avr example

sys/avr/atmega328/main.c

@@ -0,0 +1,156 @@
+/*
+	main.c
+	
+	AVR Test Project
+	This project will use 4-Wire SW SPI
+
+*/
+
+
+#include <avr/io.h>
+#include <u8g2.h>
+#include <util/delay.h>
+
+#define DISPLAY_CLK_DIR DDRB
+#define DISPLAY_CLK_PORT PORTB
+#define DISPLAY_CLK_PIN 5
+
+#define DISPLAY_DATA_DIR DDRB
+#define DISPLAY_DATA_PORT PORTB
+#define DISPLAY_DATA_PIN 3
+
+#define DISPLAY_CS_DIR DDRB
+#define DISPLAY_CS_PORT PORTB
+#define DISPLAY_CS_PIN 2
+
+#define DISPLAY_DC_DIR DDRB
+#define DISPLAY_DC_PORT PORTB
+#define DISPLAY_DC_PIN 1
+
+#define DISPLAY_RESET_DIR DDRB
+#define DISPLAY_RESET_PORT PORTB
+#define DISPLAY_RESET_PIN 0
+
+
+
+
+#define P_CPU_NS (1000000000UL / F_CPU)
+
+u8g2_t u8g2;
+
+uint8_t u8x8_avr_delay(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
+{
+	uint8_t cycles;
+
+	switch(msg)
+	{
+		case U8X8_MSG_DELAY_NANO:     // delay arg_int * 1 nano second
+			// At 20Mhz, each cycle is 50ns, the call itself is slower.
+			break;
+		case U8X8_MSG_DELAY_100NANO:    // delay arg_int * 100 nano seconds
+			// Approximate best case values...
+#define CALL_CYCLES 26UL
+#define CALC_CYCLES 4UL
+#define RETURN_CYCLES 4UL
+#define CYCLES_PER_LOOP 4UL
+
+			cycles = (100UL * arg_int) / (P_CPU_NS * CYCLES_PER_LOOP);
+
+			if(cycles > CALL_CYCLES + RETURN_CYCLES + CALC_CYCLES) 
+				break;
+
+			__asm__ __volatile__ (
+			"1: sbiw %0,1" "\n\t" // 2 cycles
+			"brne 1b" : "=w" (cycles) : "0" (cycles) // 2 cycles
+			);
+			break;
+		case U8X8_MSG_DELAY_10MICRO:    // delay arg_int * 10 micro seconds
+			for(int i=0 ; i < arg_int ; i++)
+				_delay_us(10);
+			break;
+		case U8X8_MSG_DELAY_MILLI:      // delay arg_int * 1 milli second
+			for(int i=0 ; i < arg_int ; i++)
+				_delay_ms(1);
+			break;
+		default:
+			return 0;
+	}
+	return 1;
+}
+
+
+uint8_t u8x8_avr_gpio_and_delay(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
+{
+	// Re-use library for delays
+
+	switch(msg)
+	{
+		case U8X8_MSG_GPIO_AND_DELAY_INIT:  // called once during init phase of u8g2/u8x8
+			DISPLAY_CLK_DIR |= 1<<DISPLAY_CLK_PIN;
+			DISPLAY_DATA_DIR |= 1<<DISPLAY_DATA_PIN;
+			DISPLAY_CS_DIR |= 1<<DISPLAY_CS_PIN;
+			DISPLAY_DC_DIR |= 1<<DISPLAY_DC_PIN;
+			DISPLAY_RESET_DIR |= 1<<DISPLAY_RESET_PIN;
+			break;              // can be used to setup pins
+		case U8X8_MSG_GPIO_SPI_CLOCK:        // Clock pin: Output level in arg_int
+			if(arg_int)
+				DISPLAY_CLK_PORT |= (1<<DISPLAY_CLK_PIN);
+			else
+				DISPLAY_CLK_PORT &= ~(1<<DISPLAY_CLK_PIN);
+			break;
+		case U8X8_MSG_GPIO_SPI_DATA:        // MOSI pin: Output level in arg_int
+			if(arg_int)
+				DISPLAY_DATA_PORT |= (1<<DISPLAY_DATA_PIN);
+			else
+				DISPLAY_DATA_PORT &= ~(1<<DISPLAY_DATA_PIN);
+			break;
+		case U8X8_MSG_GPIO_CS:        // CS (chip select) pin: Output level in arg_int
+			if(arg_int)
+				DISPLAY_CS_PORT |= (1<<DISPLAY_CS_PIN);
+			else
+				DISPLAY_CS_PORT &= ~(1<<DISPLAY_CS_PIN);
+			break;
+		case U8X8_MSG_GPIO_DC:        // DC (data/cmd, A0, register select) pin: Output level in arg_int
+			if(arg_int)
+				DISPLAY_DC_PORT |= (1<<DISPLAY_DC_PIN);
+			else
+				DISPLAY_DC_PORT &= ~(1<<DISPLAY_DC_PIN);
+			break;
+		
+		case U8X8_MSG_GPIO_RESET:     // Reset pin: Output level in arg_int
+			if(arg_int)
+				DISPLAY_RESET_PORT |= (1<<DISPLAY_RESET_PIN);
+			else
+				DISPLAY_RESET_PORT &= ~(1<<DISPLAY_RESET_PIN);
+			break;
+		default:
+			if (u8x8_avr_delay(u8x8, msg, arg_int, arg_ptr))	// check for any delay msgs
+				return 1;
+			u8x8_SetGPIOResult(u8x8, 1);      // default return value
+			break;
+	}
+	return 1;
+}
+
+int main(void)
+{
+	/*
+		Select a setup procedure for your display from here:
+		1. Arg: Address of an empty u8g2 structure
+		2. Arg: Usually U8G2_R0, others are listed here: https://github.com/olikraus/u8g2/wiki/u8g2reference#carduino-example
+		3. Arg: Protocol procedure (u8g2-byte), list is here: https://github.com/olikraus/u8g2/wiki/Porting-to-new-MCU-platform#communication-callback-eg-u8x8_byte_hw_i2c
+		4. Arg: Defined in this code itself (see above)
+	*/
+	u8g2_Setup_st7565_ea_dogm132_f( &u8g2, U8G2_R0, u8x8_byte_4wire_sw_spi, u8x8_avr_gpio_and_delay );
+	u8g2_InitDisplay(&u8g2);
+	u8g2_SetPowerSave(&u8g2, 0);
+	
+	/* full buffer example, setup procedure ends in _f */
+	u8g2_ClearBuffer(&u8g2);
+	u8g2_SetFont(&u8g2, u8g2_font_ncenB14_tr);
+	u8g2_DrawStr(&u8g2, 1, 18, "U8g2 on AVR");
+	u8g2_SendBuffer(&u8g2);
+		
+	while(1){
+	}
+}