i2c_write_dt returns -5 EN0DEV

RE: i2c_write_dt returns -5 EN0DEV

Håkon Alseth — Tue, 12 Mar 2024 13:32:58 GMT

Hi Niels,

Great to hear that the issue was solved. Hope you have a wonderful day!

Kind regards,

Håkon

RE: i2c_write_dt returns -5 EN0DEV

Niels Redegeld — Tue, 12 Mar 2024 13:29:07 GMT

Okay so it works now, cause on the custom Sensor pcb the pins were labelled wrong. I tried switching the pins before and it didn´t work. So I am pretty sure the internal pullup resistor did the job at fixing the problem.

Thanks for your time

Kind reagrds,

Niels Redegeld

RE: i2c_write_dt returns -5 EN0DEV

Håkon Alseth — Tue, 12 Mar 2024 13:11:06 GMT

Hi Niels,

It will still give a -5, because there is no sensor attached.

Here's a logic analyzer scope, when pull-up has been enabled on SDA/SCL pins, tested with the firmware that you attached:

Kind regards,

Håkon

RE: i2c_write_dt returns -5 EN0DEV

Niels Redegeld — Tue, 12 Mar 2024 12:08:11 GMT

Hi,

I did not have a pullup resistor, so I added that. Thanks.
However the problem is still not solved, it gives the same error.

Kind regards,

Niels Redegeld

RE: i2c_write_dt returns -5 EN0DEV

Håkon Alseth — Tue, 12 Mar 2024 11:59:36 GMT

Hi Niels,

Do you have any external pull-up resistors present on these pins?

If not, can you please add this to the overlay?

&pinctrl {
	i2c0_default: i2c0_default {
		group1 {
			psels = <NRF_PSEL(TWIM_SDA, 0, 26)>,
				<NRF_PSEL(TWIM_SCL, 0, 27)>;
			bias-pull-up;
		};
	};
};

&i2c0 {
    status = "okay";    
    mysensor: mysensor@4c{
        compatible = "st,stts751";
        reg = < 0x4c >;
    };
};

Kind regards,

Håkon

RE: i2c_write_dt returns -5 EN0DEV

Niels Redegeld — Tue, 12 Mar 2024 09:38:41 GMT

Hi,

Yes the state does not change at all. The pins that are defined are pin 26 SCL and pin 27 SDA

Kind regards,

Niels Redegeld

RE: i2c_write_dt returns -5 EN0DEV

Håkon Alseth — Tue, 12 Mar 2024 09:36:39 GMT

Hi Niels,

Do you mean that the SDA/SDC does not change state at all?

Which pins are you using? Ie. what is the pins defined in "i2c0_default"?

Kind regards,

Håkon

RE: i2c_write_dt returns -5 EN0DEV

Niels Redegeld — Tue, 12 Mar 2024 09:33:57 GMT

Hi,

Thank you for your reply, it seems fairly logical but the ack would be received after the MCU sent something. Which means that when i put the I2C bus on the logic analyser I would've seen something at the start. But nothing got sent at all. This makes me think that the error comes from deeper with in cause i already tried before with the sensor already connected.

Kind regards,
Niels Redegeld

RE: i2c_write_dt returns -5 EN0DEV

Håkon Alseth — Mon, 11 Mar 2024 13:36:56 GMT

Hi,

[quote user=""]I currently am connected to a logic analyzer so the adresses and stuf doesn't matter. When i flash the code i2c_write_dt returns -5 (EN0DEV) And I am wondering what this actually means.[/quote]

If there is no sensors connected to the I2C SDA/SCL pins, then you will not get an ACK from a sensor, and thus the API will report -EIO (-5) back.

This is expected behavior when there's no ACK received over the bus.

Kind regards,

Håkon