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Question：What is the recommended value of the pull-up resistor when 1-wire serial communication (UART) is used?
When 1-wire serial communication (UART) is used, it is common when transmission on the target microcomputer side is open drain output.
In this case, since the H level voltage of the transmit data on the microcomputer side depends on the pull-up, when the resistance value of the pull-up resistor is large, the rising waveform of the signal gets dull and a communication error such as FRAMING ERROR may occur.
The recommended value of the pull-up resistor in 1-wire serial communication is about 1K to 4.7K Ohm.
If the resistance value of the pull-up mounted on the board is large, please add a pull-up resistor also on the jig so that the synthesized resistance value falls within the recommended range.
In this case, since the H level voltage of the transmit data on the microcomputer side depends on the pull-up, when the resistance value of the pull-up resistor is large, the rising waveform of the signal gets dull and a communication error such as FRAMING ERROR may occur.
The recommended value of the pull-up resistor in 1-wire serial communication is about 1K to 4.7K Ohm.
If the resistance value of the pull-up mounted on the board is large, please add a pull-up resistor also on the jig so that the synthesized resistance value falls within the recommended range.
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