NRF_DRV_TWI_INSTANCE

RE: NRF_DRV_TWI_INSTANCE

Simon — Mon, 15 Oct 2018 13:06:07 GMT

You have to include the header file nrf_drv_twi.h at the top of the main file, in addition to adding the location to the path (see this link). Then you must add nrf_drv_twi.c to your project, by adding it in the Project Explorer window to the left. If you encounter any more errors like this, just follow these steps.

I would recommend you to look at one of the provided TWI examples in the sdk, for example the TWI Sensor Example. Then you can see what files needs to be included for the different functions used.

RE: NRF_DRV_TWI_INSTANCE

Sunil vignesh — Fri, 12 Oct 2018 09:22:36 GMT

Hi,

I just enable

#define TWI0_ENABLED 1

#define TWI_ENABLED 1

#define NRFX_TWI_ENABLED 1

#define NRFX_TWI0_ENABLED 1

now the NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID) error not came but

it shows

RE: NRF_DRV_TWI_INSTANCE

Simon — Thu, 11 Oct 2018 08:11:48 GMT

Let me try to explain why it fails.

First NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID); is called in main, with an argument of 0
Then inside nrf_drv_twi.h the following line will be called

#define NRF_DRV_TWI_INSTANCE_(id)   NRF_DRV_TWI_INSTANCE_ ## id

It looks for the definition of NRF_DRV_TWI_INSTANCE_0, but as you can see in the code snippet down below, it is grayed out. This is because NRFX_TWI0_ENABLED is not set to 1

Inside the file apply_old_config.h NRFX_TWI0_ENABLED is defined in the following manner

#define NRFX_TWIM0_ENABLED  (TWI0_ENABLED && TWI0_USE_EASY_DMA)

If you enable both of these definitions inside sdk_config.h, it should be fine

Something that may cause confusion is that there is two different kinds of definitions in the sdk_config.h file (e.g. TWI_ENABLED and NRFX_TWI_ENABLED). If the former is present (legacy), then the other definitions will be ignored.

Hopefully this made sense.

Best regards, Simon