Diff: mylib/Camera_LS_Y201/SerialBuffered.cpp

Revision:

0:d69efd0ee139

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mylib/Camera_LS_Y201/SerialBuffered.cpp	Thu Sep 18 15:21:47 2014 +0000
@@ -0,0 +1,127 @@
+/**
+ * =============================================================================
+ * LS-Y201 device driver class (Version 0.0.1)
+ * Reference documents: LinkSprite JPEG Color Camera Serial UART Interface
+ *                      January 2010
+ * =============================================================================
+ * Copyright (c) 2010 Shinichiro Nakamura (CuBeatSystems)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ * =============================================================================
+ */
+
+#include "mbed.h"
+#include "SerialBuffered.h"
+
+/**
+ * Create a buffered serial class.
+ *
+ * @param tx A pin for transmit.
+ * @param rx A pin for receive.
+ */
+SerialBuffered::SerialBuffered(PinName tx, PinName rx) : Serial(tx, rx) {
+    indexContentStart = 0;
+    indexContentEnd = 0;
+    timeout = 1;
+    attach(this, &SerialBuffered::handleInterrupt);
+}
+
+/**
+ * Destroy.
+ */
+SerialBuffered::~SerialBuffered() {
+}
+
+/**
+ * Set timeout for getc().
+ *
+ * @param ms milliseconds. (-1:Disable timeout)
+ */
+void SerialBuffered::setTimeout(int ms) {
+    timeout = ms;
+}
+
+/**
+ * Read requested bytes.
+ *
+ * @param bytes A pointer to a buffer.
+ * @param requested Length.
+ *
+ * @return Readed byte length.
+ */
+size_t SerialBuffered::readBytes(uint8_t *bytes, size_t requested) {
+    int i = 0;
+    while (i < requested) {
+        int c = getc();
+        if (c < 0) {
+            break;
+        }
+        bytes[i] = c;
+        i++;
+    }
+    return i;
+}
+
+/**
+ * Get a character.
+ *
+ * @return A character. (-1:timeout)
+ */
+int SerialBuffered::getc() {
+    timer.reset();
+    timer.start();
+    while (indexContentStart == indexContentEnd) {
+        wait_ms(1);
+        if ((timeout > 0) && (timer.read_ms() > timeout)) {
+            /*
+             * Timeout occured.
+             */
+            // printf("Timeout occured.\n");
+            return EOF;
+        }
+    }
+    timer.stop();
+
+    uint8_t result = buffer[indexContentStart++];
+    indexContentStart =  indexContentStart % BUFFERSIZE;
+
+    return result;
+}
+
+/**
+ * Returns 1 if there is a character available to read, 0 otherwise.
+ */
+int SerialBuffered::readable() {
+    return indexContentStart != indexContentEnd;
+}
+
+void SerialBuffered::handleInterrupt() {
+    while (Serial::readable()) {
+        if (indexContentStart == ((indexContentEnd + 1) % BUFFERSIZE)) {
+            /*
+             * Buffer overrun occured.
+             */
+            // printf("Buffer overrun occured.\n");
+            Serial::getc();
+        } else {
+            buffer[indexContentEnd++] = Serial::getc();
+            indexContentEnd = indexContentEnd % BUFFERSIZE;
+        }
+    }
+}