HLK-RM04 – Wi-Fi Serial Transceiver Module (ESP8266 Based)

Key Features

• Integrated ESP8266 Wi-Fi SoC with TCP/IP stack
• UART interface for easy microcontroller/host communication
• Supports AP / STA / AP+STA modes
• Configurable via AT commands
• Compact PCB module with antenna and pins
• Works with 3.3 V logic (level shifting needed for 5 V hosts)
• Low power consumption in sleep modes

Technical Specifications

• Model: HLK-RM04
• Wi-Fi Standard: IEEE 802.11 b/g/n
• Frequency: 2.4 GHz
• Interface: UART (TX, RX, GND, VCC)
• Operating Voltage: 3.3 V DC
• Logic Level: 3.3 V
• Operating Modes: Station (STA), Access Point (AP), AP+STA
• Antenna: PCB or external (variant dependent)
• Security: WEP, WPA/WPA2
• Protocols: TCP, UDP, HTTP, MQTT (module dependent)
• Dimensions: Compact board (module dependent)

Applications

• IoT devices and home automation
• Wireless sensor networks
• Remote control and telemetry over Wi-Fi
• Smart switches and appliances
• Wi-Fi data logging and monitoring
• Embedded systems requiring wireless connectivity

Package Includes

• 1 × HLK-RM04 Wi-Fi Serial Module