I'm hoping someone can take a look at my code and help me figure out why it's not working. I am trying to sample an analog audio signal through the on-board ADC. I can get a reading when I configure the ADC sequence with ADC_Trigger_Processor, but have been unable to get my code to work when I add a periodic timer and try to configure it using ADC_Trigger_Timer. As far as I can tell the interrupt just never happens. I am using the TivaWare Peripheral Driver Library functions. My lab instructor looked at my code and told me that everything looks correct, and he couldn't figure out why it's not working either. Here's my main code:
#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/sysctl.h"
#include "driverlib/adc.h"
#include "driverlib/interrupt.h"
#include "inc/tm4c123gh6pm.h"
#include "driverlib/gpio.h"
#include "driverlib/timer.h"
uint32_t ui32Sample;
// GPIO initialization
void GPIO_Init(void){
//
// Enable Peripheral Clocks
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
//
// Enable pin PE3 for ADC AIN0
//
GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_3);
}
//ADC0 initializaiton
void ADC0_Init(void)
{
SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ); // configure the system clock to be 40MHz
SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0); //activate the clock of ADC0
SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0); //activate the clock of Timer0
SysCtlDelay(2); //insert a few cycles after enabling the peripheral to allow the clock to be fully activated.
TimerConfigure(TIMER0_BASE, TIMER_CFG_PERIODIC); // configure Timer0 as periodic
TimerLoadSet(TIMER0_BASE, TIMER_A, 10000); //load Timer0A with period of 10000 clock cycles
//IntPrioritySet(INT_TIMER0A, 0x00); // configure Timer0A interrupt priority as 0
ADCSequenceDisable(ADC0_BASE, 3); //disable ADC0 before the configuration is complete
ADCSequenceConfigure(ADC0_BASE, 3, ADC_TRIGGER_TIMER, 0); // will use ADC0, SS3, processor-trigger, priority 0
//ADC0 SS3 Step 0, sample from ADC SS3 channel 0, completion of this step will set RIS, last sample of the sequence
ADCSequenceStepConfigure(ADC0_BASE,3,0,ADC_CTL_CH0|ADC_CTL_IE|ADC_CTL_END);
IntPrioritySet(INT_ADC0SS3, 0x00); // configure ADC0 SS3 interrupt priority as 0
IntEnable(INT_ADC0SS3); // enable interrupt on ADC0 SS3
ADCIntEnableEx(ADC0_BASE, ADC_INT_SS3); // arm interrupt of ADC0 SS3
TimerControlTrigger(TIMER0_BASE, TIMER_A, true); // specifies trigger timer
ADCSequenceEnable(ADC0_BASE, 3); //enable ADC0
}
//interrupt handler
void ADC0_Handler(void)
{
ADCIntClear(ADC0_BASE, 3); // clear the interrupt
ADCSequenceDataGet(ADC0_BASE, 3, &ui32Sample); // collect sample data from PE3
}
int main(void)
{
ADC0_Init(); // initialize ADC0 and Timer0
GPIO_Init(); // initialize gpio
IntMasterEnable(); // globally enable interrupt
while(1)
{
}
}
and here's the part of my startup_rvmdk.s file that I've edited:
;******************************************************************************
;
; External declarations for the interrupt handlers used by the application.
;
;******************************************************************************
EXTERN ADC0_Handler
;******************************************************************************
;
; The vector table.
;
;******************************************************************************
EXPORT __Vectors
__Vectors
DCD StackMem + Stack ; Top of Stack
DCD Reset_Handler ; Reset Handler
DCD NmiSR ; NMI Handler
DCD FaultISR ; Hard Fault Handler
DCD IntDefaultHandler ; The MPU fault handler
DCD IntDefaultHandler ; The bus fault handler
DCD IntDefaultHandler ; The usage fault handler
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD IntDefaultHandler ; SVCall handler
DCD IntDefaultHandler ; Debug monitor handler
DCD 0 ; Reserved
DCD IntDefaultHandler ; The PendSV handler
DCD IntDefaultHandler ; The SysTick handler
DCD IntDefaultHandler ; GPIO Port A
DCD IntDefaultHandler ; GPIO Port B
DCD IntDefaultHandler ; GPIO Port C
DCD IntDefaultHandler ; GPIO Port D
DCD IntDefaultHandler ; GPIO Port E
DCD IntDefaultHandler ; UART0 Rx and Tx
DCD IntDefaultHandler ; UART1 Rx and Tx
DCD IntDefaultHandler ; SSI0 Rx and Tx
DCD IntDefaultHandler ; I2C0 Master and Slave
DCD IntDefaultHandler ; PWM Fault
DCD IntDefaultHandler ; PWM Generator 0
DCD IntDefaultHandler ; PWM Generator 1
DCD IntDefaultHandler ; PWM Generator 2
DCD IntDefaultHandler ; Quadrature Encoder 0
DCD IntDefaultHandler ; ADC Sequence 0
DCD IntDefaultHandler ; ADC Sequence 1
DCD IntDefaultHandler ; ADC Sequence 2
DCD ADC0_Handler ; ADC Sequence 3
DCD IntDefaultHandler ; Watchdog timer
DCD IntDefaultHandler ; Timer 0 subtimer A
DCD IntDefaultHandler ; Timer 0 subtimer B
DCD IntDefaultHandler ; Timer 1 subtimer A
DCD IntDefaultHandler ; Timer 1 subtimer B
DCD IntDefaultHandler ; Timer 2 subtimer A
DCD IntDefaultHandler ; Timer 2 subtimer B
DCD IntDefaultHandler ; Analog Comparator 0
DCD IntDefaultHandler ; Analog Comparator 1
DCD IntDefaultHandler ; Analog Comparator 2
DCD IntDefaultHandler ; System Control (PLL, OSC, BO)
DCD IntDefaultHandler ; FLASH Control
DCD IntDefaultHandler ; GPIO Port F
DCD IntDefaultHandler ; GPIO Port G
DCD IntDefaultHandler ; GPIO Port H
DCD IntDefaultHandler ; UART2 Rx and Tx
DCD IntDefaultHandler ; SSI1 Rx and Tx
DCD IntDefaultHandler ; Timer 3 subtimer A
DCD IntDefaultHandler ; Timer 3 subtimer B
DCD IntDefaultHandler ; I2C1 Master and Slave
DCD IntDefaultHandler ; Quadrature Encoder 1
DCD IntDefaultHandler ; CAN0
DCD IntDefaultHandler ; CAN1
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD IntDefaultHandler ; Hibernate
DCD IntDefaultHandler ; USB0
DCD IntDefaultHandler ; PWM Generator 3
DCD IntDefaultHandler ; uDMA Software Transfer
DCD IntDefaultHandler ; uDMA Error
DCD IntDefaultHandler ; ADC1 Sequence 0
DCD IntDefaultHandler ; ADC1 Sequence 1
DCD IntDefaultHandler ; ADC1 Sequence 2
DCD IntDefaultHandler ; ADC1 Sequence 3
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD IntDefaultHandler ; GPIO Port J
DCD IntDefaultHandler ; GPIO Port K
DCD IntDefaultHandler ; GPIO Port L
DCD IntDefaultHandler ; SSI2 Rx and Tx
DCD IntDefaultHandler ; SSI3 Rx and Tx
DCD IntDefaultHandler ; UART3 Rx and Tx
DCD IntDefaultHandler ; UART4 Rx and Tx
DCD IntDefaultHandler ; UART5 Rx and Tx
DCD IntDefaultHandler ; UART6 Rx and Tx
DCD IntDefaultHandler ; UART7 Rx and Tx
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD IntDefaultHandler ; I2C2 Master and Slave
DCD IntDefaultHandler ; I2C3 Master and Slave
DCD IntDefaultHandler ; Timer 4 subtimer A
DCD IntDefaultHandler ; Timer 4 subtimer B
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD IntDefaultHandler ; Timer 5 subtimer A
DCD IntDefaultHandler ; Timer 5 subtimer B
DCD IntDefaultHandler ; Wide Timer 0 subtimer A
DCD IntDefaultHandler ; Wide Timer 0 subtimer B
DCD IntDefaultHandler ; Wide Timer 1 subtimer A
DCD IntDefaultHandler ; Wide Timer 1 subtimer B
DCD IntDefaultHandler ; Wide Timer 2 subtimer A
DCD IntDefaultHandler ; Wide Timer 2 subtimer B
DCD IntDefaultHandler ; Wide Timer 3 subtimer A
DCD IntDefaultHandler ; Wide Timer 3 subtimer B
DCD IntDefaultHandler ; Wide Timer 4 subtimer A
DCD IntDefaultHandler ; Wide Timer 4 subtimer B
DCD IntDefaultHandler ; Wide Timer 5 subtimer A
DCD IntDefaultHandler ; Wide Timer 5 subtimer B
DCD IntDefaultHandler ; FPU
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD IntDefaultHandler ; I2C4 Master and Slave
DCD IntDefaultHandler ; I2C5 Master and Slave
DCD IntDefaultHandler ; GPIO Port M
DCD IntDefaultHandler ; GPIO Port N
DCD IntDefaultHandler ; Quadrature Encoder 2
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD IntDefaultHandler ; GPIO Port P (Summary or P0)
DCD IntDefaultHandler ; GPIO Port P1
DCD IntDefaultHandler ; GPIO Port P2
DCD IntDefaultHandler ; GPIO Port P3
DCD IntDefaultHandler ; GPIO Port P4
DCD IntDefaultHandler ; GPIO Port P5
DCD IntDefaultHandler ; GPIO Port P6
DCD IntDefaultHandler ; GPIO Port P7
DCD IntDefaultHandler ; GPIO Port Q (Summary or Q0)
DCD IntDefaultHandler ; GPIO Port Q1
DCD IntDefaultHandler ; GPIO Port Q2
DCD IntDefaultHandler ; GPIO Port Q3
DCD IntDefaultHandler ; GPIO Port Q4
DCD IntDefaultHandler ; GPIO Port Q5
DCD IntDefaultHandler ; GPIO Port Q6
DCD IntDefaultHandler ; GPIO Port Q7
DCD IntDefaultHandler ; GPIO Port R
DCD IntDefaultHandler ; GPIO Port S
DCD IntDefaultHandler ; PWM 1 Generator 0
DCD IntDefaultHandler ; PWM 1 Generator 1
DCD IntDefaultHandler ; PWM 1 Generator 2
DCD IntDefaultHandler ; PWM 1 Generator 3
DCD IntDefaultHandler ; PWM 1 Fault
;******************************************************************************
I don't know if it's important or not, but I'm using Kiel's uVision IDE and Stellaris IDCI debugger. Hopefully someone can take a look this and tell me if I'm missing something.
