Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Yusuke — Mon, 30 Sep 2019 13:44:51 GMT

Thanks!

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Kenneth — Mon, 30 Sep 2019 13:43:52 GMT

For TWI I would recommend external pull-up resistors always, then you avoid potential problems with configuration, startup delays, timing etc.

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Yusuke — Sun, 29 Sep 2019 11:26:20 GMT

Any tip?

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Yusuke — Sun, 22 Sep 2019 14:30:54 GMT

> Not sure whether this ships the same way in nRF9160 compatible SDKs.

true.

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Turbo J — Sun, 22 Sep 2019 13:14:53 GMT

It is in nrfx_twim.c from the SDK15.3 that I use here.

Not sure whether this ships the same way in nRF9160 compatible SDKs.

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Yusuke — Sun, 22 Sep 2019 12:46:51 GMT

Where is TWIM_PIN_INIT used? I couldn't find it in my ncs folder

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Turbo J — Sun, 22 Sep 2019 10:51:59 GMT

Not the hardware directly, but the nrfx library does (TWIM_PIN_INIT macro).

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Yusuke — Sun, 22 Sep 2019 09:05:33 GMT

Thanks!

Objective Product Specification v0.7.1, p100

Does MCU automatically set SCL and SDA pins as pull-up pins when I configure TWIM(I2C)?

RE: Does nRF9160 have internal pull-up resistors for I2C(TWIM)?

Turbo J — Sun, 22 Sep 2019 08:48:48 GMT

Look in the PS: Peripherials->GPIO->electrical specifications.

The pullup resistors are unusually small and thightly specified (compared to other MCUs I have flying around here). A pullup beween 11k and 16k is usable for I²C bus in many cases - but it will depend on bus load and -speed.

You want to check signal form with a scope.