BT3L Module

This topic describes the low power embedded Bluetooth module BT3L developed by Tuya Smart.

Overview

BT3L is a low power embedded Bluetooth module developed by Tuya Smart. The module consists of a highly integrated Bluetooth chip TLSR8250F512ET32 and a few peripheral components, with a built-in Bluetooth network protocol stack and various library functions. BT3L also contains a low power 32-bit MCU, BLE5.0/2.4G radio, 4 Mbit flash, 48 KB static random access memory (SRAM), and 9 reusable I/O ports.

For more information, see BT3L Module Datasheet.

Typical application diagram

• Figure 1 is a reference diagram of the coordinated processing mode of the module and 3.3 V MCU.
  

  

• Figure 2 is a reference diagram of the coordinated processing mode of the module and 5 V MCU.
  

Design specification

• Module power supply:

  • It is recommended that the supply current of the 3.3V module should exceed 100 mA, and the total capacity of the external filter capacitor should exceed 10 uF.
  • In the PCB layout, the filter capacitor at the power input pin shall be arranged near the power supply pin.

• Module pin:

  • A power on reset (POR) circuit is added inside the RST pin. Also, the module can be controlled by general-purpose input/output (GPIO) ports of the MCU. Pay attention to electrical level conversion.
  • The TL_B5 pin is the low power control pin of the module. The signal is sent by the MCU and received by the module.
  • The TL_B4 pin is the connection status indicator pin. The signal is sent by the module and received by the MCU.

• Radio frequency (RF) of the module: It is recommended that the distance between the module antenna and other metal parts should be at least 15 mm, in order to optimize the RF performance. If metal materials are wrapped around the antenna in the environment, the wireless signal will be greatly attenuated and the radio frequency performance will deteriorate.

  Note: When designing the finished product, reserve enough space for the antenna area.