HLK-RM04 is a new low-cost embedded UART-ETH-WIFI module (serial port - Ethernet - Wireless network) developed by Shenzhen Hi-Link Electronic Technology 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.

Features:Full function of wireless router:
Support5 types of work mode:AP, Client, Repeater, Bridge, Router
AP mode- Default work mode. In this mode, the device works as a wireless access point, support for plug-and-play, and no configuration needed.
Router mode-In this mode, the device is equivalent to a wireless router, wired interfaces can be used as WAN, wireless used as LAN. Multiple wireless clients can share a broadband line to search the Internet.
Repeater mode -Use the radio relay function of the device, achieve the radio signal repeat and amplified, and form a new radio coverage area, ultimately attain the purpose of extending the coverage of the wireless network.
Bridge mode-With the Bridging function of equipment, firstly, the module RM04 establish a wireless connection with the front-end wireless network itself ,then sending the wireless signal, at the same time, form a new wireless coverage, signal weak and signal blind spot can be solved effectively.
Client mode -The AP to work in this mode for the main AP is a wireless client, the equivalent of a wireless network card.
Table2-1Technical Specifications
| Network standard | wireless:IEEE 802.11n、IEEE 802.11g、IEEE 802.11b |
| wired:IEEE 802.3、IEEE 802.3u | |
| Wireless transmission rate | 11n: maximum up to 150Mbps 11g: maximum up to 54Mbps 11b: maximum up to 11Mbps |
| Tracks number | 1-14 |
| Frequency range | 2.4-2.4835G |
| Emission power | 12-15DBM |
| Interface | 10/100Mbps LAN/WAN multiplex interface、interface |
| Antenna | |
| Antenna type | Onboard antenna / External Antenna |
| Functional Parameters | |
| WIFI work mode | Client/AP/Router |
| WDS Function | Support WDS wireless bridge connection |
| Wireless security | Wireless MAC address filtering |
| Wireless security function switch | |
| 64/128/152 bit WEP encryption | |
| WPA-PSK/WPA2-PSK、WPA/WPA2 security mechanism | |
| Network management | Remote Web management |
| Configuration file import and export | |
| WEB software upgrade | |
| Serial to Ethernet | |
| Maximum transmission rate | 230400bps |
| TCP connection | Max connection number>20 |
| UDP connection | Max connection number>20 |
| Serial baud rate | 50~230400bps |
| Other Parameters | |
| Status indicator | Status indicator |
| Environmental standard | Operating temperature:-20-70℃ |
| Operating humidity:10%-90%RH(noncondensing) | |
| Storage temperature:-40-80℃ | |
| Storage humidity:5%-90%RH(noncondensing) | |
| Additional properties | Frequency bandwidth optional:20MHz、40MHz,Automatic |
HLK-RM04 MechanicalDimensions is shown in the following picture:

Picture2.Dimensions Unit:mm
The Pin of this product as shown above is defined as follows:
Table2-2 module pin interface
| No. | Function | Direction | Explanation |
| 1 | VDD5V | A | 5 Power input |
| 2 | GND | GND | Power ground |
| 3 | GND | G | Serial sending |
| 4 | 3.3V | I | 3.3V power output |
| 5 | LINK1 | I/O | Net gape 1 LED indicte |
| 6 | USB_P | USB signal | |
| 7 | USB_M | USB signal | |
| 8 | I2S_SD | I2C DATA/GPIO | |
| 9 | I2S_CLK | I2C CLK/GPIO | |
| 10 | GIOP0 | I/O | Universal GPIO |
| 11 | TXOP1 | I/O | Net gape 1 TX-P |
| 12 | TXON1 | I/O | Net gape 1 TX-N |
| 13 | RXIP2 | I/O | Net gape 2 RX-P |
| 14 | RXIN2 | I/O | Net gape 2 RX-N |
| 15 | RXIN1 | I/O | Net gape 1 RX-P |
| 16 | RXIP1 | I/O | Net gape 1 RX-P |
| 17 | TXON2 | I/O | Net gape 2 TX-N |
| 18 | TXOP2 | I/O | Net gape 2 TX-P |
| 19 | RTS_N | I | All function serial RTS |
| 20 | UART_RX | I | Simple serial RX |
| 21 | UART_TX | O | Simple serial TX |
| 22 | RXD | I | All function serial RX |
| 23 | LINK2 | I/O | Net gape 2 LED I/O indicte |
| 24 | CTS_N | O | All function serial CTS |
| 25 | RIN | I | GPIO |
| 26 | TXD | O | All function serial TX |
| 27 | 1.8V | Power Out | Net gape 1.8V output |
| 28 | VDD5V | Power In | 5V input |
Serial to network parameter configuration
Open the brower:http//www.192.168.16.254,access to the configuration page, configured the parameters through web according to your needs. The information (ser2net.asp) is as follows:

Provide the schematic diagram and pcb diagram
Functions:



Others

