1. Overview
The CH9142 is a double Bluetooth® Low Energy (BLE) to UART bridge controller. It supports BLE host mode, slave mode, and broadcast mode, complying with the BLE 5.0 specification. This controller facilitates serial AT commands and BLE communication configuration in slave mode. Its serial port supports a baud rate of up to 1Mbps and includes MODEM signal support.
In Bluetooth slave mode, parameters such as Bluetooth name and manufacturer information can be configured easily via an APP or AT commands. The two serial ports can independently control their respective Bluetooth modes and statuses. The CH9142 supports two Bluetooth connections to communicate with corresponding serial ports.
2. Features
- Supports master mode, slave mode, and broadcast mode.
- Supports serial port AT configuration and BLE transmission configuration.
- Each of the two serial ports can be set individually for Bluetooth.
- Provides a computer-end BLE virtual serial port driver.
- Compatible with existing serial port software and tools, requiring no secondary development.
- Supports BLE host connection for Windows, Linux, Android, iOS, and other systems.
- Power-off sleep current is 0.3uA.
- Transmission distance: 100 meters.
- Transmit power is adjustable in 8 gears.
- Maximum communication baud rate is 1Mbps.
- UARTs support MODEM communication signals RTS and CTS.
- UARTs support 5, 6, 7, or 8 data bits and 1 or 2 stop bits.
- UARTs support parity check modes: odd, even, no check, space, and mark.
- 32K clock source with optional external crystal oscillator.
- Available in QFN28 square leadless 28-pin package.
3. Specifications
3.1. Electrical Characteristics
3.2. Package Information
The CH9142 is provided in a QFN28 square leadless 28-pin package. Key dimensions are:
- Body size: 4*4mm
- Lead pitch: 0.4mm
- Lead pitch (imperial): 15.7mil
- Description: Quad no-lead 28-pin
4. Applications
The CH9142 is suitable for various applications requiring a bridge between Bluetooth Low Energy and UART serial communication. Its dual BLE and UART capabilities allow for flexible integration into systems needing wireless data transfer to and from microcontrollers or other serial devices.
5. Setup Instructions
5.1. Hardware Connection
- Power Supply: Connect the VCC pin to a stable power supply (refer to electrical characteristics for voltage range). Ensure proper grounding via the GND pin.
- UART Connection: Connect the TXD0/RXD0 and TXD1/RXD1 pins to your microcontroller (MCU) or other serial port devices. If MODEM signals (RTS/CTS) are required, connect RTS0#/TNOW0, CTS0#, RTS1#/TNOW1, and CTS1# accordingly.
- Antenna: Connect an appropriate antenna to the ANT pin for optimal Bluetooth transmission range.
- Clock Source: If an external 32K crystal oscillator is used, connect it to the X32KI and X32KO pins.
- Control Pins: Utilize LED0/RELOAD, SLEEP, LED1, AT1, BLESTA0, and BLESTA1 pins for status indication and control as per your application design.
Refer to the CH9142 Datasheet for detailed pin descriptions and recommended circuit diagrams.
5.2. Software Setup
- Driver Installation: For PC-based applications, install the provided BLE virtual serial port driver.
- Configuration Tools: Use the official WCH tools (e.g., BleUartApp, COMTransmit, VSPD) for initial configuration and testing.
- AT Commands: Configure Bluetooth parameters (e.g., name, manufacturer information, operating mode) using AT commands sent via the serial port.
6. Operating Instructions
6.1. Bluetooth Modes
- Slave Mode: The CH9142 can act as a BLE peripheral, allowing other BLE hosts (e.g., smartphones, computers) to connect and exchange data via its UART interfaces. Parameters can be set via AT commands or a dedicated APP.
- Host Mode: The CH9142 can initiate connections to other BLE peripheral devices.
- Broadcast Mode: The CH9142 can broadcast data packets without establishing a connection.
6.2. Dual UART Operation
The CH9142 features two independent UART interfaces. Each UART can be configured and controlled separately for Bluetooth communication, allowing for simultaneous data exchange with two distinct BLE connections or devices.
6.3. Data Transmission
Once a BLE connection is established, data sent to the CH9142's UART interface will be transmitted over Bluetooth, and data received via Bluetooth will be output through the UART interface. Ensure the baud rate, data bits, stop bits, and parity settings match between the CH9142 and the connected serial device.
7. Maintenance
- Handling: Handle the CH9142 chip with care to avoid physical damage. Use anti-static precautions when handling to prevent electrostatic discharge (ESD) damage.
- Environment: Store and operate the device in a dry environment, away from extreme temperatures, humidity, and corrosive substances.
- Cleaning: If cleaning is necessary, use a soft, dry cloth. Avoid using liquids or abrasive cleaners.
- Firmware Updates: Check the official WCH website periodically for any available firmware updates that may improve performance or add new features.
8. Troubleshooting
- No Power: Verify that the VCC and GND connections are correct and that the power supply is within the specified voltage range.
- No Bluetooth Connection:
- Ensure the antenna is properly connected.
- Check if the CH9142 is in the correct BLE mode (host, slave, broadcast) for your application.
- Verify that the BLE host device is within the 100m transmission range.
- Confirm that the Bluetooth name and other parameters are correctly configured using AT commands or the APP.
- Serial Communication Issues:
- Check for correct TXD/RXD wiring between the CH9142 and the serial device.
- Verify that the baud rate, data bits, stop bits, and parity settings match on both ends.
- Ensure that AT commands are sent with the correct syntax and termination characters.
- If using MODEM signals, confirm RTS/CTS connections and configuration.
- Driver Problems: If using a PC, ensure the correct virtual serial port driver is installed and recognized by the operating system.
9. Warranty and Support
This product is manufactured by WCH. For technical support, detailed documentation, and software tools, please refer to the official WCH website.
9.1. Documentation and Tools
- Datasheet: For comprehensive technical details, refer to the official CH9142 Datasheet available at: https://www.wch.cn/downloads/CH9142DS1_PDF.html
- Tools (BLE to UART): Download the application for BLE to UART communication from: https://www.wch.cn/downloads/BleUartApp_ZIP.html
- Tools (UART): Download the UART communication tool from: https://www.wch.cn/downloads/COMTransmit_ZIP.html
- Tools (VSPD): Download the Virtual Serial Port Driver (VSPD) tool from: https://www.wch.cn/downloads/BleComWin_ZIP.html
- Library: Access the relevant library files from: https://www.wch.cn/downloads/BleUartLib_ZIP.html
9.2. Compliance Information
⚠ WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
