Interfacing two slaves on spi master

RE: Interfacing two slaves on spi master

Jørgen Holmefjord — Thu, 13 Jul 2017 11:05:40 GMT

RE: Interfacing two slaves on spi master

YASH — Thu, 13 Jul 2017 08:26:39 GMT

Hello, i am following the third step, as it is best suited for me, although i am getting an error in the line:-

volatile spi_control_block_t * my_setup = mw_spi_instance.drv_inst_idx;

its saying that "mw_spi_instance" is not declared or is unidentified. As i believe, it is function for nrf52, which is certainly not mapping. If i ma right, can u redirect to the correct replacement of this for my nrf51 as i m working on nrf51422.

Thank you in advance.

RE: Interfacing two slaves on spi master

Jørgen Holmefjord — Wed, 12 Jul 2017 09:27:36 GMT

Hi,

The SPI master driver in our SDK does not support switching SS pin for use with multiple devices. You got a couple of alternative options to interface multiple chips:

Use two different SPI instances. The nRF51 series support up to two SPI master instances running simultaneously.
Set the SS pin to NRF_DRV_SPI_PIN_NOT_USED and control the SS pin yourself using the GPIO abstraction API functions.
Use the method suggested by this user, to change the SS pin in the SPI master driver. Note that I have not tested this, but the principle should work.

Best regards,

Jørgen