1 files changed, 56 insertions, 0 deletions

diff --git a/src/inc/spi/spi.c b/src/inc/spi/spi.c
new file mode 100755
index 0000000..b04fe7e
--- /dev/null
+++ b/src/inc/spi/spi.c
@@ -0,0 +1,56 @@
+#include "spi.h"
+
+void spi_init()
+{
+  // setup SPI-Port
+  DDR_SPI   = (1<<DD_MOSI) | (1<<DD_SS) | (1<<DD_SCK);
+  PORT_SPI |=  (1<<DD_SS);
+
+  // SPI Control Register (SPCR)
+  // SPI Enable=1 | Data Order=LSB | SPI_Master=1 (!make SS stay HIGH!)
+  // SPCR |= (1<<SPE) | (1<<DORD) | (1<<MSTR) | (1<<CPOL) | (1<<CPHA) | (1<<SPR1) | (1<<SPR0);
+  // (1<<DORD) - would be LSB-mode (, but we need MSB-mode!)
+  SPCR  = (1<<SPE) | (1<<MSTR); //  (1<<SPR1) | (1<<SPR0)
+  spi_setspeed(SPICLK_DEFAULT);
+  // setup SPI options
+  /// SPSR &= ~(1<<SPI2X); // do not use SPI speed-doubler
+}
+
+void spi_setspeed(SPICLK speed)
+{
+  if(speed < 4) // nominal clock speeds
+  {
+    SPSR &= ~(1<<SPI2X); // do not use SPI speed-doubler
+    SPCR |= speed;
+  }
+  else // use SPI2X
+  {
+    SPSR |= (1<<SPI2X);  // use SPI speed-doubler
+    SPCR |= (speed - 0x4);
+  }
+  _delay_ms(2);
+}
+
+void spi_putc(unsigned char c)
+{
+  /// uart_putc('>');
+  /// uart_putc(c);
+  /// uart_putc('\n');
+  SPDR = c;
+  loop_until_bit_is_set(SPSR, SPIF);
+  /// stdout_put_string(uart_putc, "- [done]\n");
+}
+
+unsigned char spi_getc()
+{
+  SPDR = 0xFF; // init receive register with value
+  /* Wait for reception complete */
+  while(!(SPSR & (1<<SPIF)));
+  /* Return data register */
+  return SPDR;
+  /// unsigned char c = SPDR;
+  /// uart_putc('<');
+  /// uart_putc(c);
+  /// uart_putc('\n');
+  /// return c;
+}