Display test

display.c

@@ -0,0 +1,89 @@
+#include <stdint.h>
+#include <pic32mx.h>
+#include "snake.h" 
+
+#define DISPLAY_CHANGE_TO_COMMAND_MODE (PORTFCLR = 0x10)
+#define DISPLAY_CHANGE_TO_DATA_MODE (PORTFSET = 0x10)
+
+#define DISPLAY_ACTIVATE_RESET (PORTGCLR = 0x200)
+#define DISPLAY_DO_NOT_RESET (PORTGSET = 0x200)
+
+#define DISPLAY_ACTIVATE_VDD (PORTFCLR = 0x40)
+#define DISPLAY_ACTIVATE_VBAT (PORTFCLR = 0x20)
+
+#define DISPLAY_TURN_OFF_VDD (PORTFSET = 0x40)
+#define DISPLAY_TURN_OFF_VBAT (PORTFSET = 0x20)
+
+void quicksleep(int cyc) {
+	int i;
+	for(i = cyc; i > 0; i--);
+}
+
+void display_init(void){
+	DISPLAY_CHANGE_TO_COMMAND_MODE;
+	quicksleep(10);
+	DISPLAY_ACTIVATE_VDD;
+	quicksleep(1000000);
+
+	spi_send_recv(0xAE);
+	DISPLAY_ACTIVATE_RESET;
+	quicksleep(10);
+	DISPLAY_DO_NOT_RESET;
+	quicksleep(10);
+
+	spi_send_recv(0x8D);
+	spi_send_recv(0x14);
+
+	spi_send_recv(0xD9);
+	spi_send_recv(0xF1);
+
+	DISPLAY_ACTIVATE_VBAT;
+	quicksleep(10000000);
+
+	spi_send_recv(0xA1);
+	spi_send_recv(0xC8);
+
+	spi_send_recv(0xDA);
+	spi_send_recv(0x20);
+
+	spi_send_recv(0xAF);
+}
+
+void display_string(int line, char *s) {
+	int i;
+	if(line < 0 || line >= 4)
+		return;
+	if(!s)
+		return;
+
+	for(i = 0; i < 16; i++)
+		if(*s) {
+			textbuffer[line][i] = *s;
+			s++;
+		} else
+			textbuffer[line][i] = ' ';
+}
+
+void display_update(void) {
+	int i, j, k;
+	int c;
+	for(i = 0; i < 4; i++) {
+		DISPLAY_CHANGE_TO_COMMAND_MODE;
+		spi_send_recv(0x22);
+		spi_send_recv(i);
+
+		spi_send_recv(0x0);
+		spi_send_recv(0x10);
+
+		DISPLAY_CHANGE_TO_DATA_MODE;
+
+		for(j = 0; j < 16; j++) {
+			c = textbuffer[i][j];
+			if(c & 0x80)
+				continue;
+
+			for(k = 0; k < 8; k++)
+				spi_send_recv(font[c*8 + k]);
+		}
+	}
+}

main.c

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+#include <stdint.h>
+#include <pic32mx.h>
+#include "snake.h" 
+
+int main(void){
+	    /*
+	  This will set the peripheral bus clock to the same frequency
+	  as the sysclock. That means 80 MHz, when the microcontroller
+	  is running at 80 MHz. Changed 2017, as recommended by Axel.
+	*/
+	SYSKEY = 0xAA996655;  /* Unlock OSCCON, step 1 */
+	SYSKEY = 0x556699AA;  /* Unlock OSCCON, step 2 */
+	while(OSCCON & (1 << 21)); /* Wait until PBDIV ready */
+	OSCCONCLR = 0x180000; /* clear PBDIV bit <0,1> */
+	while(OSCCON & (1 << 21));  /* Wait until PBDIV ready */
+	SYSKEY = 0x0;  /* Lock OSCCON */
+
+	/* Set up output pins */
+	AD1PCFG = 0xFFFF;
+	ODCE = 0x0;
+	TRISECLR = 0xFF;
+	PORTE = 0x0;
+
+	/* Output pins for display signals */
+	PORTF = 0xFFFF;
+	PORTG = (1 << 9);
+	ODCF = 0x0;
+	ODCG = 0x0;
+	TRISFCLR = 0x70;
+	TRISGCLR = 0x200;
+
+	/* Set up input pins */
+	TRISDSET = (1 << 8);
+	TRISFSET = (1 << 1);
+
+	/* Set up SPI as master */
+	SPI2CON = 0;
+	SPI2BRG = 4;
+	/* SPI2STAT bit SPIROV = 0; */
+	SPI2STATCLR = 0x40;
+	/* SPI2CON bit CKP = 1; */
+        SPI2CONSET = 0x40;
+	/* SPI2CON bit MSTEN = 1; */
+	SPI2CONSET = 0x20;
+	/* SPI2CON bit ON = 1; */
+	SPI2CONSET = 0x8000;
+
+	display_init();
+	display_string(0, "TEST");
+	display_update();
+	return;
+}

snake.h

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+#include <stdint.h>
+#include <pic32mx.h>
+#include "snake.h" 
+
+uint8_t spi_send_recv(uint8_t data);
+extern char textbuffer[4][16];
+
+int main(void);
+void quicksleep(int cyc);
+void display_init(void);
+void display_string(int line, char *s);
+void display_update(void);
+