how to write the parameter of address

[ps_anu]

hi,...... i am merging the nRF52832  and heart rate sensor BH1790,  SEGGER  15.2V i want to read the heart rate sensor , for that i want to write the paramater of address, 41h 42h ... how to write , which function i have to use...... 

[awneil]

ps_anu said:

write the paramater of address, 41h 42h

I don't understand what you mean by that - please clarify

[takurx]

Hi, I just have merged the nRF52832 and heart rate sensor BH1792GLC.

https://github.com/takurx/BH1792GLC-nRF52832-Example

It's better use example of twi-sensor.

You want to set_data_to/get_data_from register(41h, 42h, ...) of slave address.

It can solve nRF SDK's function of nrf_drv_twi_tx/nrf_drv_twi_rx.

One point,

TWI write only use nrf_drv_twi_tx,

But TWI read need to use both nrf_drv_twi_tx and nrf_drv_twi_rx. Thanks.

https://github.com/takurx/BH1792GLC-nRF52832-Example/blob/master/examples/peripheral/twi_sensor/main.c

// Note:  I2C access should be completed within 0.5ms
int32_t i2c_write(uint8_t slv_adr, uint8_t reg_adr, uint8_t *reg, uint8_t reg_size)
{
    ret_code_t err_code;

    /*
    // m_bh1792.prm.msr      = BH1792_PRM_MSR_SINGLE, none
    if (m_bh1792.prm.msr <= BH1792_PRM_MSR_1024HZ) {
      if((slv_adr != BH1792_SLAVE_ADDR) || (reg_adr != BH1792_ADDR_MEAS_SYNC)) {
        while(FlexiTimer2::count == 1999);
      }
    }
    */

    uint32_t timeout = BH1792_TWI_TIMEOUT;

    twi_tx_buffer[0] = reg_adr;
    memcpy(&twi_tx_buffer[1], &reg[0], reg_size);
    
    err_code = nrf_drv_twi_tx(&m_twi, slv_adr, &twi_tx_buffer[0], reg_size + 1, false);
    if(err_code != NRF_SUCCESS) return err_code;
    while((!twi_tx_done) && --timeout) ;
    if(!timeout) return NRF_ERROR_TIMEOUT;
    twi_tx_done = false;

    //return rc;   //rc is return value that arduino, Wire endTransmission, rc:0 is normal
    return 0;
}


// Note:  I2C access should be completed within 0.5ms
int32_t i2c_read(uint8_t slv_adr, uint8_t reg_adr, uint8_t *reg, uint8_t reg_size)
{
    ret_code_t err_code;

    /*
    // m_bh1792.prm.msr      = BH1792_PRM_MSR_SINGLE, none
    if (m_bh1792.prm.msr <= BH1792_PRM_MSR_1024HZ) {
      while(FlexiTimer2::count == 1999);
    }
    */

    uint32_t timeout = BH1792_TWI_TIMEOUT;

    err_code = nrf_drv_twi_tx(&m_twi, slv_adr, &reg_adr, 1, false);
    if(err_code != NRF_SUCCESS) return err_code;

    while((!twi_tx_done) && --timeout);
    if(!timeout) return NRF_ERROR_TIMEOUT;
    twi_tx_done = false;

    err_code = nrf_drv_twi_rx(&m_twi, slv_adr, reg, reg_size);
    if(err_code != NRF_SUCCESS) return err_code;

    timeout = BH1792_TWI_TIMEOUT;
    while((!twi_rx_done) && --timeout);
    if(!timeout) return NRF_ERROR_TIMEOUT;
    twi_rx_done = false;

    //return rc;  //rc:0 is normal, rc:4 is error. but in nrf5 when case of error, already return
    return 0;
}

I also will try BH1790GLC. It have to exist heart rate(BPM, Upper one is only measured raw data) example.

BH1790GLC_HeartRate.zip - http://micro.rohm.com/en/download_support/sensor_module/kiyaku.php?file=data/software/BH1790GLC_HeartRate.zip