int main(void)
{
int counter = 0;
uint16_t rx_value = 0x42;
/* Setup Rx/Tx buffers for USART */
buffer_init(send_buffer,BUFFER_SIZE);
buffer_init(receive_buffer,BUFFER_SIZE);
clock_setup();
gpio_setup();
usart_setup();
usart_print_string("SPI-DMA Test\n\r");
spi_setup();
while (1) {
gpio_toggle(GPIOA, GPIO1);
#ifdef LOOPBACK
/* Print what is going to be sent on the SPI bus */
usart_print_string("Sending packet ");
usart_print_int(counter);
usart_print_string("\n\r");
spi_send(SPI1, (uint8_t) counter);
rx_value = spi_read(SPI1);
usart_print_string("Received packet ");
usart_print_int(rx_value);
usart_print_string("\n\r");
counter++;
#else
/* This is a 1-byte "reset" command to SD card */
spi_send(SPI1, 0x40);
spi_send(SPI1, 0x00);
spi_send(SPI1, 0x00);
spi_send(SPI1, 0x00);
spi_send(SPI1, 0x00);
spi_send(SPI1, 0x95);
/* Read the byte that just came in (use a loopback between MISO and MOSI
* to get the same byte back)
*/
rx_value = spi_read(SPI1);
#endif
}
return 0;
}
int main(void)
{
int counter_tx = 0;
int counter_rx = 0;
cnt_state counter_state = TX_UP_RX_HOLD;
int i = 0;
/* Transmit and Receive packets, set transmit to index and receive to known
unused value to aid in debugging */
#if USE_16BIT_TRANSFERS
uint16_t tx_packet[16] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
uint16_t rx_packet[16] = {0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42,
0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42};
#else
uint8_t tx_packet[16] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
uint8_t rx_packet[16] = {0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42,
0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42};
#endif
transceive_status = DONE;
clock_setup();
gpio_setup();
usart_setup();
usart_print_string("SPI-DMA Test\n\r");
spi_setup();
dma_setup();
/* Blink the LED (PA8) on the board with every transmitted byte. */
while (1) {
/* LED on/off */
gpio_toggle(GPIOA, GPIO1);
/* Print what is going to be sent on the SPI bus */
usart_print_string("Sending packet (tx len: ");
usart_print_int(counter_tx);
usart_print_string(")\n\r");
for (i = 0; i < counter_tx; i++)
{
usart_print_int(tx_packet[i]);
usart_print_string(" ");
}
usart_print_string("\r\n");
/* Start a transceive */
if (spi_dma_transceive(tx_packet, counter_tx, rx_packet, counter_rx)) {
usart_print_string("Attempted 0 length tx and rx packets\r\n");
}
/* Wait until transceive complete.
* This checks the state flag as well as follows the
* procedure on the Reference Manual (RM0008 rev 14
* Section 25.3.9 page 692, the note.)
*/
while (transceive_status != DONE)
;
while (!(SPI_SR(SPI2) & SPI_SR_TXE))
;
while (SPI_SR(SPI2) & SPI_SR_BSY)
;
/* Print what was received on the SPI bus */
usart_print_string("Received Packet (rx len ");
usart_print_int(counter_rx);
usart_print_string(")\n\r");
for (i = 0; i < 16; i++) {
usart_print_int(rx_packet[i]);
usart_print_string(" ");
}
usart_print_string("\r\n\r\n");
/* Update counters
* If we use the loopback method, we can not
* have a rx length longer than the tx length.
* Testing rx lengths longer than tx lengths
* requires an actual slave device that will
* return data.
*/
switch (counter_state) {
case TX_UP_RX_HOLD:
counter_tx++;
if (counter_tx > 15) {
counter_state = TX_HOLD_RX_UP;
}
break;
case TX_HOLD_RX_UP:
counter_rx++;
if (counter_rx > 15) {
counter_state = TX_DOWN_RX_DOWN;
}
break;
case TX_DOWN_RX_DOWN:
counter_tx--;
counter_rx--;
if (counter_tx < 1) {
counter_state = TX_UP_RX_HOLD;
}
break;
default:
;
}
/* Reset receive buffer for consistency */
for (i = 0; i < 16; i++) {
rx_packet[i] = 0x42;
}
}
return 0;
}
// write a program-memory string to usart
void usart_dumpvar(PGM_P name, int32_t value) {
usart_print_pstr(name);
usart_print_pstr(PSTR(": "));
usart_print_int(value);
usart_print_ln();
}
