The EBYTE E104-2G4U04A is a compact USB plug-and-play BLE 4.0 dongle module based on the TI CC2540F256 SoC (8051 core), featuring an on-board PCB antenna, -94dBm receiving sensitivity, and a wireless communication range of up to 60 meters over the 2.4GHz ISM band, designed to add seamless low-energy Bluetooth connectivity to PCs, industrial gateways, and embedded systems.
| Parameter Category | E104-2G4U04A Technical Specifications |
|---|---|
| Core Processor / SoC | Texas Instruments CC2540F256 (Built-in 8051 microcontroller core) |
| Bluetooth Version | Bluetooth Low Energy (BLE) 4.0 standard compliant |
| Frequency Band | 2.402 GHz to 2.480 GHz (Industrial ISM Band) |
| Receiver Sensitivity | -94 dBm |
| Max Transmission Range | Up to 60 meters (Line-of-sight in open, clear outdoor environments) |
| Physical Interface | Standard USB Type-A (Plug-and-Play) |
| Antenna Configuration | On-board, high-performance printed PCB antenna |
| Flash Memory Capacity | 256 KB Flash (Supports user firmware customization) |
| Operating Voltage | Standard 5V DC (USB bus-powered) |
| Operating Temperature | Minus 40 to plus 85 degrees Celsius (Industrial grade) |
The E104-2G4U04A is a compact BLE 4.0 USB dongle designed and manufactured by Ebyte, based on the TI CC2540F256 SoC (8051 core). It features a high-performance PCB on-board antenna, USB plug-and-play connectivity, and operates across the 2.402–2.480GHz ISM band. With a receive sensitivity of -94dBm and a communication range of up to 60m in open environments, it is ideal for adding Bluetooth Low Energy connectivity to PCs, industrial gateways, and embedded systems.
USB Plug-and-Play
No external power or driver complexity — connects directly to any USB host.
-94dBm Sensitivity
High receive sensitivity for reliable BLE links in complex RF environments.
TI CC2540 SoC
256KB Flash + 8KB SRAM; programmable 8051 core for custom BLE firmware.
60m Open-Air Range
Tested at 2.5m antenna height, 250kbps air rate in clear open area.
Technical Specifications
| IC / Chip | TI CC2540F256RHAR (QFN40) |
|---|---|
| Core | 8051 MCU |
| Flash / SRAM | 256KB Flash / 8KB SRAM |
| Protocol | Bluetooth Low Energy (BLE) 4.0 |
| Frequency Range | 2.402 – 2.480GHz (ISM band) |
| Transmit Power | +4dBm (max) |
| Receive Sensitivity | -94dBm @ 250kbps air rate |
| Communication Range | 60m (open area, antenna height 2.5m) |
| Interface | USB (pin spacing 1.27mm) |
| Antenna | PCB on-board antenna |
| Power Supply | USB bus-powered |
| Dimensions | 59 × 18mm (with case) |
| Weight | 8.8g ± 0.1g |
| Data Updated | April 2026 |
Product Details
Practical Application Scenarios
1. Industrial Gateway BLE Data Aggregator Node
In modern factory automation, host computers and legacy industrial gateways often lack standard wireless protocols. Inserting the E104-2G4U04A USB dongle directly upgrades the gateway with BLE 4.0 capabilities. The module acts as a centralized collector, gathering diagnostic telemetry from nearby battery-powered Bluetooth sensors (such as vibration and temperature monitors mounted on rotating motors) and piping the parsed data into local SCADA setups over USB.
2. Clinical Bedside Monitor Data Telemetry
In smart healthcare systems, medical-grade wearables continually measure patient heart rate and oxygen saturation. The E104-2G4U04A can be inserted into bedside nurse stations or clinical PCs. Utilizing its high sensitivity of -94dBm, it reliably aggregates health telemetry over its 60m range, preventing cable clutter around patients while securely transferring data over low-latency BLE links.
3. Wireless Protocol Sniffing and Debugging
Embedded hardware engineers regularly need to capture and evaluate OTA (Over-The-Air) transmissions from peripheral devices. By flashing packet-sniffer firmware onto the TI CC2540 system, this USB dongle acts as a reliable development tool. It monitors BLE advertising packets and data exchanges from target hardware modules (such as remote control nodes), feeding the raw captures into computer analysis software.
4. Proximity-Based Access Control for HMIs
In high-security industrial facilities, machine-operator verification is critical. The E104-2G4U04A can be integrated into industrial touchscreens and HMI terminals. It actively monitors the Received Signal Strength Indicator (RSSI) of employee-worn BLE beacons or smartphones. As a qualified operator approaches or leaves the machinery, the terminal automatically logs the user in or locks the control screen, boosting facility safety.
FAQ Section
1. Can the E104-2G4U04A be used as a BLE packet sniffer for protocol analysis?
Yes, because the dongle is built on the classic TI CC2540F256 platform, it can be flashed with standard packet analyzer firmware (such as the TI SmartRF Packet Sniffer firmware). This turns the USB module into a dedicated 2.4GHz BLE sniffer, enabling embedded developers to capture, inspect, and debug raw Bluetooth wireless packets in real time.
2. Is this module plug-and-play, or do I need to install custom drivers?
The E104-2G4U04A enumerates as a standard Virtual COM Port (VCP) or USB CDC/HID device depending on the specific firmware programmed on the internal CC2540 SoC. Under standard EBYTE serial communication firmware, it is immediately recognized by modern operating systems (including Windows, Linux, and macOS) without requiring complex external drivers, enabling easy UART-to-USB serial communication.
3. How does the PCB on-board antenna perform compared to an external antenna?
The integrated PCB antenna on the E104-2G4U04A is fine-tuned for the 2.402 to 2.480GHz frequency range, providing an extremely compact form factor without external parts. While an external antenna is ideal for long ranges, this internal PCB design offers a highly efficient, space-saving radiation pattern that reliably achieves up to 60 meters of line-of-sight communication.
4. What tools are required if I want to write and flash custom firmware onto the module?
Since the module is powered by the TI CC2540 SoC, custom software development can be executed using the IAR Embedded Workbench for 8051 compiler alongside the official TI BLE-STACK SDK. To program the compiled binary onto the module, developers can connect a standard CC Debugger to the programming interface pins located on the dongle's PCB.
