Bluetooth LE–nRF52832

This topic describes the basics of the chip platform used in TuyaOS development. For more information, visit Tuya Developer Forum.

Hardware environment

Datasheet

• The datasheet can be found in hardware\nRF52832\chip_manual\nRF52832_PS_v1.7.pdf.

• Alternatively, check the Nordic Semiconductor website for the latest information.

Development board

• You can purchase the nRF52832 Bluetooth development board (part number: 2.03.99.00045) from the Tuya IoT Development Platform. This board uses Tuya’s Bluetooth LE dongle hardware.

  Schematic diagram of the dongle: hardware\nRF52832\module_manual.

  

• Alternatively, use Nordic development board and check the official documentation.

  

Peripherals

UART

This platform has one UART, used for authorization and debugging.

UART	Feature	Pin
UART 0	TX	P0.06
UART 0	RX	P0.08

SPI

When multiple peripherals use the same register address, only one of them can be used at a time. The SPI supports SPI1 and SPI2.

SPI	Feature	Pin
SPI1	CS	P0.05
SPI1	CLK	P0.04
SPI1	SDI	P0.02
SPI1	SDO	P0.03
SPI2	CS	P0.28
SPI2	CLK	P0.29
SPI2	SDI	P0.30
SPI2	SDO	P0.31

I2C

When multiple peripherals use the same register address, only one of them can be used at a time. The I2C supports I2C0.

I2C	Feature	Pin
I2C0	SCL	P0.16
I2C0	SDA	P0.15

PWM

Channel	Pin
0	P0.28
1	P0.29
2	P0.30
3	P0.31

ADC

Channel	Pin
0	P0.02
1	P0.03
2	P0.04
3	P0.05
4	P0.28
5	P0.29
6	P0.30
7	P0.31

Key control

P0.14

• Press the button to wake up the device.
• Press and hold the button for three seconds to factory reset the device.

Startup time detection pin

P0.05

Set this pin to high after entering the main function.

Software environment

Install Keil and nRF52832-dependent environment.

Keil

1. Download Keil from the Arm Keil website. mdk528a.exe is recommended. During installation, keep all the default settings.

2. If you are prompted to install a driver, continue with Install.

3. When opening Keil, if you are prompted to install a software pack, close the window.

4. After Keil is installed, add the path of the UV4.exe file to the environment variable. For example: TUYAOS_COMPILE_TOOL: C:\Keil_v5\UV4, as shown below.

   

nRF Command Line Tools

nRF Command Line Tools contain J-Link software and Nordic Semiconductor’s command-line tools, such as J-Link drivers, nrfjprog executable, nrfutil, and mergehex executable.

The steps to install nRF Command Line Tools are as follows, taking Windows as an example.

1. Download nRF Command Line Tools from Nordic Semiconductor.

2. Choose platform and version. For example, the installer for Win32 can be nRF5x-Command-Line-Tools_9_8_1_Installer.exe.

   

3. Double-click the .exe file and accept the license agreement to install. During installation, keep all the default options.

   

4. When you get the following screen, make sure to check select all.

   

Arm’s CMSIS

1. Click to download Arm’s CMSIS.
2. Follow the prompts to complete the installation.

Device Family Pack

1. Click to download Device Family Pack.

2. Follow the prompts to complete the installation.

   Do not let Keil automatically download Device Family Pack. Otherwise, the compilation might fail.

J-Link

1. Download J-Link from Segger.

2. Choose the appropriate version (V6.88c is used for testing) and follow the prompts to complete the installation.

   

Develop software

Enable scanning

#define     TKL_BLUETOOTH_SUPPORT_SCAN      (1)

Flash and RAM footprint

1. Disable the testing feature.

   #define TUYA_SDK_TEST 0
   

2. Disable Tuya logging.

   #define ENABLE_LOG 0
   #define BOARD_ENABLE_LOG 0
   

3. Disable chip vendor logging.

   

4. Disable scanning.

   #define     TKL_BLUETOOTH_SUPPORT_SCAN      (0)
   

5. After a full compilation of the whole project, open the .map file. You will get the RAM and flash footprint.

   

   About 10 KB data of RW is actually stored in flash, so the actual used RAM is about 26 KB, as shown below.

   

   When you enable scanning

   #define     TKL_BLUETOOTH_SUPPORT_SCAN      (1)
   

   After a full compilation of the whole project, open the .map file. You will get the RAM and flash footprint.

   

Firmware flashing

Wire connection

Select SW mode in J-Link and connect J-Link and the device as described below.

J-Link	Device
VCC	VCC
GND	GND
DIO	DIO
CLK	CLK

Firmware description

Flashing method 1

1. In Visual Studio Code, right-click apps\tuyaos_demo_ble_peripheral in the Explorer and choose Reveal in File Explorer.

   

2. Open tuyaos_demo_ble_peripheral\_build\hex.

3. Double-click load_softdevice_bootloader_app.bat to flash firmware.

   The full firmware will be flashed to the device. After the firmware is flashed, you need to perform authorization.

Flashing method 2

Flash firmware to the device by using Download in Keil. Only the application-level code can be flashed.

Flashing method 3

Use J-Flash to flash firmware. You may need to learn how to use J-Flash by yourself.

Flashing method 4

Use nRF Connect for Desktop to flash firmware.

Features

Startup time

• Use a logic analyzer to measure the signal time difference between the VCC pin and the startup time detection pin.

• Detection pins: peripheral → startup time detection pin

  

Flash partition

Adjust flash partitions

In the original project, you can modify the following macros to adjust the default flash partitions.

// Flash
#ifndef BOARD_FLASH_BULK_DATA_START_ADDR
#define BOARD_FLASH_BULK_DATA_START_ADDR        (0x70000)
#endif

#ifndef BOARD_FLASH_TUYA_INFO_START_ADDR
#define BOARD_FLASH_TUYA_INFO_START_ADDR        (0x74000)
#endif

// #ifndef BOARD_FLASH_OTA_INFO_ADDR
// #define BOARD_FLASH_OTA_INFO_ADDR               (0x7C000)
// #endif

#ifndef BOARD_FLASH_OTA_START_ADDR
#define BOARD_FLASH_OTA_START_ADDR              (0x46000)
#endif

#ifndef BOARD_FLASH_OTA_END_ADDR
#define BOARD_FLASH_OTA_END_ADDR                (0x66000)
#endif

#ifndef BOARD_FLASH_OTA_SIZE
#define BOARD_FLASH_OTA_SIZE                    (BOARD_FLASH_OTA_END_ADDR - BOARD_FLASH_OTA_START_ADDR)
#endif

// #ifndef BOARD_FLASH_MAC_START_ADDR
// #define BOARD_FLASH_MAC_START_ADDR              (0)
// #endif

Power consumption

• If the TuyaOS Bluetooth LE SDK enables the DCDC mode, the device can enter a lower power mode.

• Not enabling DCDC mode can result in higher power consumption.

  Measure the average power consumption of typical one-second advertising.