Bluetooth Sample Application - Testing Guide
This guide provides step-by-step instructions for testing Bluetooth functionality on the Astra MCU SDK platform.
Overview
The BT sample application demonstrates Bluetooth Low Energy (BLE) functionality including:
Bluetooth stack initialization
GATT server operations
BLE advertising
Device discovery and connection
GATT read/write operations
Build Instructions
Prerequisites
Hardware Requirements
Astra MCU SDK development board with BT capability
Smartphone or tablet with BLE support
USB cable for firmware flashing and console access
Software Requirements
BLE scanner app on smartphone (recommended apps below)
Serial terminal for console commands
Recommended BLE Apps
Android: nRF Connect for Mobile, BLE Scanner
Configuration and Build Steps
⚠️ Important: Memory Configuration
Before building the application, you must increase the heap size to accommodate the Bluetooth stack requirements.
Required Changes:
Update Linker Script -
soc/SR110/cm55/config/sr110_cm55_hw_gcc_arm.ld:__VM0_HEAP_SIZE = 0x00019000; /* Increase to 100 KiB */
Update Region Definitions -
soc/SR110/cm55/include/region_defs.h:#define VM0_HEAP_SIZE (0x00019000) /* 100 KiB */
💡 Note: The Bluetooth stack requires additional heap memory for proper operation. Without this configuration change, the application may fail to initialize or experience runtime issues.
Binary builds can be generated using either of the following methods:
1. Using Astra MCU SDK VS Code extension
Navigate to IMPORTED REPOS → Build and Deploy in the Astra MCU SDK VS Code Extension.
Select the Build Configurations checkbox, then select the necessary options.
Select bt_sample_app in the Application dropdown. This will apply the defconfig.
Select the appropriate build and clean options from the checkboxes. Then click Run. This will build the SDK generating the required
.elfor.axffiles for deployment using the installed package.
For detailed steps refer to the Astra MCU SDK VS Code Extension Userguide .
2. Native build in the terminal
Select Default Configuration and build sdk + example This will apply the defconfig, then build and install the SDK package, generating the required
.elfor.axffiles for deployment using the installed package.make cm55_bt_sample_app_defconfig BOARD=SR110_RDK BUILD=SRSDK
Rebuild the Application using pre-built package The build process will produce the necessary .elf or .axf files for deployment with the installed package.
make cm55_bt_sample_app_defconfig BOARD=SR110_RDK or make
Note: We need to have the pre-built Astra MCU SDK package before triggering the example alone build.
Deployment and Execution
Setup and Flashing
Open the Astra MCU SDK VSCode Extension and connect to the Debug IC USB port on the Astra Machina Micro Kit. For detailed steps refer to the Astra MCU SDK User Guide .
Generate Binary Files
FW Binary generation
Navigate to IMPORTED REPOS → Build and Deploy in Astra MCU SDK VSCode Extension.
Select the Image Conversion option, browse and select the required .axf or .elf file. If the usecase is built using the VS Code extension, the file path will be automatically populated.
Click Run to create the binary files.
Refer to Astra MCU SDK VSCode Extension User Guide for more detailed instructions.
Model Binary generation (to place the Model in Flash)
To generate
.binfile for TFLite models, please refer to the Vela compilation guide .
Flash the Application
To flash the application:
Select the Image Flashing option in the Build and Deploy view in the Astra MCU SDK VSCode Extension.
Select SWD/JTAG as the Interface.
Choose the respective image bins and click Run.
Refer to the Astra MCU SDK VSCode Extension User Guide for detailed instructions on flashing.
Device Reset
Reset the target device
Running the Application
Identify the COM Port Connect an external USB-to-UART adapter/dongle to your PC, then use the Device Manager to locate the assigned COM port.
Open UART1 COMPORT in Teraterm Using the COM port identified in Step 1, open TeraTerm (or any serial terminal) and connect through that port while attaching the USB-to-UART adapter to the UART1 pins as shown.
Before running the application, make sure to connect a USB cable to the Application SR110 USB port on the Astra Machina Micro board and then press the reset button
Connect to the newly enumerated COM port
The BT sample application logs will then appear in the UART1 logger window.
Testing Procedure
Once the firmware has been built and flashed, you can verify BT functionality using the following steps:
Step 1: Enable Bluetooth
Connect to the device console (UART1) via serial terminal using an external USB to UART adapter.
Execute the following command to enable the Bluetooth stack:
synabt enable
Step 2: Start GATT Server
Start the GATT (Generic Attribute Profile) server:
synabt gatt_server_start
Step 3: Start BLE Advertising
Begin BLE advertising to make the device discoverable:
synabt ble_start_adv
Step 4: Device Discovery and Connection
On your smartphone:
Open your BLE scanner app
Start scanning for BLE devices
Look for a device named “BTA_Amz”
Tap on the device to connect
Step 5: GATT Operations Testing
Once connected, you can test GATT read/write operations:
Read Operations
In your BLE app, navigate to the GATT services
Select a readable characteristic
Perform a read operation
Verify data is received
Write Operations
Select a writable characteristic
Enter test data (e.g., “Hello BT”)
Perform a write operation
Check console for received data confirmation
Expected Logs:
System Initialization:
0000000124:[0][DBG][GENR]:created task for loop 0x300111e0
0000002715:[0][DBG][GENR]:created event loop 0x300111e0
0000005173:[0][INF][USB ]:Creating CDC0
0000006948:[0][INF][USB ]:USB CDC 0 created
0000008892:[0][INF][USB ]:USB CDC 1 created
0000010845:[0][INF][USB ]:USB CDC Performance Mode: Normal
0000013503:[0][INF][USB ]:USB device started
0000015524:[0][INF][XSPI]:Start XSPI (phy init, read id) with xspi_core_clk_freq 33MHz
0000019491:[0][INF][XSPI]:xspic check_flash_id: 0x1860c8
0000022036:[0][INF][XSPI]:flash : GigaDevice
0000024062:[0][INF][XSPI]:MAGIC number found, initialized with attributes from flash
0000027848:[0][INF][XSPI]:XSPI, configured_xspi_frequency 66MHz
0000030710:[0][INF][XSPI]:xspi_flash_initialized = true
0000033261:[0][WRN][LOGR]:Changing logger interface to LOGGER_IF_UART_1_CONSOLE
0000036762:[0][INF][SYS ]:
0000037958:[0][INF][SYS ]:SR110 SDK version 1.1.0
0000040164:[0][INF][SYS ]:System clock rate = 400 MHz
0000042535:[0][INF][SYS ]:soc_base_clock (slow_clk) rate = 24 MHz
0000045429:[0][INF][SYS ]:SysTick is clocked by slow_timer (XTAL) at rate of 24 MHz
0000049105:[0][INF][SYS ]:------------------------------------------
0000052128:[0][INF][SYS ]: Synaptics Bluetooth RTOS
0000055108:[0][INF][SYS ]:------------------------------------------
0000058145:[0][DBG][GENR]:running task for loop 0x300111e0
0000060736:[0][INF][USB ]:USB Device Driver task
0000062896:[0][INF][USB ]:USB device unmounted
0000064966:[0][INF][USB ]:USB stopped
0000066682:[0][DBG][HAPI]:UART0 initialized. Baudrate achieved: 230414
0000066711:[0][INF][HAPI]:------------------------------------------
0000066736:[0][INF][HAPI]: Host API Router task
0000066761:[0][INF][HAPI]:------------------------------------------
0000066785:[0][INF][HAPI]:Active interface is USB
0000081166:[0][INF][HAPI]:A new service was registered, service ID: 11.
0000081192:[0][DBG][GENR]:FW UPDATE TASK (srv_id = 11)
0000086744:[0][INF][SYS ]:------------------------------------------
0000089771:[0][INF][SYS ]: Hello ASTRA
0000092799:[0][INF][SYS ]:------------------------------------------
0000095826:[0][INF][SYS ]:System initialization done
0000246205:[0][INF][USB ]:USB device mounted
0000246231:[0][INF][USB ]:USB started
0000270712:[0][DBG][GENR]:no handlers have been registered for event USB_CDC_0_EVENTS:3 posted to loop 0x300111e0
000000001.008:vTaskShell, 1028
Command: synabt enable
000000009.908:recv cmd 13:synabt enable
000000009.908:[CLI][DEBUG] syna_bt_cli_tbl[0].handler called with argc=0, argv[2]=(null)
000000009.910:btapp_init free heap size:129192:free memory 0
000000009.913:Start Boot BT Stack
000000009.915:BTE_LoadGki
000000009.916:Starting UPIO initialization...
000000009.918:GPIO module initialized for port 0
000000009.920:Waiting for system boot completion before SWIRE_DATA reconfiguration...
000000011.924:GPIO 25 successfully configured for BT_REGON
000000011.924:GPIO 25 successfully configured for BT_REGON
000000012.026:UPIO initialization completed successfully
000000012.031:UPIO_Set type=4, pio=4, state=OFF
000000012.031:BT_REGON (GPIO25) set to 0
000000012.082:UPIO_Set type=4, pio=4, state=ON
000000012.082:BT_REGON (GPIO25) set to 1
000000012.133:UPIO_Restore_CTS_Setting: Not implemented
000000012.133:GKI_create_task:GKI Check task_id 1
000000012.134:GKI_create_task func=0x33ea4e05 id=1 name=gki_timer_task stack=0x3000ded0 stackSize=1024
000000012.139:GKI_create_task[1:1]!!!!
000000012.151:BootEntry:BTE_CreateTasks
000000012.151:[BTE_CreateTasks]:BTU_CreateTasks
000000012.152:GKI_create_task:GKI Check task_id 3
000000012.154:GKI_create_task func=0x33ec7661 id=3 name=btu_task stack=0x0 stackSize=16384
000000012.158:GKI_create_task[3:3]!!!!
000000012.160:[BTE_CreateTasks]:HCISU_CreateTasks
000000012.162:GKI_create_task:GKI Check task_id 5
000000012.164:GKI_create_task func=0x33ea34e5 id=5 name=hci_su_task stack=0x0 stackSize=2048
000000012.169:GKI_create_task[5:5]!!!!
000000012.171:[BTE_CreateTasks]:BTTAPP_CreateTasks
000000012.173:GKI_create_task:GKI Check task_id 2
000000012.175:GKI_create_task func=0x33ea19c5 id=2 name=btapp_task stack=0x0 stackSize=1024
000000012.179:GKI_create_task[2:2]!!!!
000000012.191:Initializing BT UART transport at 115200 baud
000000012.191:UART initialized: requested=115200, achieved=115207
000000012.193:BT UART transport initialized successfully
000000012.196:GKI_create_task:GKI Check task_id 6
000000012.198:GKI_create_task func=0x33ea5c8d id=6 name=hci_uart_task stack=0x0 stackSize=2048
000000012.205:GKI_create_task[6:6]!!!!
000000012.224:bte_post_reset, bte_patchram_has_dl:0
000000012.228:Reconfiguring UART baud rate to 3000000
000000012.228:Baud rate reconfigured: requested=3000000, achieved=3030303
000000012.231:bte_baud_update_cback status=0
000000017.757:Reconfiguring UART baud rate to 115200
000000017.757:Baud rate reconfigured: requested=115200, achieved=115207
000000017.764:Reconfiguring UART baud rate to 3000000
000000017.764:Baud rate reconfigured: requested=3000000, achieved=3030303
000000017.773:bte_post_reset, bte_patchram_has_dl:1
000000017.773:btapp_dm_post_reset
000000017.777:0017.777 [APPL ] btapp_cfg_init: tBTAPP_CFG size:104
000000017.780:0017.780 [APPL ] btapp_cfg_set_accept_auth_enable accept_auth_enable:0
000000017.783:0017.783 [APPL ] Local Addr:43:01:30:cc:ee:ff
000000017.786:BT stack lib version: 1.0.1_AMAZON_FREERTOS_SR110-(ASTRA_MCU_SDK1.0:ead4343)
000000017.789:BT stack lib built at 15:19:44 Sep 17 2025
000000017.792:SYN4612A1_001.002.003.0020.0000_Generic_UART_37_4MHz_wlbga_REF_sLNA_iLNA_ANT0_secure_sign_btpatch, size:137165
000000017.798:BT controller name:4612A1_Generic_UART_37_4MHz_wlbga_REF_sLNA_iLNA_ANT0 [Baseline: 0020]
000000017.887:0017.887 [APPL ] bta_dm_ctrl_features_rd_cmpl_cback status = 0
000000017.896:0017.896 [APPL ] bta_sys_hw_btm_cback was called with parameter: 0
000000017.899:bte_dev_reset_cplt
000000017.899:0017.899 [APPL ] bta_sys_sm_execute state:0, event:0x2
000000018.086:btapp_init stack bring-up success!
000000018.086:[btapp_startup]:btapp_init_device_db
000000018.087:BTA_BrcmInit!
000000018.089:0018.089 [APPL ] BTA_BrcmInit
000000018.091:BTA_EnableBluetooth
000000018.095:0018.095 [APPL ] bta_sys_sm_execute state:2, event:0x0
000000018.098:0018.098 [APPL ] bta_dm_sys_hw_cback with event: 1
000000018.101:btapp_dm_security_cback event 0
000000018.101:btapp_dm_init_continue privacy_enabled = 0
000000018.104:0018.104 [APPL ] BTA_DmBleScatternetEnable: 1
000000018.107:0018.107 [APPL ] Adding UUID=0x1200 into EIR
000000018.110:0018.110 [APPL ] BTA is generating EIR
000000018.113:0018.113 [APPL ] bta_dm_eir_update_uuid UUID bit mask=0x00000004 00000000
000000018.119:local bdaddr 43:01:30:cc:ee:ff
000000018.119:auth_req:4
000000018.122:btapp_init success!
000000018.122:btapp_init free heap size:35136
000000018.126:0018.126 [APPL ] bta_sys_hw_api_enable for 0, active modules 0x0001
000000018.129:0018.129 [APPL ] BTA is generating EIR
000000018.132:0018.132 [APPL ] bta_brcm_evt_hdlr :0x0005
000000018.183:btapp_dm_security_cback event 20
000000018.189:btapp_dm_security_cback event 21
Command: synabt gatt_server_start
000000027.724:recv cmd 24:synabt gatt_server_start
000000027.724:[CLI][DEBUG] syna_bt_cli_tbl[14].handler called with argc=0, argv[2]=(null)
000000027.727:0027.727 [APPL ] BTA_DmSetBleAdvParam: 32, 64
000000027.732:0027.732 [APPL ] bta_gatts_enable: num of handle range added=0
000000027.735:0027.735 [APPL ] bta_gatts_co_srv_chg cmd=4
000000027.738:0027.738 [APPL ] register application first_unuse rcb_idx = 0
000000027.741:btapp_gatts_cback event:0
000000027.744:GATTS registered...sif:3, status:0
000000027.747:0027.747 [APPL ] create service rcb_idx = 0
000000027.747:btapp_gatts_cback event:7
000000027.750:btapp_gatts_cback BTA_GATTS_CREATE_EVT
000000027.753:0027.753 [APPL ] bta_gatts_find_srvc_cb_by_srvc_id service_id=40
000000027.756:0027.756 [APPL ] bta_gatts_find_srvc_cb_by_srvc_id found service cb index =0
000000027.762:btapp_gatts_cback event:9
000000027.762:btapp_gatts_cback BTA_GATTS_ADD_CHAR_EVT status:0, attr_id:42
000000027.765:0027.765 [APPL ] bta_gatts_find_srvc_cb_by_srvc_id service_id=40
000000027.771:0027.771 [APPL ] bta_gatts_find_srvc_cb_by_srvc_id found service cb index =0
000000027.774:btapp_gatts_cback event:10
000000027.777:btapp_gatts_cback BTA_GATTS_ADD_CHAR_DESCR_EVT status:0, attr_id:43
000000027.780:0027.780 [APPL ] bta_gatts_find_srvc_cb_by_srvc_id service_id=40
000000027.783:0027.783 [APPL ] bta_gatts_find_srvc_cb_by_srvc_id found service cb index =0
000000027.789:0027.789 [APPL ] bta_gatts_start_service service_id= 40
000000027.792:btapp_gatts_cback event:12
000000027.795:btapp_gatts_cback BTA_GATTS_START_EVT
Command: synabt ble_start_adv
000000025.830:recv cmd 20:synabt ble_start_adv
000000025.830:[CLI][DEBUG] syna_bt_cli_tbl[2].handler called with argc=0, argv[2]=(null)
000000025.833:0025.833 [APPL ] BTA_DmSetBleAdvParam: 32, 64
GATT Write Operation from Connected Device:
000000105.866:btapp_gatts_proc_write handle:42, len:8, offset:0, need_rsp:1, is_prep:0
000000105.872:Peer wrote content: |hello!!!|
000000105.872:0105.872 [APPL ] bta_gatts_send_rsp found p_rcb
000000105.875:btapp_gatts_cback event:24