/*
* Data i/o: send byte to device.
* Return received byte.
*/
unsigned dev_sdcard_io (cpu_mips_t *cpu, unsigned data)
{
pic32_t *pic32 = (pic32_t*) cpu->vm->hw_data;
sdcard_t *d = pic32->sdcard[0].select ? &pic32->sdcard[0] :
pic32->sdcard[1].select ? &pic32->sdcard[1] : 0;
unsigned reply;
if (! d || ! d->fd) {
TRACE ("sdcard: unselected i/o\n");
return 0xFF;
}
data = (unsigned char) data;
reply = 0xFF;
if (d->count == 0) {
d->buf[0] = data;
if (data != 0xFF)
d->count++;
} else {
switch (d->buf[0]) {
case CMD_GO_IDLE: /* CMD0: reset */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7)
reply = 0x01;
break;
case CMD_APP: /* CMD55: application prefix */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7) {
reply = 0;
d->count = 0;
}
break;
case CMD_SEND_OP_SDC: /* ACMD41: initialization */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7)
reply = 0;
break;
case CMD_SET_BLEN: /* Set block length */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7) {
d->blen = d->buf[1] << 24 | d->buf[2] << 16 |
d->buf[3] << 8 | d->buf[4];
TRACE ("sdcard%d: set block length %u bytes\n", d->unit, d->blen);
reply = (d->blen > 0 && d->blen <= 1024) ? 0 : 4;
}
break;
case CMD_SET_WBECNT: /* Set write block erase count */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7) {
d->wbecnt = d->buf[1] << 24 | d->buf[2] << 16 |
d->buf[3] << 8 | d->buf[4];
TRACE ("sdcard%d: set write block erase count %u\n", d->unit, d->wbecnt);
reply = 0;
d->count = 0;
}
break;
case CMD_SEND_CSD: /* Get card data */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7) {
/* Send reply */
TRACE ("sdcard%d: send media size %u sectors\n",
d->unit, d->kbytes * 2);
reply = 0;
d->limit = 16 + 3;
d->count = 1;
d->buf[0] = 0;
d->buf[1] = DATA_START_BLOCK;
d->buf[2+0] = 1 << 6; /* SDC ver 2.00 */
d->buf[2+1] = 0;
d->buf[2+2] = 0;
d->buf[2+3] = 0;
d->buf[2+4] = 0;
d->buf[2+5] = 0;
d->buf[2+6] = 0;
d->buf[2+7] = 0;
d->buf[2+8] = (d->kbytes / 512 - 1) >> 8;
d->buf[2+9] = d->kbytes / 512 - 1;
d->buf[2+10] = 0;
d->buf[2+11] = 0;
d->buf[2+12] = 0;
d->buf[2+13] = 0;
d->buf[2+14] = 0;
d->buf[2+15] = 0;
d->buf[d->limit - 1] = 0xFF;
d->buf[d->limit] = 0xFF;
}
break;
case CMD_READ_SINGLE: /* Read block */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7) {
/* Send reply */
reply = 0;
d->offset = d->buf[1] << 24 | d->buf[2] << 16 |
d->buf[3] << 8 | d->buf[4];
TRACE ("sdcard%d: read offset %#x, length %u kbytes\n",
d->unit, d->offset, d->blen);
d->limit = d->blen + 3;
d->count = 1;
d->buf[0] = 0;
d->buf[1] = DATA_START_BLOCK;
sdcard_read_data (d->fd, d->offset, &d->buf[2], d->blen);
d->buf[d->limit - 1] = 0xFF;
d->buf[d->limit] = 0xFF;
}
break;
case CMD_READ_MULTIPLE: /* Read multiple blocks */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7) {
/* Send reply */
reply = 0;
d->read_multiple = 1;
d->offset = d->buf[1] << 24 | d->buf[2] << 16 |
d->buf[3] << 8 | d->buf[4];
TRACE ("sdcard%d: read offset %#x, length %u kbytes\n",
d->unit, d->offset, d->blen);
d->limit = d->blen + 3;
d->count = 1;
d->buf[0] = 0;
d->buf[1] = DATA_START_BLOCK;
sdcard_read_data (d->fd, d->offset, &d->buf[2], d->blen);
d->buf[d->limit - 1] = 0xFF;
d->buf[d->limit] = 0xFF;
}
break;
case CMD_WRITE_SINGLE: /* Write block */
if (d->count >= sizeof (d->buf))
break;
d->buf [d->count++] = data;
if (d->count == 7) {
/* Accept command */
reply = 0;
d->offset = d->buf[1] << 24 | d->buf[2] << 16 |
d->buf[3] << 8 | d->buf[4];
TRACE ("sdcard%d: write offset %#x\n", d->unit, d->offset);
} else if (d->count == 7 + d->blen + 2 + 2) {
if (d->buf[7] == DATA_START_BLOCK) {
/* Accept data */
reply = 0x05;
d->offset = d->buf[1] << 24 | d->buf[2] << 16 |
d->buf[3] << 8 | d->buf[4];
sdcard_write_data (d->fd, d->offset, &d->buf[8], d->blen);
TRACE ("sdcard%d: write data, length %u kbytes\n", d->unit, d->blen);
} else {
/* Reject data */
reply = 4;
TRACE ("sdcard%d: reject write data, tag=%02x\n", d->unit, d->buf[7]);
}
}
break;
case CMD_WRITE_MULTIPLE: /* Write multiple blocks */
if (d->count >= 7)
break;
d->buf [d->count++] = data;
if (d->count == 7) {
/* Accept command */
reply = 0;
d->offset = d->buf[1] << 24 | d->buf[2] << 16 |
d->buf[3] << 8 | d->buf[4];
TRACE ("sdcard%d: write multiple offset %#x\n", d->unit, d->offset);
d->count = 0;
}
break;
case WRITE_MULTIPLE_TOKEN: /* Data for write-miltiple */
if (d->count >= sizeof (d->buf))
break;
d->buf [d->count++] = data;
if (d->count == 2 + d->blen + 2) {
/* Accept data */
reply = 0x05;
sdcard_write_data (d->fd, d->offset, &d->buf[1], d->blen);
TRACE ("sdcard%d: write sector %u, length %u kbytes\n",
d->unit, d->offset / 512, d->blen);
d->offset += 512;
d->count = 0;
}
break;
case CMD_STOP: /* Stop read-multiple sequence */
if (d->count > 1)
break;
d->read_multiple = 0;
reply = 0;
break;
case 0: /* Reply */
if (d->count <= d->limit) {
reply = d->buf [d->count++];
break;
}
if (d->read_multiple) {
/* Next read-multiple block. */
d->offset += d->blen;
d->count = 1;
sdcard_read_data (d->fd, d->offset, &d->buf[2], d->blen);
reply = 0;
}
break;
default: /* Ignore */
break;
}
}
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;
}
