[Introduction]：E48-433T20S is a domestic cost-effective wireless data transmission module launched by Chengdu Ebyte.It supports frequency hopping, automatic retransmission and other transmission methods, which can be applied to various IoT application scenarios. The wireless module works in the 410~450MHz frequency band, has TTL level output, supports a maximum transmit power of 20dBm, and is compatible with 3.3V IO port voltage. It supports functions such as air wake-up, wireless configuration, relay networking, communication keys, etc. At the same time, the module has a data encryption function. Through strict encryption and decryption algorithms, it ensures data security and improves communication reliability and transmission efficiency.
| Pin number | Pin name | Pin direction | Pin usage |
| 1 | GND | - | Module ground wire |
| 2 | GND | - | Module ground wire |
| 3 | GND | - | Module ground wire |
| 4 | GND | - | Module ground wire |
| 5 | M0 | Input (very weak pull-up) | Cooperate with M1 to determine the 4 working modes of the module. (Can be left floating, the module contains a pull-up resistor) |
| 6 | M1 | Input (very weak pull-up) | Cooperate with M0 to determine the 4 working modes of the module. (Can be left floating, the module contains a pull-up resistor) |
| 7 | RXD | Input | TTL serial port input, connected to the external TXD output pin; |
| 8 | TXD | output | TTL serial port output, connected to the external RXD input pin; |
| 9 | AUX | output | Used to indicate the working status of the module. The user wakes up the external MCU and outputs low level during power-on self-test initialization. |
| 10 | VCC | - | Module power supply positive reference, voltage range: 2.7V ~ 5.5V DC |
| 11 | GND | - | Module ground wire |
| 12 | RST | - | Reset pin, active low |
| 13 | GND | - | Module ground wire |
| 14 | NC | - | - |
| 15 | NC | - | - |
| 16 | NC | - | - |
| 17 | NC | - | - |
| 18 | NC | - | - |
| 19 | GND | - | Module ground wire |
| 20 | GND | - | Module ground wire |
| 21 | ANT | - | antenna |
| 22 | GND | - | Module ground wire |