[Chip solution]：SI4438
[Carrier frequency]：425~525MHz
[Transmit power]：30dBm
[Communication distance]：5.6km
[Product size]：38.5*24mm
[Introduction]：E30-400M30S(4438) is a hardware module (SPI) based on the SI4438 RF chip imported from Silicon Labs. It is half-duplex, integrates transceiver and receiver, transparent transmission mode, SMD type, working frequency band is 425~525MHz, transmit power 1W , suitable for a variety of environments, using the SI4438 RF chip originally imported from the American Silicon Labs company, with high receiving sensitivity, strong anti-interference, and supports the development of low power consumption. It has been widely used in various industries, and has the characteristics of stable performance, long transmission distance, penetration and diffraction ability, etc.
| No. Pin | Pin | Direction | Remarks |
| 1 | GND | Module ground | |
| 2 | GND | Module ground wire | |
| 3 | GND | Module ground wire | |
| 4 | GND | Module ground wire | |
| 5 | GND | Module ground wire | |
| 6 | IO2 | output | Configurable general-purpose GPIO port (see SI4463 manual for details) |
| 7 | IO3 | output | Configurable general-purpose GPIO port (see SI4463 manual for details) |
| 8 | IO0 | output | Configurable general-purpose GPIO port (see SI4463 manual for details) |
| 9 | VCC | Power supply, range 3.3~5.5V, 5V is recommended, it is recommended to add ceramic filter capacitors externally | |
| 10 | VCC | Power supply, range 3.3~5.5V, 5V is recommended, it is recommended to add ceramic filter capacitors externally | |
| 11 | GND | Module ground wire | |
| 12 | GND | Module ground wire | |
| 13 | IO1 | output | Configurable general-purpose GPIO port (see SI4463 manual for details) |
| 14 | IRQ | output | Module interrupt output pin |
| 15 | SDN | Module work enable control pin, low level when working (see SI4463 manual for details) | |
| 16 | MISO | output | Module SPI data output pin |
| 17 | MOSI | intput | Module SPI data input pin |
| 18 | SCK | intput | Module SPI clock pin |
| 19 | NSEL | intput | Module chip select pin, used to start a SPI communication |
| 20 | GND | Module ground wire | |
| 21 | ANT | Antenna | |
| 22 | GND | Module ground wire |