Added software I2C on timer TIM2

si7005_softi2c/uart.c

@@ -0,0 +1,169 @@
+/*
+ * blinky.c
+ *
+ * Copyright 2014 Edward V. Emelianoff <eddy@sao.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+
+#include "ports_definition.h"
+#include "uart.h"
+#include "interrupts.h"
+
+U8 UART_rx[UART_BUF_LEN]; // cycle buffer for received data
+U8 UART_rx_start_i = 0;   // started index of received data (from which reading starts)
+U8 UART_rx_cur_i = 0;     // index of current first byte in rx array (to which data will be written)
+
+/**
+ * Send one byte through UART
+ * @param byte - data to send
+ */
+void UART_send_byte(U8 byte){
+	while(!(UART2_SR & UART_SR_TXE)); // wait until previous byte transmitted
+	UART2_DR = byte;
+}
+
+void uart_write(char *str){
+	while(*str){
+		while(!(UART2_SR & UART_SR_TXE));
+		UART2_CR2 |= UART_CR2_TEN;
+		UART2_DR = *str++;
+	}
+}
+
+/**
+ * Read one byte from Rx buffer
+ * @param byte - where to store readed data
+ * @return 1 in case of non-empty buffer
+ */
+U8 UART_read_byte(U8 *byte){
+	if(UART_rx_start_i == UART_rx_cur_i) // buffer is empty
+		return 0;
+	*byte = UART_rx[UART_rx_start_i++];
+	check_UART_pointer(UART_rx_start_i);
+	return 1;
+}
+
+void printUint(U8 *val, U8 len){
+	unsigned long Number = 0;
+	U8 i = len;
+	char ch;
+	U8 decimal_buff[12]; // max len of U32 == 10 + \n + \0
+	if(len > 4 || len == 3 || len == 0) return;
+	for(i = 0; i < 12; i++)
+		decimal_buff[i] = 0;
+	decimal_buff[10] = '\n';
+	ch = 9;
+	switch(len){
+		case 1:
+			Number = *((U8*)val);
+			break;
+		case 2:
+			Number = *((U16*)val);
+		break;
+		case 4:
+			Number = *((unsigned long*)val);
+		break;
+	}
+	do{
+		i = Number % 10L;
+		decimal_buff[ch--] = i + '0';
+		Number /= 10L;
+	}while(Number && ch > -1);
+	uart_write((char*)&decimal_buff[ch+1]);
+}
+
+/**
+ * print signed long onto terminal
+ * max len = 10 symbols + 1 for "-" + 1 for '\n' + 1 for 0 = 13
+ */
+void print_long(long Number){
+	U8 i, L = 0;
+	char ch;
+	char decimal_buff[12];
+	decimal_buff[11] = 0;
+	ch = 11;
+	if(Number < 0){
+		Number = -Number;
+		L = 1;
+	}
+	do{
+		i = Number % 10L;
+		decimal_buff[--ch] = i + '0';
+		Number /= 10L;
+	}while(Number && ch > 0);
+	if(ch > 0 && L) decimal_buff[--ch] = '-';
+	uart_write(&decimal_buff[ch]);
+}
+
+U8 readInt(int *val){
+	unsigned long T = Global_time;
+	unsigned long R = 0;
+	int readed;
+	U8 sign = 0, rb, ret = 0, bad = 0;
+	do{
+		if(!UART_read_byte(&rb)) continue;
+		if(rb == '-' && R == 0){ // negative number
+			sign = 1;
+			continue;
+		}
+		if(rb < '0' || rb > '9') break; // number ends with any non-digit symbol that will be omitted
+		ret = 1; // there's at least one digit
+		R = R * 10L + rb - '0';
+		if(R > 0x7fff){ // bad value
+			R = 0;
+			bad = 0;
+		}
+	}while(Global_time - T < 10000); // wait no longer than 10s
+	if(bad || !ret) return 0;
+	readed = (int) R;
+	if(sign) readed *= -1;
+	*val = readed;
+	return 1;
+}
+
+void error_msg(char *msg){
+	uart_write("\nERROR: ");
+	uart_write(msg);
+	UART_send_byte('\n');
+}
+
+U8 U8toHEX(U8 val){
+	val &= 0x0f;
+	if(val < 10) val += '0';
+	else val += 'a' - 10;
+	return val;
+}
+
+void printUHEX(U8 val){
+	uart_write("0x");
+	UART_send_byte(U8toHEX(val>>4)); // MSB
+	UART_send_byte(U8toHEX(val));    // LSB
+}
+
+void uart_init(){
+	// PD5 - UART2_TX
+	PORT(UART_PORT, DDR) |= UART_TX_PIN;
+	PORT(UART_PORT, CR1) |= UART_TX_PIN;
+// Configure UART
+	// 8 bit, no parity, 1 stop (UART_CR1/3 = 0 - reset value)
+	// 57600 on 16MHz: BRR1=0x11, BRR2=0x06
+	UART2_BRR1 = 0x11; UART2_BRR2 = 0x06;
+	UART2_CR2 = UART_CR2_TEN | UART_CR2_REN | UART_CR2_RIEN; // Allow RX/TX, generate ints on rx
+}
+
+