Added parts of the avr library

software/AVR8/.clang_complete

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+-I/usr/avr/include
+-D__AVR_ATmega328__

software/AVR8/.gitignore

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+*.o
+*.elf
+*.hex

software/AVR8/Makefile

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+AVRMCU ?= atmega8
+F_CPU ?= 16000000
+ISPPORT ?= /dev/ttyUSB0
+
+VERSION = 0.1
+
+HEADERS =
+SRC = main.c
+TARGET = sss7
+OBJDIR = bin
+
+CC = avr-gcc
+OBJCOPY = avr-objcopy
+OBJDUMP = avr-objdump
+SIZE = avr-size
+
+OBJ = $(SRC:%.c=$(OBJDIR)/$(AVRMCU)/%.o)
+
+CFLAGS = -Os -Wall -Wstrict-prototypes
+CFLAGS += -ffunction-sections -fdata-sections
+CFLAGS += -fshort-enums -fpack-struct -funsigned-char -funsigned-bitfields
+CFLAGS += -mmcu=$(AVRMCU) -DF_CPU=$(F_CPU)UL -DVERSION=$(VERSION)
+
+LDFLAGS = -mmcu=$(AVRMCU) -Wl,--gc-sections
+
+all: start $(OBJDIR)/$(AVRMCU)/$(TARGET).hex size
+	@echo ":: Done !"
+
+start:
+	@echo "AS5043 demo version $(VERSION)"
+	@echo "=============================="
+	@echo ":: Building for $(AVRMCU)"
+	@echo ":: MCU operating frequency is $(F_CPU)Hz"
+
+$(OBJDIR)/$(AVRMCU)/%.o : %.c $(HEADERS)
+	@mkdir -p $$(dirname $@)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+$(OBJDIR)/$(AVRMCU)/$(TARGET).elf : $(OBJ)
+	$(CC) $(LDFLAGS) $+ -o $@
+
+$(OBJDIR)/$(AVRMCU)/$(TARGET).hex : $(OBJDIR)/$(AVRMCU)/$(TARGET).elf
+	$(OBJCOPY) -O ihex $< $@
+
+size : $(OBJDIR)/$(AVRMCU)/$(TARGET).elf
+	@echo
+	@$(SIZE) --mcu=$(AVRMCU) -C $(OBJDIR)/$(AVRMCU)/$(TARGET).elf
+	@echo
+
+clean :
+	@rm -rf $(OBJDIR)
+
+flash : all
+	avrdude -c arduino \
+		-p $(AVRMCU) -P $(ISPPORT) \
+        -U flash:w:$(OBJDIR)/$(AVRMCU)/$(TARGET).hex
+
+test : flash
+	screen $(ISPPORT) 38400

software/AVR8/main.c

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+
+
+#include "sss7.h"
+
+
+int main(void) {
+
+
+}

software/AVR8/sss7.c

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+#include "sss7.h"
+
+#include <avr/interrupt.h>
+#include <util/crc16.h>
+#include <string.h>
+
+volatile enum sss7State sss7_state;
+
+uint8_t sss7_rx_buffer[2][SSS7_PAYLOAD_SIZE];
+uint8_t sss7_rx_active_buffer;
+uint8_t sss7_rx_pos;
+
+uint8_t sss7_tx_buffer[SSS7_PAYLOAD_SIZE];
+uint8_t sss7_tx_pos;
+uint8_t sss7_tx_crc;
+uint8_t sss7_tx_failed;
+uint8_t sss7_tx_last_byte = 0;
+
+void sss7_init() {
+	sss7_state = SSS7_IDLE;
+
+	sss7_rx_pos = 0;
+	sss7_rx_oldest_buffer = 0;
+	sss7_rx_active_buffer = 0;
+
+	sss7_tx_pos = 0;
+	sss7_tx_crc = 0;
+	sss7_tx_failed = 0;
+}
+
+inline uint8_t sss7_payload_crc(uint8_t buffer[SSS7_PAYLOAD_SIZE]) {
+	uint8_t crc = 0;
+	for(uint8_t i = 0; i < SSS7_PAYLOAD_SIZE; i++) {
+		crc = _crc_ibutton_update(crc, buffer[i]);
+	}
+	return crc;
+}
+
+void sss7_send(uint8_t msg[SSS7_PAYLOAD_SIZE]) {
+	// Check that we can send, because we will overwritte the buffer
+	if(sss7_state != SSS7_IDLE) {
+		sss7_tx_failed = 1;
+		return;
+	}
+
+	memcpy(sss7_tx_buffer, msg, SSS7_PAYLOAD_SIZE);
+
+	sss7_tx_pos = 0;
+	sss7_tx_crc = sss7_payload_crc(sss7_tx_buffer);
+
+	// Commit to send state
+	sss7_state = SSS7_TX_HEADER;
+	uart_sent_byte(SSS7_HEADER[0]);
+}
+
+void sss7_receive_byte() {
+	uint8_t byte = uart_get_byte();
+	uint8_t crc = 0;
+
+	switch(sss7_state) {
+		case SSS7_IDLE:
+			if(byte == SSS7_HEADER[0]) {
+				sss7_state = SSS7_RX_HEADER;
+			}
+			else {
+				sss7_state = SSS7_IDLE;
+			}
+		break;
+
+		case SSS7_RX_HEADER:
+			if(byte == SSS7_HEADER[1]) {
+				sss7_state = SSS7_RX_PAYLOAD;
+				sss7_rx_pos = 0;
+			}
+			else {
+				sss7_state = SSS7_IDLE;
+			}
+		break;
+
+		case SSS7_RX_PAYLOAD:
+			sss7_rx_buffer[sss7_rx_active_buffer][sss7_rx_pos] = byte;
+			sss7_rx_pos++;
+			if(sss7_rx_pos >= SSS7_PAYLOAD_SIZE) {
+				sss7_state = SSS7_RX_CRC;
+			}
+		break;
+
+		case SSS7_RX_CRC:
+			crc = sss7_payload_crc(sss7_rx_buffer[sss7_rx_active_buffer]);
+			if(byte == crc) {
+				sss7_rx_active_buffer = (sss7_rx_active_buffer + 1);
+			}
+			sss7_state = SSS7_IDLE;
+		break;
+
+		// all the TX states
+		default:
+			if(byte != sss7_tx_last_byte) {
+				sss7_state = SSS7_IDLE;
+				sss7_tx_failed = 1;
+			}
+		break;
+	}
+}
+
+void sss7_transmit_byte() {
+	uint8_t byte;
+	switch(sss7_state) {
+		case SSS7_TX_HEADER:
+			uart_sent_byte(SSS7_HEADER[1]);
+			sss7_state = SSS7_TX_PAYLOAD;
+			sss7_tx_pos = 0;
+		break;
+
+		case SSS7_TX_PAYLOAD:
+			byte = sss7_tx_buffer[sss7_tx_pos];
+			uart_sent_byte(byte);
+			sss7_tx_last_byte = byte;
+			sss7_tx_pos++;
+
+			if(sss7_tx_pos >= SSS7_PAYLOAD_SIZE) {
+				sss7_state = SSS7_TX_CRC;
+			}
+		break;
+
+		case SSS7_TX_CRC:
+			uart_sent_byte(sss7_tx_crc);
+			sss7_tx_last_byte = sss7_tx_crc;
+			sss7_state = SSS7_IDLE;
+		break;
+
+		//All the RX states
+		default:
+		break;
+	}
+}
+
+void sss7_get_received(uint8_t msg[SSS7_PAYLOAD_SIZE]) {
+	if(sss7_has_received()) {
+		memcpy(msg, sss7_rx_buffer[sss7_rx_oldest_buffer], SSS7_PAYLOAD_SIZE);
+		sss7_rx_oldest_buffer++;
+	};
+}

software/AVR8/sss7.h

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+#ifndef _SSS7_H_
+#define _SSS7_H_
+
+#include "stdint.h"
+
+enum sss7State {
+	SSS7_IDLE,
+	SSS7_TX_HEADER,
+	SSS7_TX_PAYLOAD,
+	SSS7_TX_CRC,
+
+	SSS7_RX_HEADER,
+	SSS7_RX_PAYLOAD,
+	SSS7_RX_CRC
+};
+
+const uint8_t SSS7_HEADER[] = {0xAA, 0xFE};
+
+#define SSS7_PAYLOAD_SIZE 16
+#define SSS7_RX_BUFFER_COUNT 2
+
+extern volatile enum sss7State sss7_state;
+extern uint8_t sss7_tx_failed;
+extern uint8_t sss7_rx_active_buffer;
+extern uint8_t sss7_rx_oldest_buffer;
+
+void sss7_init();
+
+static inline uint8_t sss7_can_send() {
+	return sss7_state == SSS7_IDLE;
+}
+
+void sss7_send(uint8_t msg[SSS7_PAYLOAD_SIZE]);
+
+static inline uint8_t sss7_send_failed() {
+	return sss7_state != SSS7_IDLE && sss7_tx_failed;
+}
+
+static inline uint8_t sss7_has_received() {
+	return sss7_rx_oldest_buffer < sss7_rx_active_buffer;
+}
+
+
+
+void sss7_get_received(uint8_t msg[SSS7_PAYLOAD_SIZE]);
+
+#endif