TWI communication failes after soft reset

RE: TWI communication failes after soft reset

Vidar Berg — Wed, 18 Dec 2019 09:11:45 GMT

Hi Christian,

Glad to hear that you found the problem. Is it possible that you may have had an ongoing TWI transaction when you initiated DFU, and that is why the bus gets "stuck"? Or maybe the same IOs are used for something else in DFU mode? Anyway, I don't see any drawbacks in enabling this option.

Best regards,

Vidar

RE: TWI communication failes after soft reset

chrizz — Tue, 17 Dec 2019 12:54:43 GMT

Vidar, thanks you for your efforts so far.

We meanwhile figured out that enabling the bus clearing procedure during init (clear_bus_init=true in nrf_drv_twi_config_t ) solves the problem. (similar to this issue)

This problem wasn't present when we were using TWI in blocking mode only. But after switching to PPI based (non-blocking) mode it obviously seems to be necessary (in our setup) to clear the bus on init. I assume the slave starts "talking" with the first clock signal (after soft reset) und therefore it disturbs nrf_drv_twi_tx().

Best regards

Christian

RE: TWI communication failes after soft reset

Vidar Berg — Mon, 16 Dec 2019 17:10:27 GMT

Thanks for confirming the SDK version. Is the driver configured in blocking or non-blocking mode (TWI master) and how is it powered, is it through a GPIO pin?

Regards,

Vidar

Edit: No longer relevant, but just to clarify that by "and how is it powered, is it through a GPIO pin?" I meant to ask if the sensor was powered through another GPIO pin.

RE: TWI communication failes after soft reset

chrizz — Mon, 16 Dec 2019 16:47:50 GMT

[quote userid="4240" url="~/f/nordic-q-a/55569/twi-communication-failes-after-soft-reset/225658"]Do you know if the error is returned from the nrf_drv_twi_tx() function or if it's notified through your TWI callback?[/quote]

It seems likes nrf_drv_twi_tx() does not return.

[quote userid="4240" url="~/f/nordic-q-a/55569/twi-communication-failes-after-soft-reset/225658"]Also, are you using the TWI driver from the SDK, or your own?[/quote]

I'm using the driver from the SDK (12.2.0)

Regard

Christian

RE: TWI communication failes after soft reset

Vidar Berg — Mon, 16 Dec 2019 13:31:39 GMT

Hi Christian,

The application's reset handler will re-load everything to RAM on before entering main(), so I don't think that's the issue. Do you know if the error is returned from the nrf_drv_twi_tx() function or if it's notified through your TWI callback? Also, are you using the TWI driver from the SDK, or your own?

Best regards,

Vidar