Can nRF52 SDK TWI master write a series of registers

[guraaf]

I want to save precious CPU cycles by writing 40 i2c (TWI) registers in one shot. Can I somehow set up the TWI master to write 40 registers (each 16-byte address with 8-bit data)?

Further, can this be done for two slave devices with two different slave addresses? If not, then I can split it per device. But I am hoping that I don't have to babysit the register writes one-by-one and waste cycles on interrupts and programming each register one at a time.

Any pointers or tips?

[Jørgen Holmefjord]

Hi,

nrf_drv_twi_tx take a pointer to the data, p_data, and a length parameter indicating the lenght of the data. The transfer function support a length up to 256 bytes. The code snippet in the TWI master documentation shows how this is done. It is also possible to trigger a transfer directly from RAM using EasyDMA and PPI.

It is not possible to transfer to multiple devices connected to the same bus simultaneously, but you can initialize both TWI instances available on the nRF52832, and start one transfer on each instance.

You will have to check the datasheet of the device you are interfacing, if it support this method of writing.

Best regards,

Jørgen