[Bluetooth protocol]：BLE 5.0
[Communication distance]：150m
[Product size]：13*19mm
[Introduction]：E104-BT09 Bluetooth module is a Bluetooth-to-serial slave module based on the BLE 5.0 protocol developed by Ebyte based on the Telink Micro TLSR8208BER chip. It is small in size, has low power consumption and works in the 2.4GHz frequency band. The Bluetooth module uses ordinary AT commands to set parameters, and the operation is simple and fast. The Bluetooth to serial port module supports slave role, Bluetooth broadcast, data transparent transmission and wireless configuration. Modified Bluetooth modules can be widely used in smart wear, home automation, home security, personal healthcare, smart home appliances, accessories and remote controls, etc.
| Pin number | Pin definition | Chip pin | Pin direction | Remarks |
| 1 | GND | GND | - | Modular ground |
| 2 | TXD | PD0 | output | Serial port sending pin |
| 3 | RXD | PD1 | enter | Serial port receiving pin |
| 4 | NC | PD2 | - | - |
| 5 | NC | PD4 | - | - |
| 6 | NC | PD6 | - | - |
| 7 | NC | PD7 | - | - |
| 8 | SWS | PA3 | Program download | |
| 9 | NC | PA7 | - | - |
| 10 | NC | PB3 | - | - |
| 11 | RESTORE | PB2 | enter | After internal pull-up, falling edge, and then keeping low level for at least 5 seconds, all parameters will be restored to factory settings and the module will be automatically restarted. |
| 12 | GND | DVSS | - | Modular ground |
| 13 | WKP | PB4 | enter | The default is low level, low power consumption mode, and the serial port cannot communicate. Pull it high to enter normal working mode, and the serial port can communicate. |
| 14 | VBAT | VBAT | enter | Battery power supply, supports 1.8 V ~ 4.2 V power supply |
| 15 | AVDD3 | AVDD3 | enter | Positive power supply, 1.8V~3.6V, 3.3V power supply recommended |
| 16 | GND | GND | - | Modular ground |
| 17 | BAT_DET | PB5 | enter | Battery voltage detection, see section 6.2.16 for details |
| 18 | LINK | PB6 | output | Connection status indication pin, high level indicates connected, low level indicates disconnected |
| 19 | NC | PB7 | - | - |
| 20 | GND | GND | - | Modular ground |
| 21 | GND | GND | - | Modular ground |
| 22 | NC | PC0 | - | - |
| 23 | NC | PC1 | - | - |
| 24 | GND | GND | - | Modular ground |
| 25 | GND | GND | - | Modular ground |
| 26 | RESET | RESETB | enter | Reset pin, active low, internal pull-up |