Clock Matching from tm4c129 to tm4c123

Hello Ankeet

Ankeet Gugale said:

I am using sysctlclock freqset((sysctl_xtal_25Mhz | sysctl_osc_main| sysctl_use pll | sysctl_cfg_vco480), 40000000);on TM4C129 this is giving me clk frq of 40Mhz.

SysCtlClockSet(SYSCTL_SYSDIV_5| SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |SYSCTL_XTAL_16MHZ); on TM4C123 this gives me frq of 40Mhz when i do syscltclockget();

If you are getting 40MHz with the TM4C123 on calling the function SysCtlClockGet, then what is the issue?

Hello Amit,

Following is the code in which i have interfaced dht 11 sensor with tm4c129 and tm4c123.
when i interface dht with tm4c129 i am getting the values , but when i am interfacing it with tm4c123 it is not working.
i have changed the clock API as mentioned in my last post.
what might be the reason? will u pls help me out?

/*
* main.c
*/
#include <stdint.h>
//#include <stdio.h>
#include <stdbool.h>
//#include <string.h>
#include <stdlib.h>
#include "inc/hw_memmap.h"
#include "inc/hw_ints.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/interrupt.h"
//#include "driverlib/uart.h"
#include "driverlib/debug.h"
#include "inc/hw_gpio.h"
#include "inc/hw_types.h"
#include "inc/hw_sysctl.h"
#include "driverlib/timer.h"
#include "utils/ustdlib.h"

int temp;
int humidity;
int32_t TemperatureHumidity[2],count=0;

void ConfigureUART(void)
{
SysCtlPeripheralEnable(SYSCTL_PERIPH_UART5);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);

//UART RX and TX Configure UART
GPIOPinConfigure(GPIO_PE4_U5RX);
GPIOPinConfigure(GPIO_PE5_U5TX);
//GPIO C6 and C7 as UART function ,they must be configured for use as peripheral
GPIOPinTypeUART(GPIO_PORTE_BASE, GPIO_PIN_4 | GPIO_PIN_5);
//UARTConfigSetExpClk(UART5_BASE, SysCtlClockGet(),115200,(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |UART_CONFIG_PAR_NONE));
UARTEnable(UART5_BASE);
}
int ReadDHT()
{
// bit buffers & timeout
char bitcount;
char byte;
char bits[5] = {0,0,0,0,0};
unsigned int bitints[6];
long timerval;


unsigned int loopCnt = 10000;

#define MY_PIN_PERIPH SYSCTL_PERIPH_GPIOA
#define MY_PIN_PORTBASE GPIO_PORTA_BASE
#define MY_PINNR GPIO_PIN_5

#define MY_TIMER_PERIPH SYSCTL_PERIPH_TIMER0
#define MY_TIMERBASE TIMER0_BASE
#define MY_TIMER TIMER_B

SysCtlPeripheralEnable(MY_TIMER_PERIPH);
TimerConfigure(MY_TIMERBASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_B_ONE_SHOT);


SysCtlPeripheralEnable(MY_PIN_PERIPH);

GPIOPinTypeGPIOOutput(MY_PIN_PORTBASE, MY_PINNR);


GPIOPinWrite(MY_PIN_PORTBASE, MY_PINNR, 0x0);

// #loops = loops_per_us*time_in_us = time in us * loops/us = time_in_us *(clockfreq/10000000)
SysCtlDelay((SysCtlClockGet()/3)/30 ); // -> 30 ms

GPIOPinTypeGPIOInput(MY_PIN_PORTBASE, MY_PINNR);


loopCnt = SysCtlClockGet()/100;
while(GPIOPinRead(MY_PIN_PORTBASE, MY_PINNR))
{
loopCnt = loopCnt -1;
if (loopCnt == 0)
return 0;
}


loopCnt = SysCtlClockGet()/100;
while(!(GPIOPinRead(MY_PIN_PORTBASE, MY_PINNR))) //0
{
loopCnt = loopCnt -1;
if (loopCnt == 0)
return 0;
}

loopCnt = SysCtlClockGet()/100;
while(GPIOPinRead(MY_PIN_PORTBASE, MY_PINNR))
{
loopCnt = loopCnt -1;
if (loopCnt == 0)
return 0;
}

// start receiving 40 bits
char i;
bitcount = 7;
byte = 0;

int conta = 0;
int timerval2=0;

int largest = 0;
int lowest = 99999;

for (i=0; i < 40; i++)
{
loopCnt = SysCtlClockGet()/100;
while(!(GPIOPinRead(MY_PIN_PORTBASE, MY_PINNR)))
{
loopCnt = loopCnt -1;
if (loopCnt == 0)
return 0;
}


TimerDisable(MY_TIMERBASE, MY_TIMER);
TimerConfigure(MY_TIMERBASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_B_ONE_SHOT);
TimerLoadSet(MY_TIMERBASE, MY_TIMER, SysCtlClockGet()/4000);
TimerEnable(MY_TIMERBASE, MY_TIMER);
timerval = TimerValueGet(MY_TIMERBASE, MY_TIMER);

loopCnt = SysCtlClockGet()/100;
while(GPIOPinRead(MY_PIN_PORTBASE, MY_PINNR))
{
loopCnt = loopCnt -1;
if (loopCnt == 0)
return 0;
}

timerval2 = TimerValueGet(MY_TIMERBASE, MY_TIMER);


conta = timerval - timerval2;

if (conta>largest)
largest = conta;

if (conta<lowest)
lowest = conta;

if ((conta) > (1000))
bits[byte] |= (1 << bitcount);
if (bitcount == 0)
{
bitcount = 7;
byte++;
}else{
bitcount--;
}
}

bitints[0] = ((unsigned int) bits[0] & (0x000000FF));
bitints[1] = ((unsigned int) bits[1] & (0x000000FF));
bitints[2] = ((unsigned int) bits[2] & (0x000000FF));
bitints[3] = ((unsigned int) bits[3] & (0x000000FF));
bitints[4] = ((unsigned int) bits[4] & (0x000000FF));

if(((bitints[0] + bitints[1] + bitints[2] + bitints[3]) & (0x000000FF)) == bitints[4]){
temp = bitints[2];
humidity = bitints[0];
return 1;
}else{
return 0;
}

}

void main(void) {
SysCtlClockSet(SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |SYSCTL_XTAL_16MHZ);

ConfigureUART();

//UARTprintf("Its runing at : %d\n",SysCtlClockGet());
while(1){
SysCtlDelay(SysCtlClockGet()/ 3);

if(ReadDHT() == 0)
{
temp=0;
humidity=0;
UARTCharPut(UART5_BASE,'E');
}
else
{
// UARTprintf("Temp %d !\n",temp);
// UARTprintf("Hum %d !\n",humidity);
TemperatureHumidity[0]=temp;
TemperatureHumidity[1]=humidity;
UARTCharPut(UART5_BASE,TemperatureHumidity[count]);
count++;
}
}

}


Thank You in advance.

Hello Ankeet

The UART configuration line in your code is commented!!!

//UARTConfigSetExpClk(UART5_BASE, SysCtlClockGet(),115200,(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |UART_CONFIG_PAR_NONE));