Other Parts Discussed in Thread: EK-TM4C129EXL
Tool/software: TI-RTOS
Hi Ralph,
I am trying to interface EK-TM4C129EXL with the 8*8 LED module to display some characters. When I try to send 0x00 (Value - 0) through SPI the LED's in the display module should not glow, but it glows. I am not able to find why tose led glows.. Here is the code
/* XDCtools Header files */
#include <xdc/std.h>
#include <xdc/runtime/System.h>
#include <xdc/runtime/Error.h>
/* BIOS Header files */
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Semaphore.h>
/* TI-RTOS Header files */
#include <ti/drivers/GPIO.h>
#include <xdc/runtime/System.h>
//#include <xdc/cfg/global.h>
/* BIOS Header files */
#include <ti/sysbios/knl/Task.h>
/* TI-RTOS Header files */
#include <ti/drivers/GPIO.h>
#include <ti/drivers/SPI.h>
#include <ti/sysbios/BIOS.h>
#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#define TASKSTACKSIZE 1024
Task_Struct task0Struct;
Char task0Stack[TASKSTACKSIZE];
void spiDataSend();
void multiplexing();
volatile int rowSelect = 0;
volatile int count = 0;
extern Semaphore_Handle sem1;
extern Semaphore_Handle sem2;
UChar transmitBuffer[1] = {0x00};
/* Board Header file */
#include "Board.h"
void timerFunc()
{
//static int count = 0;
if (count++ & 1) {
Semaphore_post(sem2);
}
else {
Semaphore_post(sem1);
}
}
/*Task1 is in a loop pending on sem1*/
tsk1Func(UArg arg0, UArg arg1)
{
//GPIO_toggle(Board_LED1);
while (1) {
Semaphore_pend(sem1, BIOS_WAIT_FOREVER);
multiplexing();
/* task1 work here */
}
}
/*Task2 is in a loop pending on sem2*/
tsk2Func(UArg arg0, UArg arg1)
{
//GPIO_toggle(Board_LED0);
while (1) {
Semaphore_pend(sem2, BIOS_WAIT_FOREVER);
spiDataSend();
/* task2 work here */
}
}
void spiDataSend()
{
SPI_Handle spi;
SPI_Params spiParams;
SPI_Params_init(&spiParams);
spiParams.dataSize = 1; /* dataSize can range from 4 to 8 bits */
spiParams.transferMode = SPI_MODE_BLOCKING;
spiParams.mode = SPI_MASTER;
spiParams.bitRate = 2000000;
spiParams.transferCallbackFxn = NULL;
spi = SPI_open(Board_SPI0, &spiParams);
if (spi == NULL) {
/* Error opening SPI */
}
SPI_Transaction spiTransaction;
spiTransaction.count = 8;
spiTransaction.txBuf = transmitBuffer;
spiTransaction.rxBuf = NULL;
SPI_transfer(spi, &spiTransaction);
SPI_close(spi);
}
void multiplexing()
{
GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_0 , 1); // LED Driver part of code this part works fine...
GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_2 , 1);
GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_0 , 0);
GPIOPinWrite(GPIO_PORTE_BASE, (GPIO_PIN_0|GPIO_PIN_1) , rowSelect);
GPIOPinWrite(GPIO_PORTD_BASE, GPIO_PIN_2 , 0);
rowSelect++;
if (rowSelect > 3)
{
rowSelect = 0;
}
}
/*
* ======== main ========
*/
int main(void)
{
/* Call board init functions */
Board_initGeneral();
Board_initGPIO();
Board_initSPI();
GPIOPinTypeGPIOOutput(GPIO_PORTE_BASE, (GPIO_PIN_0|GPIO_PIN_1)); // Initializing the Decoder part
GPIOPinTypeGPIOOutput(GPIO_PORTD_BASE,(GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3)); // Initializing the SPI Driver part
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOE))
{
}
Task_Params taskParams;
Task_Params_init(&taskParams);
taskParams.priority = 2;
taskParams.stackSize = TASKSTACKSIZE;
taskParams.stack = &task0Stack;
Task_construct(&task0Struct, (Task_FuncPtr)spiDataSend, &taskParams, NULL);
/* Start BIOS */
BIOS_start();
return (0);
}
You can notice that the value in the tranmitbuffer is 0x00 Still the LED glows....
I am having certain doubts,
spi = SPI_open(Board_SPI0, &spiParams);
----> Do Board_SPI0 open the SPI on PORTD ??? ----> In which register the value in the transmit buffer will be writeen ??? ----> I can't able to see data value in SSI_DR_DATA - SSI Receive/Transmit Data
