Serial Ethernet HLK-RM04 RS232 RS485 Module for IOT smart home wireless ethernet wifi module data transmission

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  • 1-999 Pieces
    US $10.90
  • >=1000 Pieces
    US $9.90
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Shipping fee:
Depends on the order quantity.
Lead Time:
5 day(s) after payment received
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Quick Details
Model Number:
Logic ICs
Brand Name:
Place of Origin:
Guangdong, China (Mainland)
WiFi working mode:
AP, Client, Repeater, Bridge, Router
RM04 wifi module:
TTL 3.3V
Ethernet port:
two RJ45 port
Main Chipset:
other function:
Cloud/remote control p2p function
Uart port:
Two RS232 ports
Antenna type:
Internal/built-in antenna
Dissipation Power:
5V 150mA
Wireless Control

Packaging & Delivery

Selling Units:
Single item
Single package size: 
10X8X6 cm
Single gross weight:
0.3 kg
Package Type:
1.Standard exported package . 2.Packing list: one HLK-RM04-I module,test board , 5V /1A power supply and antenna.
Lead Time :
Quantity(Piece) 1 - 1000 >1000
Est. Time(day) 5 To be negotiated


 HLK-RM04 with cloud/remote control/p2p function, can realize the remote control thousands miles away. This module has two RS232 ports, two RJ45 ports, with internal/built-in antenna.



Product Description


 This product has two types, with external antenna and internal antenna. Here is internal antenna module, if want external antenna module, please kindly mark out, thanks!







RM04 wifi module: TTL 3.3V         

 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.



1.Serial to WIFI,serial to Ethernet, Ethernet to WIFI, multi functional module,serial sever module,make your serial device easier to access to the network,full transparent two-way data transmission, ensure maximum limit usability and compatibility.

2. Module is integrated 10/100M adaptive Ethernet interface, serial communication baud rate up to 230.4Kbps.

3. With the world's top network chip suppliers Ralink program ,raw materials are used the TDK / / Murata big manufacturers to lay a stable and reliable basis.

4. Reliable system core, applies for safety and long-running system

5.Dimension:40*29mm(smaller than 0ne-third of credit card)

6. Operating temperature: -25~75°C.   

7. Built-in 360M MIPS CPU, 16M RAM and 4M FLASH and wireless baseband and RF front-end, and a variety of peripheral bus. 8.Have CE and FCC certification,support IEEE 802.11 b/g/n,support transparent transmission mode.

9. Support the vast majority of WIFI encryption methods and algorithms, WEP/WAP-PSK/WAP2-PSK/WAPI,encipher type: WEP64/WEP128/TKIP/AES

10. Provide AT + instruction set configuration, providing friendly Web configuration page, configured through the Web.

11. Support built-in onboard antenna and external antenna.

12.Support wireless AP mode and Station mode, the real hardware AP,support all the WIFI connection of iphone and android system and so on ,support AP and station online at the same time.

13. Optional TCP Server/TCP Client/UDP work mode, support lots of Network protocol: TCP/UDP/ARP/ICMP/HTTP/DNS/DHCP. 14. Support DHCP to automatically obtain IP, support the device to assign IP when the module works in AP mode.

15.Serial rate is adjustable, the maximum one is up to 230400.

16. Strong technical support, provide customized needs.  


Other Parameters

Status indicator  

Environmental standard Operating temperature:-20-70 Centigrade

Operating humidity:10%-90%RH(noncondensing)

Storage temperature:-40-80 Centigrade

Storage humidity:5%-90%RH(noncondensing)

Additional properties Frequency bandwidth



Features: Full function of wireless router:

Support 5 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.


Packaging & Shipping


Packaging Details

Unit Type:

lot (1 pieces/lot)

Package Weight:

0.500kg (1.102lb.)

Package Size:

10cm x 8cm x 6cm (3.94in x 3.15in x 2.36in)




International Shipping:

1. WORLDWIDE SHIPPING. (Except some countries and APO/FPO)

2. We only ship to confirmed order addresses. Your order address MUST MATCH your Shipping address.

3. SERVICE TRANSIT TIME is provided by the carrier and excludes weekends and holidays. Transit times may vary, particularly during the holiday season.

4.If you have not received your shipment within 30 days after payment, please contact us. We will track the shipment and get back to you as soon as possible.

5. Shipping time:

1) By HK/china post air parcel : Generally, about 20-30 days (Brazil need 30-40 days)

By Express: Generally, about 5-10 working days

2) Most of the countries within 10 to 20 business days. Except West Europe, Africa. (15-30days)




Promised by Seller



1. All major credit cards are accepted through secure payment processor ESCROW..

2. Please check the additional cost with your customs prior to buying.

3. We will declare the custom invoice with lower value in order to save the money for you.

4.Please indicate your requirement, such as payment, shipment, packaging requirement , value of declaration etc. And please leave your email address to us for urgent contact.

5. Our price does not include taxes, VAT, or other hidden charges.



1) Your Feedback is really important to us, please take a few seconds to leave great feedback if you are satisfied with our product or service, thank you so much!!

2) We always offer the best goods and service to you.

3) Please contact us before leaving neutral (3 stars) or negative (1-2 stars) feedback. We will try our best to solve the problem and leave you a happy shopping mood here. Thank you!




1. Refund or replacement request is available only the requests within 1 week after item received & returning the item as the same condition as received.

2. Please contact us to request a return authorization. Your name, auction number, and reason for return should be included in the email. The items returned must contain all original packaging materials.

3. Please repack the item carefully. Items returned will be tested to ensure the defective and then a new replacement will be shipped to you immediately. In the event that a suitable replacement is not available then a refund will be issued. Shipping, handling and insurance fees are non refundable.

4. If the item is found non-defective, the item will be sent back to the buyer at buyers expense. Items returned without RMA number will be refused and returned to the sender. Buyer is responsible for All Return Postage and Shipping Charges. Buyer is responsible for additional shipping costs for items that are returned refused and/or undeliverable. We do not accept any returns without an authorization number on the box or label it is being returned in.

Our Services

About US:

1. We provide technical support and user manual for customers, if you need, please contact us through Aliexpress mail, we will send the software to you by e-mail, some of the software is large, so please leave your available mail to receive them.

2. We are care about our customer. We guarantee 100% customer satisfaction. If your item is not as described or faulty when you receive it we will replace it for you with no additional charge.

3. We guarantee that our products are brand new, official and first-class quality.

4. Please contact us with any comments, questions or suggestions that you may have, we will be happy to assist you.

5. For quality control we do personally inspect for each item before shipment. All items are 100% new and inspected.

6. We hope to develop a strong, long-term, mutually beneficial relationship with you.

7. If you are a seller, we can help you send the products to your customer directly. (Please contact first, thank you)

8. If you are interesting in our products, please send us your order soon





Company Information

Working time

1.Our working time

Monday to Friday:9:00-12:00 14:00-18:00

2.We work on Saturday one week and the next week we will not work, so to confirm we reply your inquiry in time, please kindly send messages to us during Monday to Friday.

My Aliwangwang ID is cn1511300937 or cn1501632257, you can just chat with me through it or leave messages for me.

3.My skype is winniewan2014, you can also add me to chat about the product.

4.Our technical staff also has skype, please kindly contact me when have technical problems, I will help you to chat with our technical staff.