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I2C Pull Up Resistor Selection

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I am working on one design with Xbee3.
I want to add the option for the I2C communication, but wondering what would be the best pullup reistor values I could use.

I do not find any datasheet that specifiy the requirement.

I have XB3-24Z8PT-J and XB3-24Z8PT models
asked Sep 28 in XBee3 ZigBee by ksonone New to the Community (0 points)

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2 Answers

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Leave the Pull up resistors at defaults for the two lines.

http://cms.digi.com/resources/documentation/digidocs/90002219/#reference/r_class_i2c.htm%3FTocPath%3DMachine%2520module%7CClass%2520I2C%253A%2520two-wire%2520serial%2520protocol%7C_____0
answered Sep 28 by mvut Veteran of the Digi Community (13,472 points)
Thank you, Mvut, for your response. The link you have provided is talking about software implementation.

I am looking for hardware implementation, as every microcontroller has a specific requirement for the I2C hardware implementation.

The following is the one reference document I am looking into.
https://www.ti.com/lit/an/slva689/slva689.pdf
The internal resistors on these pins are set via the firmware to be enabled, pull up or down.
0 votes
I have a I2C air pressure sensor that I am using with the Xbee3. I was able to successfully get it to communicate using 10kohm pull up resistors as follows:

10kohm btw. SDA --> VCC
10kohm btw. SCL --> VCC

Even using the I2C settings via micropython and noting the "automatic" pin settings I still had to add the external pullup resistors to make the sensor work properly.
answered Sep 29 by backpacker87 New to the Community (5 points)
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