RE: nRF5340 - TWIM driver not initialized

Gabriele — Mon, 27 Jul 2020 08:54:11 GMT

Hi Simon,

from Zephyr Slack channel I got the answer.
They stress out the fact that we have external ADCs in drivers/adc and external GPIOs in drivers/gpio, so we should be able to have external DACs in drivers/dac.
The specific problem was the init priority value of the DAC, which was lower than for I2C and within the same level (POST_KERNEL). I solved using a larger value.

Best regards,
Gabriele

RE: nRF5340 - TWIM driver not initialized

Simon — Sat, 11 Jul 2020 22:38:26 GMT

I think DAC80501Z should be under zephyr\drivers\sensor, since it is a separate device not integrated into a microcontroller.

Let me try to explain. The drivers in e.g. ncs\v1.3.0\zephyr\drivers\dac, ncs\v1.3.0\zephyr\drivers\adc or ncs\v1.3.0\zephyr\drivers\spi are linked to soc specific drivers. E.g. for the spi driver spi_nrfx_spim.c:

ncs\v1.3.0\zephyr\drivers\spi\spi_nrfx_spim.c →
ncs\v1.3.0\modules\hal\nordic\nrfx\drivers\src\nrfx_spim.c

For your device, this direct linking is not possible, it has to go through three steps:

zephyr/drivers/sensors/dac8050 →
ncs\v1.3.0\zephyr\drivers\spi\spi_nrfx_spim.c or ncs\v1.3.0\zephyr\drivers\i2c\i2c_nrfx_twim.c →
ncs\v1.3.0\modules\hal\nordic\nrfx\drivers\src\nrfx_spim.c or ncs\v1.3.0\modules\hal\nordic\nrfx\drivers\src\nrfx_twim.c

So that's the reason I think it should be placed in zephyr\drivers\sensor. I have not looked into your errors, but the placement may be the reason.

However, I am not 100% sure about this, you could ask here and get the perspective from some other Zephyr developers.

Best regards,

Simon