[RF chip]：STM32WL33
[Transmitting power]： 20dBm
[Communication distance]： 3500m
[Product size]：20*14mm
[Introduction]：E04-400M20S is a SoC wireless communication module based on STMicroelectronics' newly launched STM32WL33 chip solution. The wireless module has the characteristics of long communication distance, low standby power consumption, strong anti-interference ability, rich interface resources, strong processing ability, and small size. It is also suitable for 433/470 frequency band patch wireless modules, using industrial-grade high-precision 32.768KHz and 48MHz crystal oscillators to ensure stable operation of the module. This wireless module requires secondary development by the user and can be widely used in the Internet of Things industry.
| RF parameters | Parameter value | Remark |
| Working frequency band | 413~478 MHz | Support ISM frequency band |
| Transmit power | 0~20 dBm | The software is adjustable and requires users to develop settings by themselves. |
| Receive sensitivity | -132 dBm | @1% OFF |
| Communication distance | 3500 meters | Sunny and open environment, maximum power, antenna gain 3.5dBi, height 2m, airspeed 1.2kbps |
| Hardware parameters | Parameter value | Remark |
| IC full name | STM32WL33KCV6 | - |
| Kernel | ARM Cortex-M0+ | - |
| FLASH | 256 KB | - |
| RAM | 32 KB | - |
| Crystal frequency | 48MHz/32.768KHz | External crystal oscillator |
| Size | 14 * 20 mm | - |
| Antenna form | IPEX/stamp hole | Equivalent impedance is about 50Ω |
| Communication interface | UART、SPI、I²C、GPIO、ADC | Users need to develop their own settings |
| Packaging method | patch stamp hole | - |
| weight | 1.2g | ±0.1g |
| Electrical parameters | minimum value | Typical value | maximum value | unit | Remark |
| Supply voltage | 2.8 | 3.3 | 3.6 | V | ≥3.3V guarantees output power, exceeding 3.6V may damage the module |
| Communication level | - | 3.3 | - | V | When using 5.0V TTL, it is recommended to add level conversion |
| Emission current | - | 150 | - | mA | Instantaneous power consumption |
| receive current | - | 18 | - | mA | - |
| Sleep current | - | 2.5 | - | μA | - |
| working temperature | -40 | 20 | 85 | ℃ | - |
| Working humidity | 10 | 60 | 90 | % | - |
| storage temperature | -40 | 20 | 125 | ℃ |
