Help with using TWI with the NRF52832 (SES studio)

RE: Help with using TWI with the NRF52832 (SES studio)

MartinBL — Tue, 12 Dec 2017 14:14:02 GMT

to this:

switch (p_event->type)
{
    case NRF_DRV_TWI_EVT_DONE:
        if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_RX)
        {
            data_handler(m_sample);
        }
        m_xfer_done = true;
        break;
	case NRF_DRV_TWI_EVT_ADDRESS_NACK:
		/**************************************
		 * Handle this case and/or check if your code hits this point with a debugger
		 **************************************/
        break;
    case NRF_DRV_TWI_EVT_DATA_NACK:
		/**************************************
		 * Handle this case and/or check if your code hits this point with a debugger
		 **************************************/
        break;
    default:
        break;
}

RE: Help with using TWI with the NRF52832 (SES studio)

MartinBL — Tue, 12 Dec 2017 14:13:57 GMT

Expand the content of your TWI event handler from this:

switch (p_event->type)
{
    case NRF_DRV_TWI_EVT_DONE:
        if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_RX)
        {
            data_handler(m_sample);
        }
        m_xfer_done = true;
        break;
    default:
        break;
}

RE: Help with using TWI with the NRF52832 (SES studio)

MikeLemon — Sat, 09 Dec 2017 22:05:08 GMT

Hi sorry for the late replay what do you mean by implementing those cases in the event handler? How should I modify the code for that?

And yeah the wiring are correct as I've ran the I2C device scanner example and it manager to read the correct address|!

RE: Help with using TWI with the NRF52832 (SES studio)

MartinBL — Mon, 04 Dec 2017 14:00:11 GMT

Hi,

You should implement the other two possible cases in your event handler too:

NRF_DRV_TWI_EVT_DONE,         ///< Transfer completed event.
NRF_DRV_TWI_EVT_ADDRESS_NACK, ///< Error event: NACK received after sending the address.
NRF_DRV_TWI_EVT_DATA_NACK     ///< Error event: NACK received after sending a data byte.

If your TWI bus of some reason is misbehaving you won't get a NRF_DRV_TWI_EVT_DONE event, and hence m_xfer_done will never be set to true and you will be stuck in the while loop. If you implement the other cases you can also debug and check whether your sensor responds at all. Make sure to check and double check your wiring.