i2c SDA cannot read acknowledge

RE: i2c SDA cannot read acknowledge

awneil — Mon, 07 Oct 2019 10:49:55 GMT

That's exactly why Nordic provide the SDK - so that you don't have to delve into all the arcane details of register-level programming!

RE: i2c SDA cannot read acknowledge

Lennart — Mon, 07 Oct 2019 07:18:28 GMT

SOLVED It was the GPIO register PIN_CNF. Nobody at my company understand by apply the Nordic doc, but I read out from the example and applied 0x0000060C for the SDA and then the output do not drive high, the device ack works.

Thank's awneil

RE: i2c SDA cannot read acknowledge

awneil — Fri, 04 Oct 2019 08:01:53 GMT

[quote userid="81825" url="~/f/nordic-q-a/52854/i2c-sda-cannot-read-acknowledge/213315"]Devboard: https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52-DK[/quote]

So have you checked that it's not something on the board - external to the nRF52 - that's messing with your I2C lines ... ?

RE: i2c SDA cannot read acknowledge

Lennart — Fri, 04 Oct 2019 07:13:29 GMT

That's a good approach I can run an example application and read out the register configurations.

SI7055 https://www.silabs.com/documents/public/data-sheets/Si7050-1-3-4-5-A20.pdf

Devboard: https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52-DK

RE: i2c SDA cannot read acknowledge

awneil — Thu, 03 Oct 2019 12:56:15 GMT

[quote userid="81825" url="~/f/nordic-q-a/52854/i2c-sda-cannot-read-acknowledge"]By put a 560 ohm in serial to SDA I can see that the device actually send a low level signal, but on the other side, at Nordic SDA the level is still high[/quote]

The I2C lines should never be driven high - so you must have this configured wrong!

I suggest that you start with one of the SDK examples - they will ensure that everything is correctly configured.

The TWI Scanner is the simplest one to start with.

You haven't said what board you're using.

Or what SDK

It would also be helpful to give a link for your sensor.

RE: i2c SDA cannot read acknowledge

awneil — Thu, 03 Oct 2019 12:46:58 GMT

(never mind)