2 Copyright 2012 Jun WAKO <wakojun@gmail.com>
4 This software is licensed with a Modified BSD License.
5 All of this is supposed to be Free Software, Open Source, DFSG-free,
6 GPL-compatible, and OK to use in both free and proprietary applications.
7 Additions and corrections to this file are welcome.
10 Redistribution and use in source and binary forms, with or without
11 modification, are permitted provided that the following conditions are met:
13 * Redistributions of source code must retain the above copyright
14 notice, this list of conditions and the following disclaimer.
16 * Redistributions in binary form must reproduce the above copyright
17 notice, this list of conditions and the following disclaimer in
18 the documentation and/or other materials provided with the
21 * Neither the name of the copyright holders nor the names of
22 contributors may be used to endorse or promote products derived
23 from this software without specific prior written permission.
25 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
29 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 POSSIBILITY OF SUCH DAMAGE.
40 #include <avr/interrupt.h>
41 #include <util/delay.h>
45 * Stupid Inefficient Busy-wait Software Serial
46 * which is still useful for negative logic signal like Sun protocol
47 * if it is not supported by hardware UART.
49 * TODO: delay is not accurate enough. Instruction cycle should be counted and inline assemby is needed.
52 #define WAIT_US (1000000L/SERIAL_SOFT_BAUD)
54 #ifdef SERIAL_SOFT_LOGIC_NEGATIVE
55 #define SERIAL_SOFT_RXD_IN() !(SERIAL_SOFT_RXD_READ())
56 #define SERIAL_SOFT_TXD_ON() SERIAL_SOFT_TXD_LO()
57 #define SERIAL_SOFT_TXD_OFF() SERIAL_SOFT_TXD_HI()
59 #define SERIAL_SOFT_RXD_IN() !!(SERIAL_SOFT_RXD_READ())
60 #define SERIAL_SOFT_TXD_ON() SERIAL_SOFT_TXD_HI()
61 #define SERIAL_SOFT_TXD_OFF() SERIAL_SOFT_TXD_LO()
64 #ifdef SERIAL_SOFT_PARITY_EVEN
65 #define SERIAL_SOFT_PARITY_VAL 0
66 #elif defined(SERIAL_SOFT_PARITY_ODD)
67 #define SERIAL_SOFT_PARITY_VAL 1
70 /* debug for signal timing, see debug pin with oscilloscope */
71 #ifdef SERIAL_SOFT_DEBUG
72 #define SERIAL_SOFT_DEBUG_INIT() (DDRD |= 1<<7)
73 #define SERIAL_SOFT_DEBUG_TGL() (PORTD ^= 1<<7)
75 #define SERIAL_SOFT_DEBUG_INIT()
76 #define SERIAL_SOFT_DEBUG_TGL()
80 void serial_init(void)
82 SERIAL_SOFT_DEBUG_INIT();
84 SERIAL_SOFT_RXD_INIT();
85 SERIAL_SOFT_TXD_INIT();
90 static uint8_t rbuf[RBUF_SIZE];
91 static uint8_t rbuf_head = 0;
92 static uint8_t rbuf_tail = 0;
95 uint8_t serial_recv(void)
98 if (rbuf_head == rbuf_tail) {
102 data = rbuf[rbuf_tail];
103 rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
107 int16_t serial_recv2(void)
110 if (rbuf_head == rbuf_tail) {
114 data = rbuf[rbuf_tail];
115 rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
119 void serial_send(uint8_t data)
121 /* signal state: IDLE: ON, START: OFF, STOP: ON, DATA0: OFF, DATA1: ON */
123 #ifdef SERIAL_SOFT_BIT_ORDER_MSB
124 #ifdef SERIAL_SOFT_DATA_7BIT
136 SERIAL_SOFT_TXD_OFF();
139 #ifdef SERIAL_SOFT_DATA_7BIT
145 SERIAL_SOFT_TXD_ON();
148 SERIAL_SOFT_TXD_OFF();
152 #ifdef SERIAL_SOFT_BIT_ORDER_MSB
159 #if defined(SERIAL_SOFT_PARITY_EVEN) || defined(SERIAL_SOFT_PARITY_ODD)
160 /* to center of parity bit */
161 if (parity != SERIAL_SOFT_PARITY_VAL) {
162 SERIAL_SOFT_TXD_ON();
164 SERIAL_SOFT_TXD_OFF();
170 SERIAL_SOFT_TXD_ON();
174 /* detect edge of start bit */
175 ISR(SERIAL_SOFT_RXD_VECT)
177 SERIAL_SOFT_DEBUG_TGL();
178 SERIAL_SOFT_RXD_INT_ENTER();
182 #ifdef SERIAL_SOFT_BIT_ORDER_MSB
183 #ifdef SERIAL_SOFT_DATA_7BIT
194 /* to center of start bit */
195 _delay_us(WAIT_US/2);
196 SERIAL_SOFT_DEBUG_TGL();
198 /* to center of next bit */
201 SERIAL_SOFT_DEBUG_TGL();
202 if (SERIAL_SOFT_RXD_IN()) {
206 #ifdef SERIAL_SOFT_BIT_ORDER_MSB
211 #ifdef SERIAL_SOFT_DATA_7BIT
217 #if defined(SERIAL_SOFT_PARITY_EVEN) || defined(SERIAL_SOFT_PARITY_ODD)
218 /* to center of parity bit */
220 if (SERIAL_SOFT_RXD_IN()) { parity ^= 1; }
221 SERIAL_SOFT_DEBUG_TGL();
224 /* to center of stop bit */
227 uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
228 #if defined(SERIAL_SOFT_PARITY_EVEN) || defined(SERIAL_SOFT_PARITY_ODD)
229 if ((parity == SERIAL_SOFT_PARITY_VAL) && next != rbuf_tail) {
231 if (next != rbuf_tail) {
233 rbuf[rbuf_head] = data;
237 SERIAL_SOFT_RXD_INT_EXIT();
238 SERIAL_SOFT_DEBUG_TGL();