game-ctrl merged

game-ctrl/displayDriver.c

@@ -0,0 +1,57 @@
+#include "displayDriver.h"
+#include "led.h"
+#include "canvas.h"
+#include <msp430g2553.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+
+
+inline static void spiSendOctet(uint8_t v) {
+  // wait for TX buffer empty
+  while (!(UC0IFG & UCB0TXIFG));
+  // load octet into TX buffer
+  UCB0TXBUF = v;
+}
+
+void displayDriverTransferCanvas() {
+  // wait for signal waiting for data
+  while ((P1IN & BIT3) == 0);
+
+  for (uint8_t i = 0; i < canvas.size; i++) {
+    if ((*((canvas.canvas)+i) & 0x80) != 0) {
+      *((canvas.canvas)+i) &= ~0x80;
+      spiSendOctet(i);
+      spiSendOctet(*((canvas.canvas)+i));
+    }
+  }
+  spiSendOctet(0xfe);
+}
+
+void displayDriverInit() {
+  // SPI in master mode
+  UCB0CTL0 = UCMST;
+  // SPI timing config
+  UCB0CTL1 = UCSSEL_3;
+  // Faster than 8 ends up in strange communication errors
+  // between the both MCUs.
+  // With 8 the transfer of a complete 110 pixel canvas takes
+  // about 720us.
+  UCB0BR0 = 8; 
+  UCB0BR1 = 0;
+
+  // BIT5: UCB0CLK
+  // BIT6: UCB0SOMI
+  // BIT7: UCB0SIMO
+  P1SEL |= BIT5 | BIT6 | BIT7;
+  P1SEL2 |= BIT5 | BIT6 | BIT7;
+  P1DIR |= BIT5 | BIT7;
+
+  // P1.3 is signal line
+  P1DIR &= ~BIT3;
+
+  // enable SPI module
+  UCB0CTL1 &= ~UCSWRST;
+}
+
+