User's Manual

User Manual of HC-42 Bluetooth Serial Port Communication Module G
athering information and Carrying Dreams
Website：
http://www.hc01.com
Guangzhou HC Information Technology Co., Ltd
Address: Room 608, No.19, Jiangong Road, Tianhe Science Park, Tianhe District, Guangzhou City, Guangdong Province
Technical customer service QQ: 445253184 Sales hot line: 020-8408-3341
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①: When the module is connected to the MCU with the power supply system of 3.3V, the serial ports can be cross -
connected. (The RX of the module is connected to the TX of the MCU, and the TX of the module is connected to the RX of
the MCU)
②: When the module is connected to an MCU with a power supply system of 5V, a 200Ω~1KΩ resistor can be
connected in series to the RX pin end of the module and then to the TX pin of the MCU. The TX pin of the module is
directly connected to the RX pin of the MCU, without connection to the resistor in series. (Note: Users are required to
confirm that the MCU used recognizes the voltage of about 3.0V as high level, otherwise, a 3.3V/5V level conversion
circuit is required.)
Note:
It must be noted that the module can be connected to 3.3V (3.0~3.6V) power supply only, instead of 5V. Direct
connecting to 5V will result in damage to module. 5V power supply must be reduced to 3.3V through LDO before
powering on the module.
2.3 Connection between module and mobile phone
HC-42 supports connection to and communication with handset devices using Android 4.3 system and
above.IsBLE Android serial port helper required for communication test.
HC-42 supports connection to and communication with handset devices using iPhone 4S system and
above. For communication test, it requires downloading and installing Lightblue Bluetooth Helper in APP Store
for software connection (other serial port software supporting BLE Bluetooth can also be used).
Module UUID is set forth below:
Search UUID: FFF0 Service UUID: FFE0 Transparent data transmission UUID: FFE1