Hi Amit,
here i have a problem with ssi module. I'm using tm4c123 launchpad. In my program i'm transmitting command to the external mcp41010..... but by seeing my output from mcp, it is reveal that my data was not transmitted properly..... I dont know that where i did mistake.....
its my program:
#include<stdint.h>
#include<stdbool.h>
#include<hw_memmap.h>
#include<hw_types.h>
#include<sysctl.h>
#include<gpio.h>
#include<ssi.h>
#define CS GPIO_PIN_1 //GPIO PIN for Slave Select
void dly(unsigned int ms)
{
ms=(SysCtlClockGet()/3.0)*ms/1000;
SysCtlDelay(ms);
}
void ssi_init(){
SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI0); //SSI ENABLE
SysCtlPeripheralReset(SYSCTL_PERIPH_SSI0); //Reset ssi mode
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA); //ENABLE GPIOA
GPIOPinTypeGPIOOutput(GPIO_PORTA_BASE, GPIO_PIN_2|GPIO_PIN_5); //SCK, SO
GPIOPinTypeGPIOInput(GPIO_PORTA_BASE, GPIO_PIN_4); //SI
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE); //ENABLE GPIOE
GPIOPinTypeGPIOOutput(GPIO_PORTE_BASE, GPIO_PIN_1);// PE1 as output
GPIOPinConfigure(GPIO_PA2_SSI0CLK); //sck
//GPIOPinConfigure(GPIO_PA4_SSI0RX); //SI it is not necessary. bcoz mcp wont transmit anything
GPIOPinConfigure(GPIO_PA5_SSI0TX); //SO
GPIOPinTypeSSI(GPIO_PORTA_BASE, GPIO_PIN_2|GPIO_PIN_4|GPIO_PIN_5);
SSIClockSourceSet(SSI0_BASE, SSI_CLOCK_SYSTEM); // sets the system clock as the source of clock
SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_0, SSI_MODE_MASTER, 20000000, 8);// defines base, System clk, Mode 0 = SPH = SPO = 0,Master, 125 KHz, no. of bits = 8 = 1 byte transfer
SSIEnable(SSI0_BASE); //enables SSI
}
void mcp(unsigned char dat)
{
GPIOPinWrite(GPIO_PORTE_BASE, CS, ~CS); //CS = 0;
dly(500);
//value transmitted from Controller
SSIDataPut(SSI0_BASE,0x11);while(SSIBusy(SSI0_BASE)); dly(100); //mcp write
SSIDataPut(SSI0_BASE, dat);while(SSIBusy(SSI0_BASE)); dly(100); //value to be written
GPIOPinWrite(GPIO_PORTE_BASE, CS, CS); //CS = 1;
}
void main()
{
SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ);
ssi_init();dly(200);
while(1)
{
mcp(0);
}
}
always i'm reading 2.5v from mcp...........
