Project Zero
Table of Contents
Introduction
The project_zero project implements a simple Bluetooth low energy peripheral
device with GATT services and demonstrates how to integrate Over the Air
Download and three custom services. This project can be a framework for
developing many different peripheral-role applications.
This project has the following app configurations available:
| App Build Configuration | Description |
|---|---|
| FlashROM_Release (default) | All TI-RTOS debug features disabled but application-logging to UART remains enabled. The application uses the config file ble_release.cfg and the defines are in <app name>_FlashROM_Release.opt. |
| FlashROM_Debug | All TI-RTOS debug features enabled. The application uses the config file ble_debug.cfg and the defines are in <app name>_FlashROM_Debug.opt. |
All application configurations use the stack library configuration, FlashROM_Library. This build configuration will yield additional flash footprint optimizations by the linker since the application and stack can share contiguous flash pages. This configuration is further discussed in the Stack Library Configuration section of the BLE5-Stack User's Guide provided in the SDK.
Note on the Boot Image Manager
This project is configured to be managed and launched by the BIM or Boot Image Manager example app. This means that this project does not include a CCFG section to configure the device at boot, and therefore requires that the BIM project is programmed into the device first.
The application supports secure OAD i.e. Image authentication needs to be done before executing the newly tranferred image. This is done by the BIM example app. A security header is added to this application image in order to support this.
If BIM is not present in the device internal Flash, the project can usually be started from the IDE but will not be executed after a pin reset. Read more about BIM and OAD in the BLE5-Stack User's Guide.
Hardware Prerequisites
The default Project Zero board configuration uses the device's LaunchPad development kit. This hardware configuration is shown in the below image:
For custom hardware, see the Running the SDK on Custom Boards section of the BLE5-Stack User's Guide.
Software Prerequisites
For information on what versions of Code Composer Studio and IAR Embedded Workbench to use, see the Release Notes file provided in the SDK. For information on how to import this project into your IDE workspace and build/run, please refer to the device's Platform section in the BLE5-Stack User's Guide.
Service/Profile Table
This project contains 3 services in addition to GAP, GATT, Device Information and OAD.
LED Service
This service exposes two readable and writeable characteristics, LED0 and
LED1 which both expect 1 byte of data. Writing 0 to either of the
characteristic value attributes will turn off the corresponding LED on the
Launchpad. Writing anything other than 0 will turn the LED on.
| Description | UUID | Format | Properties |
|---|---|---|---|
| LED Service | F0001110-0451-4000-B000-000000000000 | Service declaration | Read |
| LED0 State | F0001111-0451-4000-B000-000000000000 | 1 byte uint8_t | Read/Write |
| LED1 State | F0001112-0451-4000-B000-000000000000 | 1 byte uint8_t | Read/Write |
Button Service
This service exposes to readable and notifiable characteristics, BUTTON0 and
BUTTON1 which correspond to the hardware switches BTN-1 and BTN-2
respectively. The state of each is updated when the hardware switch is
pressed, and this can be read out via BLE. If notifications are enabled on
these characteristics the button states will be sent out as notifications.
| Description | UUID | Format | Properties |
|---|---|---|---|
| Button Service | F0001120-0451-4000-B000-000000000000 | Service declaration | Read |
| BUTTON0 State | F0001121-0451-4000-B000-000000000000 | 1 byte uint8_t | Read/Notify |
| BUTTON1 State | F0001122-0451-4000-B000-000000000000 | 1 byte uint8_t | Read/Notify |
Data Service
This service exposes a long (longer than legacy MTU size) characteristic
String char and a characteristic that is meant to exemplify streaming,
Stream char. In order to read the entire contents of String char, a client
must either have negiotated a longer MTU size than the default 27 bytes, or
must use the GATT Long Read procedure.
| Description | UUID | Format | Properties |
|---|---|---|---|
| Data Service | F0001130-0451-4000-B000-000000000000 | Service declaration | Read |
| String char | F0001131-0451-4000-B000-000000000000 | Up to 40 byte uint8_t | Read/Write/WriteNoRsp |
| Stream char | F0001132-0451-4000-B000-000000000000 | Up to 20 byte uint8_t | WriteNoRsp/Notify |
Usage
This application uses the UART peripheral to provide an interface for the application. The UART is only used for display messages.
We recommend that you use a terminal program that can parse ANSI/VT100 color codes such Tera Term, PuTTY, Code Composer Studio Terminal, etc. to to monitor the LaunchPad UART output.
To interact with the application over Bluetooth you may use any device that is able to act as a BLE Central device, such as
iOS with the apps SimpleLink Starter or LightBlue
Android with the apps SimpleLink Starter or BLEScanner
A CC26xx/CC13xx LaunchPad running the sample app HostTest from a compatible SDK with the PC tool BTool from the same SDK.
Please see the Readme for simple_peripheral for an example of how
to connect with a smartphone.
The following default parameters are used for the UART peripheral for display:
| UART Param | Default Values |
|---|---|
| Baud Rate | 115200 |
| Data length | 8 bits |
| Parity | None |
| Stop bits | 1 bit |
| Flow Control | None |
Booting
Once the Project Zero sample application starts, the output to the terminal will report its address and the fact that it is advertising, as shown below:
During boot/application init some activities related to Boot Image Mananger
(BIM) and the external flash also take place:
The call to
OAD_openwill check if a factory image exists in external flash. If none exists, the running image will be copied to external flash and marked as factory image.BTN-1, the left button, is checked. If it is held down from reset, a 5 second timeout elapses before the running image marks itself as invalid and reboots into BIM. The purpose of this is to make BIM revert to the factory image to internal Flash.The combination
BTN-1andBTN-2is checked. If both buttons are held down for 5 seconds, the external Flash will be erased.
After application init both buttons will operate normally. If the buttons are released during the 5 second timeout, the device will continue booting normally.
NOTE: After erasing the external flash it is not recommended to perform the
BTN-1 + Reset revert procedure as this leave the Boot Image Manager
with no valid image in internal Flash and no factory image in external
Flash. At this point a debugger like the on-board XDS110 must be used
to download a new internal image to the device.
Pressing only Reset after erasing external Flash will invoke the
OAD_open self-backup functionality on boot and revert will function
normally again.
Connecting
When a device connects, the address of the device will be shown in the console. After a while you will see the automatic parameter update request sent from the device being applied.
