How to set I2C slave address?

RE: How to set I2C slave address?

Avadacadabara — Wed, 04 Aug 2021 07:48:35 GMT

Thanks Jared!

RE: How to set I2C slave address?

Jared — Wed, 04 Aug 2021 07:29:42 GMT

Yes
Correct
Correct

I suggest reading the documentation for the driver and the peripheral. I also recommend that you try the twi_scanner example and probe the SCL and SDA line with either an oscilloscope or a logical analyzer. I think it would help you understand how the driver works.

best regards

Jared

RE: How to set I2C slave address?

Avadacadabara — Wed, 04 Aug 2021 04:36:29 GMT

Hi Jared,

Sorry for late reply, I've been working on TWI and TWIS communication.

Here are few more points I wish to confirm:

When "nrf_drv_twi_tx" processed, slave "TWIS_EVT_WRITE_REQ" will be called.
When slave address is set to 0x10, I don't have to implement the address to fit read/write application since nrf_drv_twi_tx/nrf_drv_twi_rx will fill the last bit automatically
ACK bit will be sent automatically by slave

Thanks

RE: How to set I2C slave address?

Jared — Mon, 26 Jul 2021 08:05:11 GMT

Hi,

[quote user=""]Should I initialize I2C with TWIS instance?[/quote]

Yes

[quote user=""]How do I suppose to set the slave address[/quote]

The slave address should be sent to the master after the master sends a read request. The read request event TWIS_EVT_READ_REQ is then generated. The TWIM with eeprom shows how this should be done in the eeprom_simulator.c file.

[quote user=""]

If I were use several NRF52s as slaves, how do I suppose to set each address? Does the 7 bits fully customizable?

[/quote]

Yes almost. There are some reserved addresses but other than that, you can pretty much set it to what you like.

[quote user=""]

Perhaps I just need to implement this part to initialize TWIS?

[/quote]

That's enough to initialize it but you have to implement a callback handler that reacts to requests from the Master etc.

regards

Jared