MicIO.h

00001 /* Mbed MicIO library
00002  * Copyright (c) 2014, Colin Bookman, cobookman [at] gmail [dot] com 
00003  * 
00004  *  This program is free software: you can redistribute it and/or modify
00005  *  it under the terms of the GNU General Public License as published by
00006  *  the Free Software Foundation, either version 3 of the License, or
00007  *  (at your option) any later version.
00008  *
00009  *  This program is distributed in the hope that it will be useful,
00010  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00011  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00012  *  GNU General Public License for more details.
00013  *
00014  *  You should have received a copy of the GNU General Public License
00015  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
00016  */
00017 
00018 #ifndef MBED_MICIO_H
00019 #define MBED_MICIO_H
00020 
00021 #include "mbed.h"
00022 
00023 /**
00024  * @code
00025  * #include "MicIO.h"
00026  * 
00027  * MicIO micIO(p18,p19); //AnalogOut (Output - Mic), AnalogIn (Input Headphone Left/Right)
00028  * 
00029  * int main() {
00030  *     micIO.send("HI WORLD", 8);
00031  *     micIO.send([0xFF, 0xFA, 0xFB, 0x00], 4);
00032  * }
00033  * @endcode
00034  */
00035 class MicIO  {
00036 public:
00037 
00038     /** Create a MicIO instance */
00039     MicIO(PinName output, PinName input);
00040     float clockPeriod;
00041     
00042     /* Send byte array through micIO */
00043     void send(const char * arr, int length);
00044     
00045     /* Send just 4 bits */
00046     void send4Bits(unsigned char byte);
00047     
00048     /*
00049         Read the current value of the input clock.
00050         1 = high
00051         0 = low
00052         -1 = unchanged
00053     */
00054     int clock();
00055     
00056     /* Extracts the lower 4 bits of a byte */
00057     unsigned char lower4Bits(unsigned char byte);
00058     /* Extracts the upper 4 bits of a byte */
00059     unsigned char upper4Bits(unsigned char byte);
00060     
00061 protected:
00062     AnalogOut _micOut;
00063     AnalogIn  _clockIn;
00064     float _sinTable[361]; //361 in case of overflow...not that it SHOULD happen
00065     /*
00066         sendSin outputs a sin wave for 1 period.
00067                 -------------------------
00068                 |Speed  |               |
00069                 |Factor | Frequency     |
00070                 |------------------------
00071                 | 4.75  |   5.73Khz     |
00072                 | 4.50  |   5.45Khz     |
00073                 | 4.25  |   5.13Khz     |
00074                 | 4.00  |   4.84Khz     |
00075                 | 3.75  |   4.54Khz     |
00076                 | 3.50  |   4.23Khz     |
00077                 | 3.25  |   3.92Khz     |
00078                 | 3.00  |   3.65-3.62Khz|
00079                 | 2.75  |   3.33Khz     |
00080                 | 2.50  |   3Khz        |
00081                 | 2.25  |   2.73Khz     |
00082                 | 2.00  |   2.41Khz     |
00083                 | 1.75  |   2.12Khz     |
00084                 | 1.50  |   1.818Khz    |
00085                 | 1.25  |   1.5Khz      |
00086                 | 1.00  |   1.2Khz      |
00087                 | 0.75  |   0.909KHz    |
00088                 | 0.5   |   0.606Khz    |
00089                 -------------------------
00090     */
00091     void _sendSin(float sinSeed); //sinSeed of 1 = 5khz
00092     
00093     /* Get the number of cycles the sin wave should run for */
00094     int _numCycles(float sinSeed);
00095     
00096     /* Generate a sin Table */
00097     void _genSinTable();
00098     
00099      /* Go from 4 bits to a sin seed */
00100     float _getSinSeed(unsigned char bits4);
00101     
00102 };
00103 
00104 #endif