Hi ,
Need a bit of help here.
I am trying to use TWI and SPI in a single code for communicating with two different slave devices, the LTC2941 coulomb counter and the EM4325 RFID tag. I have written a switch case program similar to the one given in SDK 12.3.0 , and added an SPI case for the same. Here is a snippet of my main function (it is similar to the twis_master_with_twis_slave code provided in the SDK) :
int main(void)
{
ret_code_t err_code;
/* Initialization of UART */
bsp_board_leds_init();
APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
/* Initializing simulated EEPROM */
err_code = eeprom_simulator_init();
APP_ERROR_CHECK(err_code);
/* Initializing TWI master interface for EEPROM */
err_code = twi_master_init();
APP_ERROR_CHECK(err_code);
while (1)
{
nrf_delay_us(9000) ;
// Welcome message
NRF_LOG_RAW_INFO(
"\n \n This battery state of charge example \r\n"
"You can access coulumb counter and rfid using following commands:\r\n"
);
help_print();
NRF_LOG_FLUSH();
uint8_t c = NRF_LOG_GETCHAR();
switch ((char)c)
{
case '\n':
case '\r':
break;
case 'p': // print eeprom data
do_print_data();
break;
case 'w': // configure or write into ltc2941
//do_string_write();
write_into_kunal_ltc2941();
break;
case 'c': // clear the eeprom data
do_clear_eeprom();
break;
case 'q': // get the state of charge
SOC();
break ;
case 's': // swap the battery and store data in the rfid tag
rfid_spi() ;
break ;
case 'x':
{
uint32_t error = eeprom_simulator_error_get_and_clear();
NRF_LOG_WARNING("Error word: %x\r\n", (unsigned int)error);
}
break;
default:
NRF_LOG_RAW_INFO("You selected %c\r\n", (char)c);
NRF_LOG_RAW_INFO("Unknown command, try one of the following:\r\n");
help_print();
break;
}
if (eeprom_simulator_error_check())
{
NRF_LOG_RAW_INFO(
"WARNING: EEPROM transmission error detected.\r\n"
"Use 'x' command to read error word.\r\n"
);
}
NRF_LOG_FLUSH();
}
}
EM4325 datasheet : http://www.emmicroelectronic.com/products/rf-identification-security/epc-and-uhf-ics/em4325
LTC 2941 datasheet : http://cds.linear.com/docs/en/datasheet/2941fb.pdf
Here is the rfid_spi() function which is being called inside the switch case statement for communicating with EM4325 :
static void rfid_spi(void) { uint32_t spike_clk = 24 ; uint32_t spike_miso = 23; uint32_t spike_mosi = 22 ; nrf_spim_enable( (NRF_SPIM_Type *)SPI_INSTANCE); //nrf_spim_event_clear((NRF_SPIM_Type *)SPI_INSTANCE , NRF_SPI_EVENT_READY ) ; nrf_spim_configure((NRF_SPIM_Type *) SPI_INSTANCE , NRF_SPIM_MODE_0 , NRF_SPIM_BIT_ORDER_MSB_FIRST) ; nrf_spim_pins_set( (NRF_SPIM_Type *)SPI_INSTANCE , spike_clk ,spike_mosi, spike_miso ) ; nrf_spim_frequency_set((NRF_SPIM_Type *)SPI_INSTANCE, NRF_SPIM_FREQ_250K); // nrf_spim_int_enable ((NRF_SPIM_Type *)SPI_INSTANCE,SPI_INTENSET_READY_Set) ; //memset(m_rx_buf, 0, 20); //m_length spi_xfer_done = false; const uint8_t p1 = 0xff; const uint8_t p2 = 0x65; m_tx_buf[0] = 0xE8; /**< TX buffer. */ m_tx_buf[1] = 0x2c; m_tx_buf[2] = 0xee ; m_tx_buf[3] = 0xab; nrf_gpio_cfg_output(25) ; // slave select pin nrf_gpio_pin_clear(25) ; // set ss pin to low to activate SPI nrf_spim_task_trigger((NRF_SPIM_Type *)SPI_INSTANCE, NRF_SPIM_TASK_START ) ; // start spi bool gg = nrf_spim_event_check ( (NRF_SPIM_Type *) SPI_INSTANCE, NRF_SPIM_EVENT_STARTED ) ; NRF_LOG_RAW_INFO("\n has spi started? %x \n",gg) ; for (int i=0 ; i<sizeof(m_tx_buf) ; i++){ nrf_spim_tx_buffer_set((NRF_SPIM_Type *)SPI_INSTANCE , &(m_tx_buf[i]), 5 ) ; bool gg = nrf_spim_event_check((NRF_SPIM_Type *) SPI_INSTANCE, NRF_SPIM_EVENT_STARTED ) ; NRF_LOG_RAW_INFO("event is %x % \r\n", gg); } nrf_delay_us(8000) ; //delay required for EM4325 write operation. for (int i=0 ; i<sizeof(m_rx_buf) ; i++){ nrf_spim_rx_buffer_set((NRF_SPIM_Type *)SPI_INSTANCE,&m_rx_buf[i],20) ; NRF_LOG_RAW_INFO("\n receive buffer byte %d = %x % \r\n", i, m_rx_buf[i]); } nrf_gpio_pin_set(25) ; nrf_spim_disable( (NRF_SPIM_Type *) SPI_INSTANCE); }I am using the SPIM HAL to communicate with EM4325, this is because when I tried to integrate the spi and twi master codes (of SDK 12.3) , it was giving me garbage values in the receive buffer of the SPI, hence I tried to use the HAL. When I used the SPIM HAL, .( I have referred to the following webpage for using the HAL, my SPI Instance is 2 and TWI instance is 0 ----- https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk52.v0.9.2%2Fgroup__nrf__spim__hal.html )
I tried to use the event check function but it was returning me zero values , which indicated that the SPI was not being initiated by the HAL functions
What is the reason for this?? I have attached the serial window output below:
Can someone please help me with a switch case code in which I can use SPI for one switch case and I2C for another ? Is it possible to do this using HAL or with the API which have been provided in SDK 12.3 itself?
Also, when do I know if I should use EASY DMA or not?
Thanking you in advance,
Kunal.
