User Manual
HLK-B40
1. Introduction
HLK-B40 is a kind of Master-Slave serial port transmission Bluetooth module based on BLE5.1, All kinds of
devices with serial port can use Bluetooth wireless to send and receive data simply and quickly through this module.
The basic functions and features are as follows
，
Main frequency 48MHz, 32-bit ARM Cortex M3 core
Fast and stable Bluetooth-serial port transmission, serial port rate up to 921600
Master-to-one Bluetooth, which can be set to host or slave mode, supports binding encryption
Bluetooth from the machine mode can be connected by up to 20 host devices at the same time, supporting custom
broadcast data
Based on BLE5.1, it is faster and has a longer transmission distance and can reach 40 to 100 m in an open
environment
Supports low-power modes, sleep currents of up to6 μA and custom connection and broadcast intervals
Bluetooth transmit power can be adjusted up to 10dBm and receives up to -95dBm
Support for OTA Bluetooth wireless upgrade module firmware, wireless configuration module parameters
The default on-board high-quality ceramic antenna increases the transmission distance and includes an
external antenna
Built-in Watchdog, Long and reliable operation time
Ultrasmall size
14mm×9.5mm×2mm
Wide operating voltage 1.8 to 4.2V, typical 3.3V
Rich output pins (UART, I2C, SPI, up to 15 GPIOs, up to 4 ADCs, up to 6 PWMs) provide flexible and
in-depth hardware and software custom development services
2. Pin definition
Figure 1 Pin Position Diagram
