LT9848TR SPI Communication Failing with main ECU (SC123/sc143)

embedded_07 · ‎2024-09-03

Hello;
I hope you are doing well. I have IO board on which LT9848TR is connected which is controlling 8 LEDs , those LEDs are connected in active low configuration. I need to create low at the out pins of LT9848TR to turn on those LEDs. LT9848TR operates with SPI chip select (Active High). I checked my hardware board manually everything is working fine. It really is the issue with accessing the LT9848TR with my main CPU. it should have been straightforward thing. but its just not working. I am attaching my sample code. please check if someone can help me what I am doing wrong here. or if someone already worked with this before share your experience or some sample code of writing/sending a byte to LT9848TR. I will be really thankful to you.
Main CPU:
@https://www.all-electronics.de/wp-content/uploads/migrated/document/170407/1f42b1d0153.pdf

LT9848TR chip:
@https://estore.st.com/en/l9848tr-cpn.html

here is the sample code:

//-----------------------------------------------------------------------------
// SPI
//-----------------------------------------------------------------------------
// Below SPI pins are from SC123(main CPU Board)
#define MISO_PIN 28 // SPI serial in pin - B11
#define MOSI_PIN 27 // SPI serial out pin - A12
#define SCK_PIN 19 // SPI clock pin - B12

//-----------------------------------------------------------------------------
// DIGITAL PINS (Enabling IO)
//-----------------------------------------------------------------------------
#define ENABLE_IO 13
#define CS_U1 31

//-----------------------------------------------------------------------------
// HIGH LOW Macro
//-----------------------------------------------------------------------------
#define PIO_HIGH 4
#define PIO_LOW 5
#define LOW 0
#define HIGH 1

void IO_bearbeiten(void)
{
BYTE Out, x;
int Out_port;

RTX_Sleep_Time(1500);

Out = 0x00;
In_alt = 0x00;

// Hardware einstellen

Log_eintrag(LOG_MESSAGE,LOG_IO,"Init Hardware ...");
if (Daten->Ini.Hardware == IO_3001)
{
pfe_enable_pio(ENABLE_IO, PIO_LOW); // Low
pfe_enable_pio(CS_U1,PIO_HIGH); // High
pfe_enable_pio(CS_U1,PIO_LOW); // Low
spi_init(0, SCK_PIN, MISO_PIN, MOSI_PIN );
pfe_enable_pcs(0); // 0: don't care (PCS0# is no PIO), PCS0# is active when I/O address between 000h..1FFh
In_port = 0x000;
Out_port = 0x000;
}

while(Daten->Tasks_run)
{
// Ausgänge
if (Out != Daten->Io.Out)
{
// von aussen gesetzt
Out = Daten->Io.Out;

if (Daten->Ini.Hardware == IO_3001)
{
// umstellen Bits
Out = 0;
x = ~(Daten->Io.Out);

hal_write_pio(CS_U1,HIGH);
spi_write(&Out,1);
hal_write_pio(CS_U1,LOW);

Out = Daten->Io.Out;
}
else
{
outportb(Out_port,~Out);
}
}
}

---------------------------------------------------------------------
Kindly let me know if there is anything unclear.

Thanks