EWT104-BT41SP: Low-Cost Dual-Mode Bluetooth Slave Module Test Kit
[EBYTE Logo] ⚙️
Manufacturer: Chengdu Ebyte Electronic Technology Co.,Ltd.
Product Overview
The EWT104-BT41SP is a low-cost dual-mode Bluetooth slave module test kit designed to significantly reduce user development cycles. For detailed information about the EWM104-BT41SP module, please visit the official website to download relevant materials.
Module Features
- Supports BLE 5.4.
- Supports only the slave role.
- Supports SPP and BLE broadcast switching; only one broadcast type is allowed at a time.
- Features a pre-soldered EWM104-BT41SP module.
- Adjustable transmit power, with a maximum of 8dBm.
- All module pins are led out for easy access.
- Offers stable operation and is easy for development.
Figure 1: EWT104-BT41SP Module. The module measures 59.6mm in length and 30.0mm in width. It features the EWM104-BT41SP module, pin headers, a reset button, and indicator LEDs.
Hardware Description
Pin Definition
| No. | Definition | Description | Remarks |
|---|---|---|---|
| 1 | TXD | Serial output pin | 2.54mm pitch header |
| 2 | RXD | Serial input pin | |
| 3 | 3.3V | DC 3.3V input pin | |
| 4 | POWER | Power indicator LED | |
| 5 | RXD | Serial receive indicator LED | - |
| 6 | TXD | Serial transmit indicator LED | - |
| 7 | RESET | Reset button | - |
| 8 | PB6 (WKP) | Enables broadcast when high, enters low-power sleep when low. | - |
| 9 | EWM104-BT41SP | Pre-soldered module | - |
Figure 2: Detailed view of the EWT104-BT41SP module with numbered pin callouts corresponding to the pin definition table.
Quick Start
3.1 Serial Port Tool Configuration
When the module's Bluetooth broadcast is not connected, it operates in AT command mode for configuration and queries. Upon connecting via BLE or SPP, it enters transparent transmission mode, disabling AT commands.
Configure your serial port tool with the default settings: 115200 baud rate, 8 data bits, 1 stop bit, no parity, and no flow control.
Figure 3: Screenshot of SSCOM software showing serial port configuration settings (COM46, 115200, 8, 1, None, None) and available AT commands.
Figure 4: Screenshot of AccessPort software showing similar serial port configuration settings.
Follow the commands specified in section 6.4 and instructions in section 6.2 to send AT commands for module configuration.
3.2 BLE Data Transparent Transmission and Air Configuration
Air configuration is available when connected in BLE mode.
- Open the "nRF connect" app on your mobile device.
- Start scanning for devices and find the device named "CDEBYTE_BLE".
- Connect to the device. You can filter by RSSI to locate the target Bluetooth module signal.
- The broadcast name is "EBYTE BLE".
- After connecting, open the service with UUID 0xFFF0 to proceed with further operations.
Figure 5: nRF Connect app interface showing device scanning, filtering options, and the "CDEBYTE_BLE" device found.
Figure 6: nRF Connect app displaying the connected "CDEBYTE_BLE" device and its services, including "Unknown Service" with UUID 0xFFF0.
Performing Data Transmission Tests:
Mobile App (Phone):
- To receive data via UUID FFF1: Select option ①. Received data will be displayed in area ②.
- To send data via UUID FFF2: Select option ①. Enter the data to send in area ②. Area ③ will echo the sent data.
PC (Computer):
- Send data using a serial terminal program like SSCOM.
Figure 7: nRF Connect app interface showing the "Unknown Characteristic" with UUID 0xFFF1 (for notifications) and UUID 0xFFF2 (for writing). Callouts indicate areas for selecting characteristics and viewing/entering data.
Figure 8: SSCOM software displaying received data (hexadecimal format) from the module and sent data during BLE communication.
Sending AT Commands via BLE (Air Configuration):
- To send AT commands and receive echoes via UUID FFF3: Open option ① to view received data echoes. Open option ② to edit the content to send. Enter the commands in area ③ (note the TEST format). Area ④ displays the command operation results.
- Refer to section 5.1 for password verification.
- AT commands can be sent over the Bluetooth connection for air configuration.
Figure 9: nRF Connect app interface showing the "Unknown Characteristic" with UUID 0xFFF3 (for notifications and writes), with callouts for sending AT commands and viewing results.
Figure 10: SSCOM software showing sent and received data during BLE AT command communication.
Note: Message formats may vary; ignore any extra 0x00 bytes. On iOS devices, long messages might be truncated; limit values to a reasonable length.
3.3 SPP Data Transparent Transmission
- Open an SPP Bluetooth serial app (e.g., a terminal app).
- Search for the Bluetooth name "CDEBYTE_SPP" and connect.
- Filter by RSSI to locate the target Bluetooth module signal.
- The broadcast name is "EBYTE SPP".
Mobile App (Phone):
- Bidirectional transparent data transmission: Receive data.
PC (Computer):
- Send data using a serial terminal program like SSCOM.
Figure 11: SPP app interface showing device scanning, connection to "CDEBYTE_SPP", and data reception.
Figure 12: SSCOM software displaying data transmission and reception logs for an SPP connection.
Revision History
| Version | Revision Date | Description | Maintainer |
|---|---|---|---|
| 1.0 | 2025-08-01 | Initial Version | Lei |
About Us
Sales Hotline: 4000-330-990
Technical Support: support@cdebyte.com
Official Website: www.ebyte.com
Company Address: Building B2, No. 199, Xiqu Avenue, High-tech West Zone, Chengdu, Sichuan Province.
[Chengdu Ebyte Logo] Chengdu Ebyte Electronic Technology Co.,Ltd.
