Shinichiro Nakamura / Camera_LS_Y201

LinkSprite LS-Y201 JPEG Color Camera.

Dependents:   Camera_LS_Y201_TestProgram Camera_LS_Y201_TestProgram ServoCamV1 RFIDdoor ... more

SerialBuffered.cpp@0:f71232252dcf, 2010-11-25 (annotated)

Committer:
shintamainjp
Date:
Thu Nov 25 15:43:42 2010 +0000
Revision:
0:f71232252dcf
Initial version.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
shintamainjp 0:f71232252dcf 1 /**
shintamainjp 0:f71232252dcf 2 * =============================================================================
shintamainjp 0:f71232252dcf 3 * LS-Y201 device driver class (Version 0.0.1)
shintamainjp 0:f71232252dcf 4 * Reference documents: LinkSprite JPEG Color Camera Serial UART Interface
shintamainjp 0:f71232252dcf 5 * January 2010
shintamainjp 0:f71232252dcf 6 * =============================================================================
shintamainjp 0:f71232252dcf 7 * Copyright (c) 2010 Shinichiro Nakamura (CuBeatSystems)
shintamainjp 0:f71232252dcf 8 *
shintamainjp 0:f71232252dcf 9 * Permission is hereby granted, free of charge, to any person obtaining a copy
shintamainjp 0:f71232252dcf 10 * of this software and associated documentation files (the "Software"), to deal
shintamainjp 0:f71232252dcf 11 * in the Software without restriction, including without limitation the rights
shintamainjp 0:f71232252dcf 12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
shintamainjp 0:f71232252dcf 13 * copies of the Software, and to permit persons to whom the Software is
shintamainjp 0:f71232252dcf 14 * furnished to do so, subject to the following conditions:
shintamainjp 0:f71232252dcf 15 *
shintamainjp 0:f71232252dcf 16 * The above copyright notice and this permission notice shall be included in
shintamainjp 0:f71232252dcf 17 * all copies or substantial portions of the Software.
shintamainjp 0:f71232252dcf 18 *
shintamainjp 0:f71232252dcf 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
shintamainjp 0:f71232252dcf 20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
shintamainjp 0:f71232252dcf 21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
shintamainjp 0:f71232252dcf 22 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
shintamainjp 0:f71232252dcf 23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
shintamainjp 0:f71232252dcf 24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
shintamainjp 0:f71232252dcf 25 * THE SOFTWARE.
shintamainjp 0:f71232252dcf 26 * =============================================================================
shintamainjp 0:f71232252dcf 27 */
shintamainjp 0:f71232252dcf 28
shintamainjp 0:f71232252dcf 29 #include "mbed.h"
shintamainjp 0:f71232252dcf 30 #include "SerialBuffered.h"
shintamainjp 0:f71232252dcf 31
shintamainjp 0:f71232252dcf 32 /**
shintamainjp 0:f71232252dcf 33 * Create a buffered serial class.
shintamainjp 0:f71232252dcf 34 *
shintamainjp 0:f71232252dcf 35 * @param tx A pin for transmit.
shintamainjp 0:f71232252dcf 36 * @param rx A pin for receive.
shintamainjp 0:f71232252dcf 37 */
shintamainjp 0:f71232252dcf 38 SerialBuffered::SerialBuffered(PinName tx, PinName rx) : Serial(tx, rx) {
shintamainjp 0:f71232252dcf 39 indexContentStart = 0;
shintamainjp 0:f71232252dcf 40 indexContentEnd = 0;
shintamainjp 0:f71232252dcf 41 timeout = 1;
shintamainjp 0:f71232252dcf 42 attach(this, &SerialBuffered::handleInterrupt);
shintamainjp 0:f71232252dcf 43 }
shintamainjp 0:f71232252dcf 44
shintamainjp 0:f71232252dcf 45 /**
shintamainjp 0:f71232252dcf 46 * Destroy.
shintamainjp 0:f71232252dcf 47 */
shintamainjp 0:f71232252dcf 48 SerialBuffered::~SerialBuffered() {
shintamainjp 0:f71232252dcf 49 }
shintamainjp 0:f71232252dcf 50
shintamainjp 0:f71232252dcf 51 /**
shintamainjp 0:f71232252dcf 52 * Set timeout for getc().
shintamainjp 0:f71232252dcf 53 *
shintamainjp 0:f71232252dcf 54 * @param ms milliseconds. (-1:Disable timeout)
shintamainjp 0:f71232252dcf 55 */
shintamainjp 0:f71232252dcf 56 void SerialBuffered::setTimeout(int ms) {
shintamainjp 0:f71232252dcf 57 timeout = ms;
shintamainjp 0:f71232252dcf 58 }
shintamainjp 0:f71232252dcf 59
shintamainjp 0:f71232252dcf 60 /**
shintamainjp 0:f71232252dcf 61 * Read requested bytes.
shintamainjp 0:f71232252dcf 62 *
shintamainjp 0:f71232252dcf 63 * @param bytes A pointer to a buffer.
shintamainjp 0:f71232252dcf 64 * @param requested Length.
shintamainjp 0:f71232252dcf 65 *
shintamainjp 0:f71232252dcf 66 * @return Readed byte length.
shintamainjp 0:f71232252dcf 67 */
shintamainjp 0:f71232252dcf 68 size_t SerialBuffered::readBytes(uint8_t *bytes, size_t requested) {
shintamainjp 0:f71232252dcf 69 int i = 0;
shintamainjp 0:f71232252dcf 70 while (i < requested) {
shintamainjp 0:f71232252dcf 71 int c = getc();
shintamainjp 0:f71232252dcf 72 if (c < 0) {
shintamainjp 0:f71232252dcf 73 break;
shintamainjp 0:f71232252dcf 74 }
shintamainjp 0:f71232252dcf 75 bytes[i] = c;
shintamainjp 0:f71232252dcf 76 i++;
shintamainjp 0:f71232252dcf 77 }
shintamainjp 0:f71232252dcf 78 return i;
shintamainjp 0:f71232252dcf 79 }
shintamainjp 0:f71232252dcf 80
shintamainjp 0:f71232252dcf 81 /**
shintamainjp 0:f71232252dcf 82 * Get a character.
shintamainjp 0:f71232252dcf 83 *
shintamainjp 0:f71232252dcf 84 * @return A character. (-1:timeout)
shintamainjp 0:f71232252dcf 85 */
shintamainjp 0:f71232252dcf 86 int SerialBuffered::getc() {
shintamainjp 0:f71232252dcf 87 timer.reset();
shintamainjp 0:f71232252dcf 88 timer.start();
shintamainjp 0:f71232252dcf 89 while (indexContentStart == indexContentEnd) {
shintamainjp 0:f71232252dcf 90 wait_ms(1);
shintamainjp 0:f71232252dcf 91 if ((timeout > 0) && (timer.read_ms() > timeout)) {
shintamainjp 0:f71232252dcf 92 /*
shintamainjp 0:f71232252dcf 93 * Timeout occured.
shintamainjp 0:f71232252dcf 94 */
shintamainjp 0:f71232252dcf 95 // printf("Timeout occured.\n");
shintamainjp 0:f71232252dcf 96 return EOF;
shintamainjp 0:f71232252dcf 97 }
shintamainjp 0:f71232252dcf 98 }
shintamainjp 0:f71232252dcf 99 timer.stop();
shintamainjp 0:f71232252dcf 100
shintamainjp 0:f71232252dcf 101 uint8_t result = buffer[indexContentStart++];
shintamainjp 0:f71232252dcf 102 indexContentStart = indexContentStart % BUFFERSIZE;
shintamainjp 0:f71232252dcf 103
shintamainjp 0:f71232252dcf 104 return result;
shintamainjp 0:f71232252dcf 105 }
shintamainjp 0:f71232252dcf 106
shintamainjp 0:f71232252dcf 107 /**
shintamainjp 0:f71232252dcf 108 * Returns 1 if there is a character available to read, 0 otherwise.
shintamainjp 0:f71232252dcf 109 */
shintamainjp 0:f71232252dcf 110 int SerialBuffered::readable() {
shintamainjp 0:f71232252dcf 111 return indexContentStart != indexContentEnd;
shintamainjp 0:f71232252dcf 112 }
shintamainjp 0:f71232252dcf 113
shintamainjp 0:f71232252dcf 114 void SerialBuffered::handleInterrupt() {
shintamainjp 0:f71232252dcf 115 while (Serial::readable()) {
shintamainjp 0:f71232252dcf 116 if (indexContentStart == ((indexContentEnd + 1) % BUFFERSIZE)) {
shintamainjp 0:f71232252dcf 117 /*
shintamainjp 0:f71232252dcf 118 * Buffer overrun occured.
shintamainjp 0:f71232252dcf 119 */
shintamainjp 0:f71232252dcf 120 // printf("Buffer overrun occured.\n");
shintamainjp 0:f71232252dcf 121 Serial::getc();
shintamainjp 0:f71232252dcf 122 } else {
shintamainjp 0:f71232252dcf 123 buffer[indexContentEnd++] = Serial::getc();
shintamainjp 0:f71232252dcf 124 indexContentEnd = indexContentEnd % BUFFERSIZE;
shintamainjp 0:f71232252dcf 125 }
shintamainjp 0:f71232252dcf 126 }
shintamainjp 0:f71232252dcf 127 }