nrf9160 SPI without CSn

RE: nrf9160 SPI without CSn

e-va — Fri, 29 Sep 2023 10:54:44 GMT

Hi,

this is our datasheet https://www.ti.com/lit/ds/symlink/amc3306m25.pdf it looks like the same that you linked in an earier comment.

Best regards

RE: nrf9160 SPI without CSn

Maria Gilje — Fri, 29 Sep 2023 07:25:33 GMT

Hello,

Please share the datasheet for the device you are using so we can be sure that we are working with the same documentation. We need to make sure that the interface used is compatible with both your ADC and the peripheral interface you set up for the nRF9160.

BR,

Maria

RE: nrf9160 SPI without CSn

e-va — Tue, 26 Sep 2023 13:49:42 GMT

Hi,

I can't see how to use I2C for the interface defined in the ADC datasheet. SPI seems a perfect fit.

We have found out in the meantime that we are in fact receiving data using the functions provided by the SDK, however the spi_transceive function does not return after the number of bytes defined in the buffer have been received. It will wait for the CS line to de-assert, which I think is not the intended behavior. Is there a way to receive from SPI only a limited amount of data, regardless of CS line state?

Best regards

RE: nrf9160 SPI without CSn

Maria Gilje — Tue, 26 Sep 2023 08:57:26 GMT

Hello,

I got a second opinion from a colleague, and he pointed out that in the datasheet for AMC3306M25 there is no indication that the ADC supports SPI interface, but does support I2C/TWI interface.

What you need to do is to add an I2C node to your configuration.

I apologize for overlooking the mismatch in interface between your ticket and the datasheet.

Best regards,

Maria

RE: nrf9160 SPI without CSn

Maria Gilje — Mon, 25 Sep 2023 15:55:03 GMT

Hello again,

What is the reason for using NCS v1.9.2? The latest tagged release of NCS is currently v2.4.2. If you are in the starting phase of a project, you should consider to migrate to NCS v2.4.2.

You can delete node properties by adding /delete-property/ name-of-unwanted-property; to the node configuration.

Is this configuration for the ADC or the nRF9160?

If it is for the nRF9160 side: the configuration should be nrf-spim, because the nRF9160 would be the master and the ADC the slave. The SPI master will not need the CSn pin, so that issue is taken care of by switching to nrf-spim. Delete the miso-pin property as described above.

If it is for the ADC: Delete the unwanted properties as described above.

Best regards,

Maria

RE: nrf9160 SPI without CSn

Maria Gilje — Wed, 20 Sep 2023 15:35:17 GMT

Hello,

I have been assigned this ticket, and will get back to you as soon as I can.

Thank you for your patience.

Regards,

Maria