CB3L Wi-Fi Module

by Tuya Inc.

Parameter	Value
Board code	`cb3l`
MCU	BK7231N
Manufacturer	Beken
Series	BK72XX
Frequency	120 MHz
Flash size	2 MiB
RAM size	256 KiB
Voltage	3.0V - 3.6V
I/O	12x GPIO, 6x PWM, 2x UART, 1x ADC
Wi-Fi	802.11 b/g/n
Bluetooth	BLE v5.1
FCC ID	2ANDL-CB3L

Usage

Board code: cb3l

In platformio.ini:

[env:cb3l]
platform = libretuya
board = cb3l
framework = arduino

In ESPHome YAML:

libretuya:
  board: cb3l
  framework:
    version: dev

Pinout

Arduino Core pin mapping

No.	Pin	UART	I²C	SPI	PWM	Other
D0	P23					TDO
D1	P14			SCK
D2	P26				PWM5
D3	P24				PWM4
D4	P6				PWM0
D5	P9				PWM3
D6	P0	UART2_TX	I2C2_SCL
D7	P21		I2C1_SDA			TMS
D8	P8				PWM2
D9	P7				PWM1
D10	P10	UART1_RX
D11	P11	UART1_TX
A0	P23, ADC3

Flash memory map

Flash size: 2 MiB / 2,097,152 B / 0x200000

Hex values are in bytes.

Name	Start	Length	End
Bootloader	0x000000	68 KiB / 0x11000	0x011000
App Image	0x011000	1.1 MiB / 0x119000	0x12A000
OTA Image	0x12A000	664 KiB / 0xA6000	0x1D0000
Calibration	0x1D0000	4 KiB / 0x1000	0x1D1000
Network Data	0x1D1000	4 KiB / 0x1000	0x1D2000
TLV Store	0x1D2000	4 KiB / 0x1000	0x1D3000
Key-Value Store	0x1D3000	32 KiB / 0x8000	0x1DB000
User Data	0x1DB000	148 KiB / 0x25000	0x200000

Bootloader and app partitions contain CRC16 sums every 32 bytes. That results in the actual flash offsets/sizes not aligned to sector boundaries. To simplify calculations, the values shown in the table (extracted from bootloader's partition table) were aligned to 4096 bytes.