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CC2650: I2C PullUp Resistors on Dio4 and Dio5 in I2C Mode

Part Number: CC2650
Other Parts Discussed in Thread: TMP007,


I'm trying to establish an i2C connection to an LSM9DS1 3-Axis motion Sensor. I started with trying to open an I2C Transfer with the TMP007 Example and the CC2650 as a Master Read. I can not see at least the CC2650 sending the Slave address over I2C Bus. I read in the datasheet from the LSM9DS1 that i need Pullup resistors for I2C connection.

I was looking in the Datasheet for the CC2650 but i could not find information about the value of the internal PullUps at DIO4 and 5 wether  pullup is enabled in I2C mode or not.

Do i need external Pullup for I2C Transfers with the CC2650 and what value?

best regards


  • Hi Kai,

    GPIO configurations are capable of using weak internal pullup resistors but the I2C peripheral does not rely on these to drive the communication interface.  Thus external pullup resistors should be used.  The optimal values should be defined by the slave device, or you could attempt using common I2C pullup values such as 2.2 or 4.7 kOhm.