added uart test to projects

projects/rgb_random_wander/lib/README.md

@@ -1,8 +0,0 @@
-AVR utils library
-=================
-
-This is my ever-evolving library (not only) for AVR programming.
-
-When I'm done with a project, I copy the current library to the project, so it doesn't break when I do further improvements.
-
-Each library file contains a large comment block explaining it's function.

projects/uart_test/Makefile

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+## === CPU settings ===
+# CPU type
+MCU	= atmega328p
+# CPU frequency
+F_CPU = 16000000
+# Fuses
+LFUSE = 0xFF
+HFUSE = 0xDE
+EFUSE = 0x05
+
+
+## === Source files ===
+# Main C file
+MAIN = main.c
+# Extra C files in this folder
+LOCAL_SOURCE =
+
+# Library directory (with C files)
+EXTRA_SOURCE_DIR = lib/
+# C files in the library directory
+EXTRA_SOURCE_FILES = uart.c
+
+
+## === Programmer ===
+PROGRAMMER_TYPE = arduino
+PROGRAMMER_ARGS = -b 57600 -P /dev/ttyUSB0
+
+
+## === C flags ===
+
+CFLAGS = -std=gnu99 -mmcu=$(MCU) -DF_CPU=$(F_CPU)UL -I. -I$(EXTRA_SOURCE_DIR)
+CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
+CFLAGS += -Wall -Wno-main -Wno-strict-prototypes -Wno-comment
+CFLAGS += -g2 -Wextra -Wfatal-errors -Wno-unused-but-set-variable
+CFLAGS += -ffunction-sections -fdata-sections -Wl,--gc-sections -Wl,--relax
+# CFLAGS += -lm  ## Math
+# CFLAGS += -Wl,-u,vfprintf -lprintf_flt -lm  ## for floating-point printf
+# CFLAGS += -Wl,-u,vfprintf -lprintf_min      ## for smaller printf
+CFLAGS_BUILD = $(CFLAGS) -Os
+
+
+# ---------------------------------------------------------------------------
+
+## Defined programs / locations
+CC = avr-gcc
+OBJCOPY = avr-objcopy
+OBJDUMP = avr-objdump
+AVRSIZE = avr-size
+AVRDUDE = avrdude
+
+## === File lists ===
+TARGET = $(strip $(basename $(MAIN)))
+SRC1 = $(TARGET).c
+SRC = $(SRC1)
+EXTRA_SOURCE = $(addprefix $(EXTRA_SOURCE_DIR), $(EXTRA_SOURCE_FILES))
+SRC += $(EXTRA_SOURCE)
+SRC += $(LOCAL_SOURCE)
+
+HEADERS = $(SRC:.c=.h)
+OBJ = $(SRC:.c=.o)
+
+
+## === File generation ===
+all: $(TARGET).hex size
+pre: $(TARGET).pre
+
+%.hex: %.elf
+	$(OBJCOPY) -R .eeprom -O ihex $< $@
+
+%.elf: $(SRC)
+	$(CC) $(CFLAGS_BUILD) $(SRC) --output $@
+
+%.pre: $(SRC1)
+	$(CC) $(CFLAGS) -E $(SRC1) --output $@
+
+%.eeprom: %.elf
+	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O ihex $< $@
+
+%.lst: %.elf
+	$(OBJDUMP) -S $< > $@
+
+# Show debug info
+debug:
+	@echo
+	@echo "Source files:"   $(SRC)
+	@echo "MCU, F_CPU, BAUD:"  $(MCU), $(F_CPU), $(BAUD)
+	@echo
+
+
+# Disassemble the ELF
+disassemble: $(TARGET).lst
+dis: disassemble
+lst: disassemble
+
+# Make eeprom file
+eeprom: $(TARGET).eeprom
+
+# Show how big the resulting program is
+size:  $(TARGET).elf
+	$(AVRSIZE) -C --mcu=$(MCU) $(TARGET).elf
+
+# Clean all produced trash
+clean:
+	rm -f $(TARGET).elf $(TARGET).hex $(TARGET).obj \
+	$(TARGET).o $(TARGET).d $(TARGET).eep $(TARGET).lst \
+	$(TARGET).lss $(TARGET).sym $(TARGET).map $(TARGET)~ \
+	$(TARGET).eeprom
+
+# Clean all trash
+purge:
+	rm -f *.elf *.hex *.obj *.o *.d *.eep *.lst *.lss *.sym *.map *~
+
+
+## === avrdude ===
+
+flash: $(TARGET).hex
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -U flash:w:$<
+
+flashe: $(TARGET).eeprom
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -U eeprom:w:$<
+
+shell:
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -nt
+
+
+# === fuses ===
+
+FUSE_STRING = -U lfuse:w:$(LFUSE):m -U hfuse:w:$(HFUSE):m -U efuse:w:$(EFUSE):m
+
+fuses:
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) \
+	           $(PROGRAMMER_ARGS) $(FUSE_STRING)
+show_fuses:
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -nv
+
+set_default_fuses:  FUSE_STRING = -U lfuse:w:$(LFUSE):m -U hfuse:w:$(HFUSE):m -U efuse:w:$(EFUSE):m
+set_default_fuses:  fuses

projects/uart_test/lib/meta.h

@@ -0,0 +1,6 @@
+#pragma once
+
+/** Weird constructs for the compiler */
+
+// general macros
+#define SECTION(pos) __attribute__((naked, used, section(pos)))

projects/uart_test/lib/uart.c

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+#include <avr/io.h>
+#include <avr/pgmspace.h>
+#include <util/delay.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "uart.h"
+
+void _uart_init_do(uint16_t ubrr) {
+	/*Set baud rate */
+	UBRR0H = (uint8_t) (ubrr >> 8);
+	UBRR0L = (uint8_t) ubrr;
+
+	// Enable Rx and Tx
+	UCSR0B = (1 << RXEN0) | (1 << TXEN0);
+
+	// 8-bit data, 1 stop bit
+	UCSR0C = (0b11 << UCSZ00);
+}
+
+
+/** Enable or disable RX ISR */
+void uart_isr_rx(bool yes)
+{
+	if(yes) {
+		UCSR0B |= (1 << RXCIE0);
+	} else {
+		UCSR0B &= ~(1 << RXCIE0);
+	}
+}
+
+/** Enable or disable TX ISR (1 byte is sent) */
+void uart_isr_tx(bool yes)
+{
+	if(yes) {
+		UCSR0B |= (1 << TXCIE0);
+	} else {
+		UCSR0B &= ~(1 << TXCIE0);
+	}
+}
+
+/** Enable or disable DRE ISR (all is sent) */
+void uart_isr_dre(bool yes)
+{
+	if(yes) {
+		UCSR0B |= (1 << UDRIE0);
+	} else {
+		UCSR0B &= ~(1 << UDRIE0);
+	}
+}
+
+
+
+
+/** Send byte over UART */
+void uart_tx(uint8_t data)
+{
+	// Wait for transmit buffer
+	while (!uart_tx_ready());
+	// send it
+	UDR0 = data;
+}
+
+/** Send string over UART */
+void uart_puts(const char* str)
+{
+	while (*str) {
+		uart_tx(*str++);
+	}
+}
+
+/** Send progmem string over UART */
+void uart_puts_pgm(const char* str)
+{
+	char c;
+	while ((c = pgm_read_byte(str++))) {
+		uart_tx(c);
+	}
+}
+
+/** Receive one byte over UART */
+uint8_t uart_rx()
+{
+	// Wait for data to be received
+	while (!uart_rx_ready());
+	// Get and return received data from buffer
+	return UDR0;
+}
+
+/** Clear receive buffer */
+void uart_flush()
+{
+	uint8_t dummy;
+	while (UCSR0A & (1 << RXC0))
+		dummy = UDR0;
+}
+

projects/uart_test/lib/uart.h

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+#pragma once
+
+#include <avr/io.h>
+#include <avr/pgmspace.h>
+#include <util/delay.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+/** Init UART for given baudrate */
+#define uart_init(baud) _uart_init_do(F_CPU / 16 / (baud) - 1)
+
+void _uart_init_do(uint16_t ubrr);
+
+/** Check if there's a byte in the RX register */
+#define uart_rx_ready() (0 != (UCSR0A & (1 << RXC0)))
+
+/** Check if transmission of everything is done */
+#define uart_tx_ready() (0 != (UCSR0A & (1 << UDRE0)))
+
+/** Enable or disable RX ISR */
+void uart_isr_rx(bool enable);
+
+/** Enable or disable TX ISR (1 byte is sent) */
+void uart_isr_tx(bool enable);
+
+/** Enable or disable DRE ISR (all is sent) */
+void uart_isr_dre(bool enable);
+
+/** Send byte over UART */
+#define uart_putc(data) uart_tx(data)
+void uart_tx(uint8_t data);
+
+/** Send string over UART */
+void uart_puts(const char* str);
+
+/** Send progmem string over UART */
+void uart_puts_pgm(const char* str);
+
+/** Receive one byte over UART */
+uint8_t uart_rx();
+
+/** Clear receive buffer */
+void uart_flush();

projects/uart_test/main.c

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+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/pgmspace.h>
+#include <avr/interrupt.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "lib/meta.h"
+#include "lib/uart.h"
+
+const char str[] PROGMEM = "Hello UART!\r\n";
+
+
+// Echo, but with ROT13.
+ISR(USART_RX_vect)
+{
+	char c = uart_rx();
+
+	if (c == 13) {
+		uart_tx(10);
+		uart_tx(13);
+		return;
+	}
+
+	if ((c >= 'a' && c <= 'm') || (c >= 'A' && c <= 'M')) {
+			c += 13;
+	} else
+	if ((c >= 'n' && c <= 'z') || (c >= 'N' && c <= 'Z')) {
+			c -= 13;
+	}
+
+	uart_tx(c);
+}
+
+
+void SECTION(".init8") init()
+{
+	uart_init(9600);
+	uart_isr_rx(1);
+	sei();
+}
+
+
+void main()
+{
+	uart_puts_pgm(str);
+
+	while(1);
+}