The **MH55TAG-R** is a specific electronic sub-assembly, typically identified as a **RFID / NFC Digital Tag** or a **Smart Electronic Shelf Label (ESL)** module. These devices are commonly used in retail environments or logistics for dynamic price updating and inventory management. --- ### Core Electronic Components The MH55TAG-R functions as a low-power wireless communication device. Below are the primary electronic parts integrated into this module: | Component | Function | | :--- | :--- | | **Microcontroller (MCU)** | The "brain" of the tag, usually an ultra-low-power ARM Cortex-M series or proprietary SoC (System on Chip). | | **RF Transceiver** | Handles wireless communication (typically 2.4GHz Zigbee, BLE, or proprietary protocols) to receive updates from a central gateway. | | **E-Paper Display (EPD)** | The visual interface. It uses electrophoretic technology to retain an image without consuming power. | | **NFC Controller** | Allows the tag to be read or programmed via a smartphone or handheld industrial scanner at close range. | | **Power Management IC** | Manages the voltage levels between the battery and the sensitive E-ink display circuitry. | | **Coin Cell Battery** | Usually a CR2450 or similar, designed to last 5–10 years due to the bistable nature of the display. | --- ### Key Technical Specifications Modern tags like the MH55 series typically feature the following technical characteristics: * **Display Technology:** Black/White/Red or Black/White/Yellow 3-color E-Paper. * **Communication Protocol:** IEEE 802.15.4 (Standard for low-rate wireless personal area networks). * **Operating Temperature:** 0°C to 50°C (standard) or -25°C to 30°C (freezer versions). * **Security:** AES-128 encryption for secure data transmission between the server and the tag. --- ### Architectural Layout 1. **Antenna Layer:** A PCB-trace antenna or a small ceramic antenna tuned for 2.4GHz and a coil antenna for NFC (13.56MHz). 2. **Logic Board:** A multi-layer PCB housing the SMD (Surface Mount Device) components. 3. **Encapsulation:** A rugged plastic housing (IP67 rated in some variants) to protect the electronics from dust and moisture. ---