Bluetooth LE–FR801x

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\FR8018HA\chip_manual\.

Development board

You can purchase the FR8018HA Bluetooth development board (part number: 2.05.03.00198) from the Tuya IoT Development Platform.

Peripherals

PMU

The FR801xH series has four sets of I/O pins, with eight pins per set. The number of I/O pins brought out varies by chip model. Each I/O pin can be set to pull-up mode. The pull-up resistor is about 50 kΩ. The operating state and mode of an I/O pin can be controlled by either the CPU or power management unit (PMU).

• PMU: operates in low power mode.
• CPU: powers off in low power mode.

Unlike PMU, peripherals controlled by the CPU are re-initialized when waking up from sleep.

The following diagram shows the control logic and function configuration.

GPIO

The FR8018H has 32 GPIOs, but not all of them are brought out. PC4 is completely unavailable.

When testing GPIO input and output, the logic pin numbers used in the host software range from 0 to 31. Here are their corresponding physical pin names:

FR8018H	Logic	FR8018H	Logic	FR8018H	Logic	FR8018H	Logic
PA0	0	PB0	8	PC0	16	PD0	24
PA1	1	PB1	9	PC1	17	PD1	25
PA2	2	PB2	10	PC2	18	PD2	26
PA3	3	PB3	11	PC3	19	PD3	27
PA4	4	PB4	12	PC4	20	PD4	28
PA5	5	PB5	13	PC5	21	PD5	29
PA6	6	PB6	14	PC6	22	PD6	30
PA7	7	PB7	15	PC7	23	PD7	31

UART

This platform has two UARTs (UART0 and UART1). You can map the UART to any of the I/O pins. The serial port testing feature in the host software can only test two specified I/Os.

UART	Feature	Pin	Description
UART0	TX	PA1	Log
UART0	RX	PA0
UART1	TX	PA3	Flashing, authorization, and testing.
UART1	RX	PA2

SPI (SSP)

In the FR8018 datasheet and .c files, SPI is described as SSP. FR8018H has only one SSP peripheral, which is the SSP0. You can connect SSPDIN and SSPDOUT to perform a test.

SSP	Pin	Pin
SSP0	CS	PA5
SSP0	SSPCLK	PA4
SSP0	SSPDIN	PA7
SSP0	SSPDOUT	PA6

Rate:

• 125000
• 250000
• 500000
• 1000000
• 2000000

I2C

FR8018H has two I2Cs, which can be mapped to any of the I/O pins (except for PC4). To display SDK information (TuyaOS demo), the OLED is pre-initialized. Therefore, only one I2C can be used for testing.

Feature	Pin
I2C0_SCL	PD0
I2C0_SDA	PD1

PWM

Channel	Pin
0	PC0
1	PC1
2	PC2
3	PC3
4	PB4
5	PB5

ADC

Only support 10-bit resolution.

Channel	Pin
0	PD4
1	PD5
2	PD6
3	PD7

Key control

PB6 (14)
Press the button to wake up the device.
Press and hold the button for three seconds to factory reset the device.

Power-on detection pin

PC5 (21)
Set this pin to high after entering the main function.

Software 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.

   

Develop software

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. After a full compilation of the whole project, open the .map file. The flash and RAM footprint:

   

OTA

Before an OTA firmware update, modify the version number firmware_version in proj_main.c. The bootloader checks the version number at each update. The new version must be higher than the previous one.

os_timer

os_timer cannot be used in an interrupt. This is because ke_timer_set in os_timer manipulates the linked list. The underlying Bluetooth stack uses ke_timer_set. When the underlying stack uses ke_timer_set, if os_timer is called by an interrupt, ke_timer_set will manipulate the same linked list in the interrupt. This can disrupt the linked list and result in problems.

Firmware flashing

Wire connection

To flash firmware to the device, connect the device and the USB to TTL converter as described below.

USB to TTL converter	Device
VCC	VCC
GND	GND
TX	RX (PA2)
RX	TX (PA3)

Firmware description

The production firmware and the OTA update use the same file, as shown below.

Flashing method

1. Open the flashing tool from pc\tools\FR8018HA\tools\FR8010H_Download_Tool.exe.

2. Connect the device to the computer through a USB to TTL converter.

3. Import the firmware binary file and proceed with erasing and writing.

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

Flash partitions and sizes

• 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        (0x74000)
  #endif
  
  #ifndef BOARD_FLASH_TUYA_INFO_START_ADDR
  #define BOARD_FLASH_TUYA_INFO_START_ADDR        (0x78000)
  #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              (0x32000)
  #endif
  
  #ifndef BOARD_FLASH_OTA_END_ADDR
  #define BOARD_FLASH_OTA_END_ADDR                (0x64000)
  #endif
  
  #ifndef BOARD_FLASH_OTA_SIZE
  #define BOARD_FLASH_OTA_SIZE                    (BOARD_FLASH_OTA_END_ADDR - BOARD_FLASH_OTA_START_ADDR)
  #endif
  

• To change the OTA memory location, besides editing the above macro, you also need to change the start address in proj_main.c accordingly.

  

Power consumption

Measure the average power consumption of typical one-second advertising for over 100 seconds.

Local clock testing

The local clock has a time drift of less than one second within 12 hours.