HLK-RM04 is a new low-cost embedded UART-ETH-WIFI module (serial port - Ethernet - Wireless network) developed by Shenzhen Hi-Link Electronic co., Ltd.This product is an embedded module based on the universal serial interface network standard, built-in TCP / IP protocol stack, enabling the user serial port, Ethernet, wireless network (wifi) interface between the conversions.Through the HLK-RM04 module, the traditional serial devices do not need to change any configuration; data can be transmitted through the Internet network. Provide a quick solution for the user’s serial devices to transfer data via Ethernet.

Down Datasheet here

 

 

 

         Picture1.F-structure

 

 

 

HLK-RM04 Mechanical Dimensions is shown in the following picture：

3.Pin Interface
The Pin of this product as shown above is defined as follows

4.Electrical Characteristics 
Exceeding these conditions will result in damage to the device 

Parameter	Min	Max
Module supply voltage VCC	3.9V	5.5V
Module Voltage Output VO3.3	3.1V	3.5
Module Voltage Output VO1.8	1.65V	1.9
GPIO Voltage	3.1V	3.5V
Storage temperature	-40ºC	95ºC

5.Typical Application Circuit