TI__Guru* 83901 points

Hi Anil,

You can use GATT_ReadCharValue() to read the characteristiv value. You can read the full API description in the Software Developer's Guide: http://www.ti.com/lit/swru393

The two main things to remember are to set up the attReadReq correctly, and to make a ATT_READ_RSP event case to catch the read value.

0 Anil Dhanawade over 8 years ago in reply to Marie H

Expert 2760 points

Hi Marie,

if (events & SBC_ATT_READ_EVT)
{
events &= ~SBC_ATT_READ_EVT;
Util_stopClock( &ATT_Read_Clock);

attReadReq_t req;

req.handle = CHAR_HANDLE; // Which handle i found for reading
status = GATT_ReadCharValue(connHandle, &req, selfEntity);
Util_startClock(&ATT_Read_Clock);
}

See this i created the event for reading. and in that one i wrote the function " GATT_ReadCharValue(connHandle, &req, selfEntity); ".
But still i am not getting hits on the "GATT_MSG_EVENT" for checking the "ATT_FIND_INFO_RSP or ATT_ERROR_RSP".

" set up the attReadReq correctly" what is means? After Above mentioned code i started clock for 3 sec.
Is there any wrong in this coding. Please suggest me something.

One more point i need to mention here is that I am not going with KEY pressing. I am going with the Advertising data, If data matched then Establish a link with a particular peripheral.

Thanks.
Anil D.

0 Anil Dhanawade over 8 years ago in reply to Marie H

Expert 2760 points

Hi Marie,

Really thanks for giving the suggestion. i got the data from the peripheral with your solution. I created one event for it and i am able to get the data in the "
if ((pMsg->method == ATT_READ_RSP) ||
((pMsg->method == ATT_ERROR_RSP) &&
(pMsg->msg.errorRsp.reqOpcode == ATT_READ_REQ)))
{
if (pMsg->method == ATT_ERROR_RSP)
{
Display_print1(dispHandle, 4, 0, "Read Error %d", pMsg->msg.errorRsp.errCode);
}
else
{
// After a successful read, display the read value
Display_print1(dispHandle, 4, 0, "Read rsp: %d", pMsg->msg.readRsp.pValue[0]);
memcpy(GAP_DATA,pMsg->msg.readRsp.pValue,pMsg->msg.readRsp.len);
}

"
GAP_DATA i got the result.

thanks .
Anil D.

0 Anil Dhanawade over 8 years ago in reply to Marie H

Expert 2760 points

Hello marie,

i wrote the one more event for Writing data into Peripheral.

Code:

if (events & SBC_ATT_WRITE_EVT)
{
unsigned char *RSSI_Update="#5,5,23-01-2018-16:00:00;";
events &= ~SBC_ATT_WRITE_EVT;
Util_stopClock( &ATT_Write_Clock);

uint8_t status;
// Do a write
attWriteReq_t req;

req.pValue = GATT_bm_alloc(connHandle, ATT_WRITE_REQ, 1, NULL);
if ( req.pValue != NULL )
{
req.handle = 0x0024;
req.len = 25;
req.pValue = RSSI_Update;
req.sig = 0;
req.cmd = 0;

status = GATT_WriteCharValue(connHandle, &req, selfEntity);
if ( status != SUCCESS )
{
GATT_bm_free((gattMsg_t *)&req, ATT_WRITE_REQ);
}
}
else
{
status = bleMemAllocError;
}

is this things are correct?

Thanks

Anil D.

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CC2640: CC2640 Central Read/Write from the Peripheral.