CC2340R5: Central mode without button option CC2340R5

Hello Surya,

I would suggest to take a look at the following central example: https://github.com/TexasInstruments-Sandbox/ble_examples/tree/simplelink_low_power_f3_sdk-7.40.03/examples/rtos/LP_EM_CC2340R5/ble5stack/basic_ble_GATT_client

1. The menu/button interaction are defined in the app_menu.c. If you dont want to use the display, you can disable it in SysConfig under BLE -> Advance Settings -> Disable Display Module.
2. If you want to start scanning on power-up, then all of the functions executed inside Central_start() function (look inside app_central.c) must be executed.
3. Please look into: https://software-dl.ti.com/simplelink/esd/simplelink_lowpower_f3_sdk/9.11.00.18/exports/docs/ble5stack/ble_user_guide/html/ble-stack-5.x/gapbondmngr-cc23xx.html?highlight=passkey#passcode-entry
4. The advertising data and characteristic data are read at different moments of the process (adv and connection). The first one is read from the adv report, while the second one relies on the gatt table of the server and gatt operations executed to the corresponding handles. Please take a look at these two training material:
   1. Adv Report: https://dev.ti.com/tirex/explore/content/simplelink_academy_for_cc23xx_8_40_01_00/_build_simplelink_academy_for_cc23xx_8_40_01_00/source/ble/cc2340rx_02_ble_scan_adv_basic.html
   2. Gatt: https://dev.ti.com/tirex/explore/content/simplelink_academy_for_cc23xx_8_40_01_00/_build_simplelink_academy_for_cc23xx_8_40_01_00/source/ble/cc2340rx_01_basic_examples_advanced.html

BR,

David.

Dear David 
Thanks for the suggestions, now i have changed the device cc2340 into cc1352

• Code Composer Studio: 20.2.0

• SDK: simplelink_cc13xx_cc26xx_sdk_8_30_01_01

• Example project: simple_central_CC1352R1_LAUNCHXL_tirtos7_ticlang

Requirements

• Automatically connect to a CC2340R5-based instrument using a predefined static address and passkey.

• Receive data from the instrument.

• Print the received data via UART.

• The instrument advertises once every minute and stays in advertising mode for 20 seconds. The scanner must detect and connect during this window.

Progress So Far

I’ve configured the CC1352R-based device to scan without requiring button input. When scanning, the UART prints the device names. If the known BLE address is detected, scanning stops and an automatic connection is initiated.

Example UART output (captured in HERCULES, with modified Display_printf):

Current Roadblock

At this point, the device connects successfully and encryption is completed. Now I need to:

• Read and write data to/from the connected instrument.

• Possibly access or interpret advertising data (if available after connection).

Request

Could you please guide me on how to proceed with:

1. Writing data to the connected BLE device.

2. Receiving data notifications or indications.

3. Handling GATT read/write operations post connection.

4. (Optional) Accessing any remaining advertisement data after the connection is established, if possible.

Any code references, TI examples, or pointers to API functions would be greatly appreciated.

Regards
Surya.

Hello Surya,

I think the best example for this is the one I am sharing: https://github.com/TexasInstruments-Sandbox/ble_examples/tree/simplelink_cc13x2_26x2_sdk-5.10/examples/rtos/CC26X2R1_LAUNCHXL/ble5apps/simple_serial_socket_client. There you have notifications and write commands.

Please use it as a reference and let me know if you have questions in the process.

Best Regards,

David.

Hello David ,

Thanks for the reference link. However, the SDK example you shared is quite old and still relies on button-based operations. As I mentioned earlier, I'm specifically trying to eliminate the need for button interactions. I want the process — including scanning, connecting, writing, and reading — to be fully automatic.

So far, I've successfully implemented auto-scanning and can find the known device using its static address. The device connects successfully, and the process reaches the "encryption success" stage, but it then gets stuck there.

I'm seeking your advice on which API I should call next, or what steps I need to take to proceed with writing to and reading from the connected device. Could you please guide me on how to achieve this using the current SDK?

If needed, I’m happy to share my complete code for your review.

regards
Surya

 Dear David ,
currently the code execte the following function then stuck in this 

Hello Surya,

I assume you get a Encryption success print message correct? Does it get stuck when running SimpleCentral_autoConnect();? I would refer to the simple_central example for the configuration of the autoconnection feature. Specifically SimpleCentral_autoConnect() and SimpleCentral_doAutoConnect() in simple_central.c. Note that the central won't start automatically connecting to the chosen group until all defined group members are successfully scanned and found. Number of group members are defined by MAX_NUM_BLE_CONNS. Hence the user have to pre-define the number of members that wanted to be connected to.

BR,

David.

Hello David 

Please review the following log and let me know what steps I need to take next:

*Simple Central
< Next Item
+Set Scanning PHY >
Discover Devices
+Set AutoConnect

*Simple Central
Stop Discovering >

Discovering...

DEFAULT_Discovered: 0x40791213A330:0x40791213A330

FM_IDENTIFIED

DEFAULT_Discovered: 0x40791213A330:0x40791213A330

FM_IDENTIFIED

Connecting to FM_ADDR...
Connected to 0x40791213A330
Num Conns: 1

*Simple Central
< Next Item
+Set Scanning PHY >
Discover Devices
+Work with
+Set AutoConnect

Encryption success

Notes:

1. Automatic Scan - Completed

   The scan was automatically started and completed from the SimpleCentral_init function using:

   GapScan_enable(0, 0, 0)

2. Device Discovery - Completed

   The known device was discovered using the following logic (when DEFAULT_DEV_DISC_BY_SVC_UUID is not defined):

   char bdAddrStr[18]; // 17 characters + null terminator
snprintf(bdAddrStr, sizeof(bdAddrStr), "%s", Util_convertBdAddr2Str(pAdvRpt->addr));
Display_printf(dispHandle, 0, 0, "DEFAULT_Discovered: %s:%s\r\n", Util_convertBdAddr2Str(pAdvRpt->addr), bdAddrStr);

if (strcmp(bdAddrStr, FM_ADDR) == 0)
{
GapScan_disable(0);
FM_FOUND = TRUE;
Display_printf(dispHandle, 0, 0, "\r\nFM_IDENTIFIED\r\n"); // Store for later connection
memcpy(knownPeerAddr, pAdvRpt->addr, B_ADDR_LEN);
knownPeerAddrType = pAdvRpt->addrType; knownPeerFound = true;
}
   
   
   

3. Connection Request Sent

   After scan is disabled (in SC_EVT_SCAN_DISABLED case), the following logic is executed:

   if (knownPeerFound) { knownPeerFound = false; // Force pairing and bonding mode
uint8_t pairMode = GAPBOND_PAIRING_MODE_INITIATE;
GAPBondMgr_SetParameter(GAPBOND_PAIRING_MODE, sizeof(uint8_t), &pairMode);
uint8_t bondingEnabled = TRUE;
GAPBondMgr_SetParameter(GAPBOND_BONDING_ENABLED, sizeof(uint8_t), &bondingEnabled);
status_t status = GapInit_connect( knownPeerAddrType & MASK_ADDRTYPE_ID, knownPeerAddr, DEFAULT_INIT_PHY, CONNECTION_TIMEOUT );
if (status == SUCCESS)
{
Display_printf(dispHandle, 0, 0, "Connecting to FM_ADDR...");
}
else
{
Display_printf(dispHandle, 0, 0, "Connect failed");
}
return; // Skip the rest of SC_EVT_SCAN_DISABLED
}

4. Link Established

   Once connected (in GAP_LINK_ESTABLISHED_EVENT), the following is logged:

   pStrAddr = (uint8_t*) Util_convertBdAddr2Str(connList[connIndex].addr);
Display_printf(dispHandle, 0, 0, "Connected to %s\r\n", pStrAddr);
Display_printf(dispHandle, 0, 0, "Num Conns: %d\r\n", numConn);



5. Pairing State Handling

   In the SimpleCentral_processPairState function, the following is executed when encryption is successful:

   else if (state == GAPBOND_PAIRING_STATE_ENCRYPTED)
{
if (status == SUCCESS)
{
Display_printf(dispHandle, 0, 0, "Encryption success\r\n");
//SimpleCentral_autoConnect(); // Optional
}
else
{
Display_printf(dispHandle, 0, 0, "Encryption failed: %d\r\n", status);
}
GAPBondMgr_GetParameter(GAPBOND_PAIRING_MODE, &pairMode);
if ((autoConnect) && (pairMode == GAPBOND_PAIRING_MODE_INITIATE))
{
SimpleCentral_autoConnect();
}
}

6. Question: What do I need to do next?


Hello David 
i have comment the below line then i got following logs