I2C implementation in Nrf NCS SDK 1.7.1

[hiteshk014]

Hi,

We want to explore I2C examples in nCS SDK 1.7.1

Can you please enlist all the examples having I2C implementation.

also want to add I'm referring to I2C API's mentioned in this link & i2c.h from this path in nCS 1.7.1 (\nCS\v1.7.1\zephyr\include\drivers)

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/reference/peripherals/i2c.html 

kindly suggest the sample example we should refer for the I2C peripheral development.

Thank you,

[Priyanka]

Hi Hitesh,

We are on low staffing since it's the holiday month. Sorry for the delayed response.

This thread could help you for the issue.

Regards,

Priyanka

[hiteshk014]

Hi Priyanka,

I need a sample example of Master-slave I2C protocol,

can you please share some input,

didn't get from above example 

Thanks

[Priyanka]

Hi Hitesh,

We do not have much examples for the I2C in the nRF Connect SDK. However, one of our colleague has developed this sample which might be of help.

Regards,

Priyanka

[hiteshk014]

Thank you Priyanka for quick response,

One question on how do we configure master / slave in I2C can you have a basic description ? 

[Priyanka]

Hi Hitesh,

We have this Guide which can help you.

Regards,

Priyanka

[hiteshk014]

Hi Priyanka,

This tutorial helped significantly, thank you very much for helping, 

We want to know 3 things about data transfer and configuration in i2c.

1. Changing clock frequency

if we need to change clock frequency is it sufficient to pass respective speed configurations in configure as shown below, or can you please share inputs for changing clock frequency in I2C?

i2c_configure(m_i2c_dev, I2C_SPEED_SET(I2C_SPEED_FAST) | I2C_MODE_MASTER);

2. I want to have multiple slave configuration and single master in I2C, I am attaching overlay file of master having multiple slave configurations & slave overlay which will be common across all the slave device, created as per my understanding, please provide your inputs what all configurations are needed for having multiple slave configuration. I am using very same slave example mentioned here in this Guide

3. I want to transfer 16 bit data through i2c bus I am referring to following api i2c_write

int i2c_write(const struct device *dev, const uint8_t *buf, uint32_t num_bytes, uint16_t addr)

if we see buf Memory pool from which the data is transferred it is uint8_t, I want to know common practice nordic recommendation to transfer 16 bit data and a values having signed int.

Thank you,

 

bl653_dvk (Master).overlaybl653_dvk (Slave).overlay

[Priyanka]

Hi Hitesh,

hiteshk014 said:

1. Changing clock frequency

Yes, in order to change the clock frequencies, it's sufficient to pass the speed configurations as mentioned in the documentation. 

hiteshk014 said:

2. I want to have multiple slave configuration and single master in I2C

Your overlay file seems good. You can connect up to 127 slaves on a single I2C/TWI bus. You can refer to this GitHub page.

hiteshk014 said:

3. I want to transfer 16 bit data through i2c bus I am referring to following api i2c_write

I don't think this is possible since the i2c_write() expects a uint8_t pointer .

Regards,

Priyanka 

[hiteshk014]

Hi Priyanka,

I want to know more detail about slave implementation in the mentioned demonstration,

in this Guide why are we using nRFx  TWIS Driver, master is done using zephyr api's but slave is implemented using nrfx ?

Can we have any slave device demonstration which doesn't uses nRFx TWIS driver.

Thank you

Regards,

[Priyanka]

Hi Hitesh,

This is mentioned in the initial portion of the Guide.

"no Zephyr I2C/TWIS Slave Driver supports Nordic I2C/TWI Slave hardware to date. As a result, the TWIM software will use the Zephyr i2c driver, and the TWIS software will use the nRFX driver (NRFX_DRV) paradigm"

Regards,

Priyanka