BNO080 SH-2 over TWIM

RE: BNO080 SH-2 over TWIM

WQvist — Fri, 25 Sep 2020 08:04:48 GMT

Did you ever get it to work?

RE: BNO080 SH-2 over TWIM

aplatts — Tue, 24 Mar 2020 10:37:20 GMT

Hi, it does respond to its appropriate address now I've capture the event using the event handler. I'm rebuilding the code and have connected the hardware interrupt from the BNO080, to check its in a ready state before sending data.

I'll come back with the code so it can be shared once its working.

RE: BNO080 SH-2 over TWIM

Edvin — Tue, 24 Mar 2020 10:26:35 GMT

Have you looked in the datasheet for your sensor? What addess is it supposed to be on? And have you analyzed the TWI wires? Does the data there look like it is supposed to?

I wouldn't strip away to much from the twi_scanner example. Try the unmodified one. does the sensor actually reply to all those addresses?

RE: BNO080 SH-2 over TWIM

aplatts — Tue, 24 Mar 2020 09:52:45 GMT

Okay, I've worked out the Scanning issue:

I have added in an event capture into the twi instance config:

err_code = nrf_drv_twi_init(&m_twi_instance, &twi_mpu_config, nrf_drv_mpu_twi_event_handler, NULL);

Therefore the scanner will always return success, and I will need to check "NRF_DRV_TWI_EVT_DONE"

I'll continue to build from here!

RE: BNO080 SH-2 over TWIM

aplatts — Mon, 23 Mar 2020 17:44:26 GMT

I've stripped everything back and am using nrf_drv_twi for driving TWI, also removed all code from main.c so it just runs 'nrf_drv_mpu_init' and 'twi_scaner' (see .c below).

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "bno080-nrf-twi.h"
#include "nrf_drv_twi.h"

 #define TWI_ADDRESSES      127

static const nrf_drv_twi_t m_twi_instance = NRF_DRV_TWI_INSTANCE(0);
volatile static bool twi_tx_done = false;
volatile static bool twi_rx_done = false;

uint8_t twi_tx_buffer[MPU_TWI_BUFFER_SIZE];

/**
 * @brief TWI Event Handler.
 * Just the usual way. Nothing special here
 */
static void nrf_drv_mpu_twi_event_handler(nrf_drv_twi_evt_t const * p_event, void * p_context)
{
    switch(p_event->type)
    {
        case NRF_DRV_TWI_EVT_DONE:
            switch(p_event->xfer_desc.type)
            {
                case NRF_DRV_TWI_XFER_TX:
                    twi_tx_done = true;
                    break;
                case NRF_DRV_TWI_XFER_TXTX:
                    twi_tx_done = true;
                    break;
                case NRF_DRV_TWI_XFER_RX:
                    twi_rx_done = true;
                    break;
                case NRF_DRV_TWI_XFER_TXRX:
                    twi_rx_done = true;
                    break;
                default:
                    break;
            }
            break;
        case NRF_DRV_TWI_EVT_ADDRESS_NACK:
            break;
        case NRF_DRV_TWI_EVT_DATA_NACK:
            break;
        default:
            break;
    }
}


/**
 * @brief TWI initialization.
 * Just the usual way. Nothing special here
 */
uint32_t nrf_drv_mpu_init(void)
{
    uint32_t err_code;
    
    const nrf_drv_twi_config_t twi_mpu_config = {
       .scl                = TWI_SCL_PIN,
       .sda                = TWI_SDA_PIN,
       .frequency          = NRF_TWI_FREQ_400K,
       .interrupt_priority = APP_IRQ_PRIORITY_HIGHEST,
       .clear_bus_init     = false
    };
    
    err_code = nrf_drv_twi_init(&m_twi_instance, &twi_mpu_config, nrf_drv_mpu_twi_event_handler, NULL);
    if(err_code != NRF_SUCCESS)
	{
		return err_code;
	}
    
    nrf_drv_twi_enable(&m_twi_instance);

    NRF_LOG_INFO ("nrf_drv_mpu_init");
	
	return NRF_SUCCESS;
}

/**
 * @brief TWI Scanner.
 * Just the usual way. Nothing special here
 */
uint32_t twi_scanner()
{

    uint32_t err_code;
    uint8_t address;
    uint8_t sample_data;
    bool detected_device = false;

    NRF_LOG_INFO("twi_scanner");

    for (address = 1; address <= TWI_ADDRESSES; address++)
    {
        err_code = nrf_drv_twi_rx(&m_twi_instance, address, &sample_data, sizeof(sample_data));
        if (err_code == NRF_SUCCESS)
        {
            detected_device = true;
            NRF_LOG_INFO("TWI device detected at address 0x%x.", address);
        }
        NRF_LOG_FLUSH();
    }

    if (!detected_device)
    {
        NRF_LOG_INFO("No device was found.");
        return NRF_ERROR_INVALID_ADDR;
    }

    return NRF_SUCCESS;

}

I not get the TWI Scanner reporting its found a device at every address...I'm really confused.

RE: BNO080 SH-2 over TWIM

aplatts — Mon, 23 Mar 2020 15:34:36 GMT

Hi Edvin

I think my implementation of nrfx_twim is wrong as I have tried a different TWI device which I have had working before, but I'm not getting the appropriate addresses even from a simple scan.

e.g.

info> app: twi_scanner
<info> app: TWI device detected at address 0x1.
<info> app: TWI device detected at address 0x16.
<info> app: TWI device detected at address 0x2B.
<info> app: TWI device detected at address 0x3C.
<info> app: TWI device detected at address 0x51.
<info> app: TWI device detected at address 0x66.
<info> app: TWI device detected at address 0x77.

There is only one device connected on TWI,

I've double checked my TWI peripheral with older working nrf_twi code and found the device successfully on port 0x4B. I've seen notes that nrfx doesn't play well with Softdevices. I'm using S140 for BLE from SDK 16.0.0

RE: BNO080 SH-2 over TWIM

Edvin — Mon, 23 Mar 2020 15:27:03 GMT

Hello,

I suggest that you try to find a driver for the BMO080. Have you tried to analyze the TWI lines? Is there any data going on the lines? Does it correspond with what you'd expect to see?

BR,

Edvin