steeven lee / BufferedSerial

Inherit from Serial and use software buffers for TX and RX. This allows the UART peripherals to operate in a IRQ driven mode. Overrides most (but not all) stdio functions as Serial did

Dependencies:   Buffer

Dependents:   mbed_esp8266_demo

Fork of BufferedSerial by Sam Grove

BufferedSerial.h@0:a977d0a3d81e, 2013-05-23 (annotated)

Committer:
sam_grove
Date:
Thu May 23 19:31:30 2013 +0000
Revision:
0:a977d0a3d81e
Child:
1:57a11fb5d529
TX and RX peripheral functions are IRQ driven. Most stdlib functions are overridden for transmit. Not so much for reading. getc is implemented but not the more formatted scanf.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sam_grove 0:a977d0a3d81e 1
sam_grove 0:a977d0a3d81e 2 /**
sam_grove 0:a977d0a3d81e 3 * @file BufferedSerial.h
sam_grove 0:a977d0a3d81e 4 * @brief Software Buffer - Extends mbed Serial functionallity adding irq driven TX and RX
sam_grove 0:a977d0a3d81e 5 * @author sam grove
sam_grove 0:a977d0a3d81e 6 * @version 1.0
sam_grove 0:a977d0a3d81e 7 * @see
sam_grove 0:a977d0a3d81e 8 *
sam_grove 0:a977d0a3d81e 9 * Copyright (c) 2013
sam_grove 0:a977d0a3d81e 10 *
sam_grove 0:a977d0a3d81e 11 * Licensed under the Apache License, Version 2.0 (the "License");
sam_grove 0:a977d0a3d81e 12 * you may not use this file except in compliance with the License.
sam_grove 0:a977d0a3d81e 13 * You may obtain a copy of the License at
sam_grove 0:a977d0a3d81e 14 *
sam_grove 0:a977d0a3d81e 15 * http://www.apache.org/licenses/LICENSE-2.0
sam_grove 0:a977d0a3d81e 16 *
sam_grove 0:a977d0a3d81e 17 * Unless required by applicable law or agreed to in writing, software
sam_grove 0:a977d0a3d81e 18 * distributed under the License is distributed on an "AS IS" BASIS,
sam_grove 0:a977d0a3d81e 19 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
sam_grove 0:a977d0a3d81e 20 * See the License for the specific language governing permissions and
sam_grove 0:a977d0a3d81e 21 * limitations under the License.
sam_grove 0:a977d0a3d81e 22 */
sam_grove 0:a977d0a3d81e 23
sam_grove 0:a977d0a3d81e 24 #ifndef BUFFEREDSERIAL_H
sam_grove 0:a977d0a3d81e 25 #define BUFFEREDSERIAL_H
sam_grove 0:a977d0a3d81e 26
sam_grove 0:a977d0a3d81e 27 #include "mbed.h"
sam_grove 0:a977d0a3d81e 28 #include "Buffer.h"
sam_grove 0:a977d0a3d81e 29
sam_grove 0:a977d0a3d81e 30 /** A serial port (UART) for communication with other serial devices
sam_grove 0:a977d0a3d81e 31 *
sam_grove 0:a977d0a3d81e 32 * Can be used for Full Duplex communication, or Simplex by specifying
sam_grove 0:a977d0a3d81e 33 * one pin as NC (Not Connected)
sam_grove 0:a977d0a3d81e 34 *
sam_grove 0:a977d0a3d81e 35 * Example:
sam_grove 0:a977d0a3d81e 36 * @code
sam_grove 0:a977d0a3d81e 37 * #include "mbed.h"
sam_grove 0:a977d0a3d81e 38 * #include "BufferedSerial.h"
sam_grove 0:a977d0a3d81e 39 *
sam_grove 0:a977d0a3d81e 40 * BufferedSerial pc(USBTX, USBRX);
sam_grove 0:a977d0a3d81e 41 *
sam_grove 0:a977d0a3d81e 42 * int main()
sam_grove 0:a977d0a3d81e 43 * {
sam_grove 0:a977d0a3d81e 44 * pc.baud(115200);
sam_grove 0:a977d0a3d81e 45 *
sam_grove 0:a977d0a3d81e 46 * while(1)
sam_grove 0:a977d0a3d81e 47 * {
sam_grove 0:a977d0a3d81e 48 * Timer s;
sam_grove 0:a977d0a3d81e 49 *
sam_grove 0:a977d0a3d81e 50 * s.start();
sam_grove 0:a977d0a3d81e 51 * pc.printf("Hello World - buff\n");
sam_grove 0:a977d0a3d81e 52 * int buffered_time = s.read_us();
sam_grove 0:a977d0a3d81e 53 * wait(0.1f); // give time for the buffer to empty
sam_grove 0:a977d0a3d81e 54 *
sam_grove 0:a977d0a3d81e 55 * s.reset();
sam_grove 0:a977d0a3d81e 56 * printf("Hello World - poll\n");
sam_grove 0:a977d0a3d81e 57 * int polled_time = s.read_us();
sam_grove 0:a977d0a3d81e 58 * s.stop();
sam_grove 0:a977d0a3d81e 59 * wait(0.1f); // give time for the buffer to empty
sam_grove 0:a977d0a3d81e 60 *
sam_grove 0:a977d0a3d81e 61 * pc.printf("printf buffered took %d us\n", buffered_time);
sam_grove 0:a977d0a3d81e 62 * pc.printf("printf polled took %d us\n", polled_time);
sam_grove 0:a977d0a3d81e 63 * wait(0.5f);
sam_grove 0:a977d0a3d81e 64 * }
sam_grove 0:a977d0a3d81e 65 * }
sam_grove 0:a977d0a3d81e 66 * @endcode
sam_grove 0:a977d0a3d81e 67 */
sam_grove 0:a977d0a3d81e 68
sam_grove 0:a977d0a3d81e 69 /**
sam_grove 0:a977d0a3d81e 70 * @class BufferedSerial
sam_grove 0:a977d0a3d81e 71 * @brief Software buffers and interrupt driven tx and rx for Serial
sam_grove 0:a977d0a3d81e 72 */
sam_grove 0:a977d0a3d81e 73 class BufferedSerial : public Serial
sam_grove 0:a977d0a3d81e 74 {
sam_grove 0:a977d0a3d81e 75 private:
sam_grove 0:a977d0a3d81e 76 Buffer <char> _rxbuf;
sam_grove 0:a977d0a3d81e 77 Buffer <char> _txbuf;
sam_grove 0:a977d0a3d81e 78
sam_grove 0:a977d0a3d81e 79 void rxIrq(void);
sam_grove 0:a977d0a3d81e 80 void txIrq(void);
sam_grove 0:a977d0a3d81e 81
sam_grove 0:a977d0a3d81e 82 public:
sam_grove 0:a977d0a3d81e 83 /** Create a BufferedSerial port, connected to the specified transmit and receive pins
sam_grove 0:a977d0a3d81e 84 * @param tx Transmit pin
sam_grove 0:a977d0a3d81e 85 * @param rx Receive pin
sam_grove 0:a977d0a3d81e 86 * @note Either tx or rx may be specified as NC if unused
sam_grove 0:a977d0a3d81e 87 */
sam_grove 0:a977d0a3d81e 88 BufferedSerial(PinName tx, PinName rx, const char* name=NULL);
sam_grove 0:a977d0a3d81e 89
sam_grove 0:a977d0a3d81e 90 /** Destroy a BufferedSerial port
sam_grove 0:a977d0a3d81e 91 */
sam_grove 0:a977d0a3d81e 92 virtual ~BufferedSerial(void);
sam_grove 0:a977d0a3d81e 93
sam_grove 0:a977d0a3d81e 94 /** Check on how many bytes are in the rx buffer
sam_grove 0:a977d0a3d81e 95 * @return 1 if something exists, 0 otherwise
sam_grove 0:a977d0a3d81e 96 */
sam_grove 0:a977d0a3d81e 97 virtual int readable(void);
sam_grove 0:a977d0a3d81e 98
sam_grove 0:a977d0a3d81e 99 /** Check to see if the tx buffer has room
sam_grove 0:a977d0a3d81e 100 * @return 1 always has room and can overwrite previous content if too small / slow
sam_grove 0:a977d0a3d81e 101 */
sam_grove 0:a977d0a3d81e 102 virtual int writeable(void);
sam_grove 0:a977d0a3d81e 103
sam_grove 0:a977d0a3d81e 104 /** Get a single byte from the BufferedSerial Port.
sam_grove 0:a977d0a3d81e 105 * Should check readable() before calling this.
sam_grove 0:a977d0a3d81e 106 * @return A byte that came in on the Serial Port
sam_grove 0:a977d0a3d81e 107 */
sam_grove 0:a977d0a3d81e 108 virtual int getc(void);
sam_grove 0:a977d0a3d81e 109
sam_grove 0:a977d0a3d81e 110 /** Write a single byte to the BufferedSerial Port.
sam_grove 0:a977d0a3d81e 111 * @param c The byte to write to the Serial Port
sam_grove 0:a977d0a3d81e 112 * @return The byte that was written to the Serial Port
sam_grove 0:a977d0a3d81e 113 */
sam_grove 0:a977d0a3d81e 114 virtual int putc(int c);
sam_grove 0:a977d0a3d81e 115
sam_grove 0:a977d0a3d81e 116 /** Write a string to the BufferedSerial Port. Must be NULL terminated
sam_grove 0:a977d0a3d81e 117 * @param s The string to write to the Serial Port
sam_grove 0:a977d0a3d81e 118 * @return The number of bytes written to the Serial Port
sam_grove 0:a977d0a3d81e 119 */
sam_grove 0:a977d0a3d81e 120 virtual int puts(const char *s);
sam_grove 0:a977d0a3d81e 121
sam_grove 0:a977d0a3d81e 122 /** Write a formatted string to the BufferedSerial Port.
sam_grove 0:a977d0a3d81e 123 * @param format The string + format specifiers to write to the Serial Port
sam_grove 0:a977d0a3d81e 124 * @return The number of bytes written to the Serial Port
sam_grove 0:a977d0a3d81e 125 */
sam_grove 0:a977d0a3d81e 126 virtual int printf(const char* format, ...);
sam_grove 0:a977d0a3d81e 127
sam_grove 0:a977d0a3d81e 128 };
sam_grove 0:a977d0a3d81e 129
sam_grove 0:a977d0a3d81e 130 #endif