NRF52840-DK with MAX30003 ECG Board

[rohit]

Hello,

I am trying to code nRF52840- DK with MAX30003 ECG Board Using SPI. I have referred Arduino Uno Code for MAX30003 ECG.

I need some help for Driver Development if anybody worked on this please share any info.

Thanks and Regards,

Rohit  

[rohit]

Hi,

Thank you for your inputs, Now, I can read INFO (0x0F) register and receive some data in RX buffer but I don't know whether it is receiving correct data or not, can anyone help me how to verify the data.

FYR, attaching code

#define   INFO   ((uint8_t)0x0F)

int main(void)
{
MAX30003_Reg_Read(INFO);
bsp_board_init(BSP_INIT_LEDS);

APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
NRF_LOG_DEFAULT_BACKENDS_INIT();

// nrfx_spim_xfer_desc_t xfer_desc = NRFX_SPIM_XFER_TRX(m_tx_buf, m_length, m_rx_buf, m_length);

nrfx_spim_config_t spi_config = NRFX_SPIM_DEFAULT_CONFIG;
spi_config.frequency = SPIM_FREQUENCY_FREQUENCY_K125;
spi_config.ss_pin = NRFX_SPIM_SS_PIN;
spi_config.miso_pin = NRFX_SPIM_MISO_PIN;
spi_config.mosi_pin = NRFX_SPIM_MOSI_PIN;
spi_config.sck_pin = NRFX_SPIM_SCK_PIN;
spi_config.dcx_pin = NRFX_SPIM_DCX_PIN;
spi_config.use_hw_ss = true;
spi_config.ss_active_high = false;
spi_config.mode = NRF_SPIM_MODE_2; // SCK active low, sample on trailing edge of clock

APP_ERROR_CHECK(nrfx_spim_init(&spi, &spi_config, spim_event_handler, NULL));
nrfx_spim_xfer_desc_t xfer_desc = NRFX_SPIM_XFER_TRX(SPI_TX_Buff, sizeof(SPI_TX_Buff), SPI_RX_Buff, sizeof(SPI_TX_Buff));
NRF_LOG_INFO("NRFX SPIM example started.");

while (1)
{
// Reset rx buffer and transfer done flag
memset(SPI_RX_Buff, 0, m_length);
spi_xfer_done = false;

APP_ERROR_CHECK(nrfx_spim_xfer_dcx(&spi, &xfer_desc, 0, 15));
while (!spi_xfer_done)
{
__WFE();
}

NRF_LOG_FLUSH();

bsp_board_led_invert(BSP_BOARD_LED_0);
nrf_delay_ms(200);
}
}

I want to know, how to analyze that received data is correct or not?

Please check the attached video?

Thanks,

Rohit

[awneil]

You've already forgotten how to properly post source code, then?

rohit said:

I want to know, how to analyze that received data is correct or not?

Really, that has nothing at all to do with Nordic - that's entirely up to you and the specifics of your application.

Again, you need to look to Maxim and the MAX30003 documentation for answers to such questions.

Their product page is here: https://www.maximintegrated.com/en/products/analog/data-converters/analog-front-end-ics/MAX30003.html

Look under 'Design Resources' - they have an evaluation kit , development platform, reference design, Tutorial, Application Note, and other resources ...

Note also their 'Support' link at the left-hand side of the page

[rohit]

Hi HaaKonsh,

I have to plot SPI_RX Buff value on the Keil5 logic analyzer, but I unable to plot this value may  I know 

Is this a supported function?

if it is supported then how to read that value?

I got below errors. please let me know?

Much Thanks!

[haakonsh]

The digital analyzer tool in Keil is not supported. You'll probably need a j-link Pro in order to use it, but I do not really know how to use that Keil feature. 

I do not know what signal you are sampling with the oscilloscope, but you need to sample all four signals at the same time in order verify correct operation of the SPIM peripheral. You will also need to trigger the sampling from the transition of the chip/slave select signal from high to low, instead of a 'free running' sampling scheme like what you are doing.

I believe I've made a mistake in the code I posted:

"The content of the SPI operation consists of a one byte command word (comprised of a seven bit address and a Read/Write mode indicator, i.e., A[6:0] + R/W) followed by a three-byte data word."

SPI_TX_Buff[0] = (Reg_address<<1 ) | RREG;  // 0x1F, 0b00011111

// Should be:

SPI_TX_Buff[0] = Reg_address | (RREG << 7); // 0x8F, 0b10001111

Also, "Note: due to internal initialization procedures, this command will not read-back valid data if it is the first command executed following either a power-cycle event, or a SW_RST event." 


Finnaly I need to say that @awneil has a point. I can help you set up the SPIM drivers and verify that the SPIM peripheral is working as intended, but other than that you really should go to MAXIM for help. They probably have a driver that's easily ported to our platform.