Sam Grove / 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:   buffered_serial_test BLE_Police_HRM evena_BLE_Police_HRM df-2014-workshop-rfid-case-generator-k64f ... more

Example

 #include "mbed.h"
 #include "BufferedSerial.h"

 BufferedSerial pc(USBTX, USBRX);

 int main()
 {
     pc.baud(115200);
   
     while(1)
     {
         Timer s;
       
         s.start();
         pc.printf("Hello World - buff\n");
         int buffered_time = s.read_us();
         wait(0.1f); // give time for the buffer to empty
       
         s.reset();
         printf("Hello World - poll\n");
         int polled_time = s.read_us();
         s.stop();
         wait(0.1f); // give time for the buffer to empty
       
         pc.printf("printf buffered took %d us\n", buffered_time);
         pc.printf("printf polled took %d us\n", polled_time);
         wait(0.5f);
     }
 }

BufferedSerial.h@8:506247a040bc, 2015-01-04 (annotated)

Committer:
ansond
Date:
Sun Jan 04 22:15:53 2015 +0000
Revision:
8:506247a040bc
Parent:
7:6fa214b41d73
Child:
9:2cb30392ade6
increased buffer sizes more

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
ansond 7:6fa214b41d73 30 // Base Class
ansond 6:8287e83943f0 31 #define SERIAL_BASE RawSerial
ansond 6:8287e83943f0 32
ansond 8:506247a040bc 33 // Internal buffer size (Ring buffers will be 2X this value each for RX and TX...)
ansond 8:506247a040bc 34 #define BUFFEREDSERIAL_MAX_BUFFER_SIZE 4096
ansond 7:6fa214b41d73 35
sam_grove 0:a977d0a3d81e 36 /** A serial port (UART) for communication with other serial devices
sam_grove 0:a977d0a3d81e 37 *
sam_grove 0:a977d0a3d81e 38 * Can be used for Full Duplex communication, or Simplex by specifying
sam_grove 0:a977d0a3d81e 39 * one pin as NC (Not Connected)
sam_grove 0:a977d0a3d81e 40 *
sam_grove 0:a977d0a3d81e 41 * Example:
sam_grove 0:a977d0a3d81e 42 * @code
sam_grove 0:a977d0a3d81e 43 * #include "mbed.h"
sam_grove 0:a977d0a3d81e 44 * #include "BufferedSerial.h"
sam_grove 0:a977d0a3d81e 45 *
sam_grove 0:a977d0a3d81e 46 * BufferedSerial pc(USBTX, USBRX);
sam_grove 0:a977d0a3d81e 47 *
sam_grove 0:a977d0a3d81e 48 * int main()
sam_grove 5:4d6a311fc8bf 49 * {
sam_grove 0:a977d0a3d81e 50 * while(1)
sam_grove 0:a977d0a3d81e 51 * {
sam_grove 0:a977d0a3d81e 52 * Timer s;
sam_grove 0:a977d0a3d81e 53 *
sam_grove 0:a977d0a3d81e 54 * s.start();
sam_grove 5:4d6a311fc8bf 55 * pc.printf("Hello World - buffered\n");
sam_grove 0:a977d0a3d81e 56 * int buffered_time = s.read_us();
sam_grove 0:a977d0a3d81e 57 * wait(0.1f); // give time for the buffer to empty
sam_grove 0:a977d0a3d81e 58 *
sam_grove 0:a977d0a3d81e 59 * s.reset();
sam_grove 5:4d6a311fc8bf 60 * printf("Hello World - blocking\n");
sam_grove 0:a977d0a3d81e 61 * int polled_time = s.read_us();
sam_grove 0:a977d0a3d81e 62 * s.stop();
sam_grove 0:a977d0a3d81e 63 * wait(0.1f); // give time for the buffer to empty
sam_grove 0:a977d0a3d81e 64 *
sam_grove 0:a977d0a3d81e 65 * pc.printf("printf buffered took %d us\n", buffered_time);
sam_grove 5:4d6a311fc8bf 66 * pc.printf("printf blocking took %d us\n", polled_time);
sam_grove 0:a977d0a3d81e 67 * wait(0.5f);
sam_grove 0:a977d0a3d81e 68 * }
sam_grove 0:a977d0a3d81e 69 * }
sam_grove 0:a977d0a3d81e 70 * @endcode
sam_grove 0:a977d0a3d81e 71 */
sam_grove 0:a977d0a3d81e 72
sam_grove 0:a977d0a3d81e 73 /**
sam_grove 0:a977d0a3d81e 74 * @class BufferedSerial
sam_grove 0:a977d0a3d81e 75 * @brief Software buffers and interrupt driven tx and rx for Serial
sam_grove 0:a977d0a3d81e 76 */
ansond 6:8287e83943f0 77 class BufferedSerial : public SERIAL_BASE
sam_grove 0:a977d0a3d81e 78 {
sam_grove 0:a977d0a3d81e 79 private:
sam_grove 3:6b76fcf27545 80 Buffer <char> _rxbuf;
sam_grove 3:6b76fcf27545 81 Buffer <char> _txbuf;
ansond 7:6fa214b41d73 82 char _buffer[BUFFEREDSERIAL_MAX_BUFFER_SIZE+1];
sam_grove 0:a977d0a3d81e 83
sam_grove 0:a977d0a3d81e 84 void rxIrq(void);
sam_grove 0:a977d0a3d81e 85 void txIrq(void);
sam_grove 1:57a11fb5d529 86 void prime(void);
sam_grove 0:a977d0a3d81e 87
sam_grove 0:a977d0a3d81e 88 public:
sam_grove 0:a977d0a3d81e 89 /** Create a BufferedSerial port, connected to the specified transmit and receive pins
sam_grove 0:a977d0a3d81e 90 * @param tx Transmit pin
sam_grove 0:a977d0a3d81e 91 * @param rx Receive pin
ansond 7:6fa214b41d73 92 * @param name optional name
sam_grove 0:a977d0a3d81e 93 * @note Either tx or rx may be specified as NC if unused
sam_grove 0:a977d0a3d81e 94 */
sam_grove 0:a977d0a3d81e 95 BufferedSerial(PinName tx, PinName rx, const char* name=NULL);
sam_grove 0:a977d0a3d81e 96
sam_grove 0:a977d0a3d81e 97 /** Destroy a BufferedSerial port
sam_grove 0:a977d0a3d81e 98 */
sam_grove 0:a977d0a3d81e 99 virtual ~BufferedSerial(void);
sam_grove 0:a977d0a3d81e 100
sam_grove 0:a977d0a3d81e 101 /** Check on how many bytes are in the rx buffer
sam_grove 0:a977d0a3d81e 102 * @return 1 if something exists, 0 otherwise
sam_grove 0:a977d0a3d81e 103 */
sam_grove 0:a977d0a3d81e 104 virtual int readable(void);
sam_grove 0:a977d0a3d81e 105
sam_grove 0:a977d0a3d81e 106 /** Check to see if the tx buffer has room
sam_grove 0:a977d0a3d81e 107 * @return 1 always has room and can overwrite previous content if too small / slow
sam_grove 0:a977d0a3d81e 108 */
sam_grove 0:a977d0a3d81e 109 virtual int writeable(void);
sam_grove 0:a977d0a3d81e 110
sam_grove 0:a977d0a3d81e 111 /** Get a single byte from the BufferedSerial Port.
sam_grove 0:a977d0a3d81e 112 * Should check readable() before calling this.
sam_grove 0:a977d0a3d81e 113 * @return A byte that came in on the Serial Port
sam_grove 0:a977d0a3d81e 114 */
sam_grove 0:a977d0a3d81e 115 virtual int getc(void);
sam_grove 0:a977d0a3d81e 116
sam_grove 0:a977d0a3d81e 117 /** Write a single byte to the BufferedSerial Port.
sam_grove 0:a977d0a3d81e 118 * @param c The byte to write to the Serial Port
sam_grove 2:7e8a450a9101 119 * @return The byte that was written to the Serial Port Buffer
sam_grove 0:a977d0a3d81e 120 */
sam_grove 0:a977d0a3d81e 121 virtual int putc(int c);
sam_grove 0:a977d0a3d81e 122
sam_grove 0:a977d0a3d81e 123 /** Write a string to the BufferedSerial Port. Must be NULL terminated
sam_grove 0:a977d0a3d81e 124 * @param s The string to write to the Serial Port
sam_grove 2:7e8a450a9101 125 * @return The number of bytes written to the Serial Port Buffer
sam_grove 0:a977d0a3d81e 126 */
sam_grove 0:a977d0a3d81e 127 virtual int puts(const char *s);
sam_grove 0:a977d0a3d81e 128
sam_grove 0:a977d0a3d81e 129 /** Write a formatted string to the BufferedSerial Port.
sam_grove 0:a977d0a3d81e 130 * @param format The string + format specifiers to write to the Serial Port
sam_grove 2:7e8a450a9101 131 * @return The number of bytes written to the Serial Port Buffer
sam_grove 0:a977d0a3d81e 132 */
sam_grove 0:a977d0a3d81e 133 virtual int printf(const char* format, ...);
sam_grove 0:a977d0a3d81e 134
sam_grove 2:7e8a450a9101 135 /** Write data to the Buffered Serial Port
sam_grove 2:7e8a450a9101 136 * @param s A pointer to data to send
sam_grove 2:7e8a450a9101 137 * @param length The amount of data being pointed to
sam_grove 2:7e8a450a9101 138 * @return The number of bytes written to the Serial Port Buffer
sam_grove 2:7e8a450a9101 139 */
sam_grove 2:7e8a450a9101 140 virtual ssize_t write(const void *s, std::size_t length);
sam_grove 0:a977d0a3d81e 141 };
sam_grove 0:a977d0a3d81e 142
sam_grove 0:a977d0a3d81e 143 #endif