//*****************************************************************************
//
// Blink the on-board LED.
//
//*****************************************************************************
int
main(void)
{
volatile uint32_t ui32Loop;
//
// Enable the GPIO port that is used for the on-board LED.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOG);
//
// Check if the peripheral access is enabled.
//
while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOG))
{
}
//
// Enable the GPIO pin for the LED (PG2). Set the direction as output, and
// enable the GPIO pin for digital function.
//
GPIOPinTypeGPIOOutput(GPIO_PORTG_BASE, GPIO_PIN_2);
//
// Loop forever.
//
while(1)
{
//
// Turn on the LED.
//
led_turn_on();
//
// Delay for a bit.
//
for(ui32Loop = 0; ui32Loop < 200000; ui32Loop++)
{
}
//
// Turn off the LED.
//
led_turn_off();
//
// Delay for a bit.
//
for(ui32Loop = 0; ui32Loop < 200000; ui32Loop++)
{
}
}
}
int main(void) {
cli();
/* We need to use a timer to control how long our main loop iterations are.
* Experiments showed that the main loop was executing approximately every
* 3.2 milliseconds, which is too quick for the sdcard to write a block
* of data. Here we are configuring Timer1 because it is a "16-bit" timer
* which would allow us to count to values greater than (2^8)-1. For a pre-
* scale value of 64, the timer will count up to 16,000,000/64 = 250,000.
* This gives us a timer period of 250,000 ticks/sec = 4 microseconds/tick.
* Suppose we want the main loop to run 40 times per second (40 Hz), we would
* need to restart the loop when Timer1 reaches the value: 250,000/40 = 6250
* See Atmel datasheet for Mega, Section 17.11
*/
TCCR1A = 0b00000000; // Normal operation; no waveform generation by default
TCCR1B = 0b00000011; // No input capture, waveform gen; prescaler = 64
TCCR1C = 0b00000000; // No output compare
TIMSK1 = 0b00000000;
// TIMING DEBUG - Digital Pin 4
DDRG |= (1 << 5);
char msg[64];
if (button_init() &&
uwrite_init() &&
cmps10_init() &&
sdcard_init()) {
uwrite_print_buff("All systems go!\r\n");
return 0;
} else {
uwrite_print_buff("There was an error during init\r\n");
return 1;
}
memset(msg, 0, sizeof(msg));
memset(&statevars, 0, sizeof(statevars));
statevars.prefix = 0xDADAFEED;
statevars.suffix = 0xCAFEBABE;
uint32_t iterations = 0;
sei();
TIMSK1 = 0b00000001;
while (1) {
// TIMING DEBUG FOR OSCILLOSCOPE
PORTG |= (1 << 5);
TCNT1 = 0;
button_update();
cmps10_update_all();
statevars.main_loop_counter = iterations;
mainloop_timer_overflow = 0;
// TIMING DEBUG FOR OSCILLOSCOPE
PORTG &= (0 << 5);
if (button_is_pressed()) {
uwrite_print_buff("The button is pressed! The LED should be on.\r\n");
led_turn_on();
statevars.mission_started = 1;
} else {
led_turn_off();
statevars.mission_started = 0;
}
snprintf(msg, sizeof(msg),
"Heading: %u Pitch: %d Roll: %hhd\r\n",
cmps10_heading, cmps10_pitch, cmps10_roll);
// Needed to cast these values to display negative pitch and roll values
//(int8_t) statevars.heading_raw, (int8_t) statevars.pitch_deg, (int8_t) statevars.roll_deg);
uwrite_print_buff(msg);
sdcard_write_data();
iterations++;
if (iterations > 256) {
uwrite_print_buff("Finished collecting data!\r\n");
break;
}
/* Ensure that the main loop period is as long as we want it to be.
* This means (1) triggering the main loop to restart we notice it is
* running too long, and (2) performing busy waiting if the instructions
* above finish before the desired loop duration.
*/
while (1) {
if (mainloop_timer_overflow) {
break;
}
if (TCNT1 >= MAINLOOP_PERIOD_TICKS) {
break;
}
}
}
return 0;
}