Yann Garcia / SignalGenerator

This library provides a class to generate differents signale wave form. Note that the maximum update rate of 1 MHz, so Fmax = 1MHz / _num_pixels (see UM10360 - Chapter 30: LPC17xx Digital-to-Analog Converter (DAC).

SignalGenerator.cpp@1:d6cbee8595e0, 2010-11-22 (annotated)

Committer:
Yann
Date:
Mon Nov 22 08:14:22 2010 +0000
Revision:
1:d6cbee8595e0
Parent:
0:40051400cafe 
V0.0.2

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Yann 0:40051400cafe 1 #include "SignalGenerator.h"
Yann 0:40051400cafe 2
Yann 0:40051400cafe 3 #define PI 3.1415
Yann 0:40051400cafe 4
Yann 0:40051400cafe 5 SignalGenerator::SignalGenerator(PinName p_outPort) : _out(p_outPort), _asyncTicker(), _debugLed(LED4) {
Yann 0:40051400cafe 6 _debugLed = 0;
Yann 0:40051400cafe 7 _mode = true; // _num_pixels is fixed, _twait is computed
Yann 0:40051400cafe 8 _stop = false;
Yann 0:40051400cafe 9 _values = NULL;
Yann 0:40051400cafe 10 SetSignalFrequency();
Yann 0:40051400cafe 11 } // End of SignalGenerator::SignalGenerator
Yann 0:40051400cafe 12
Yann 0:40051400cafe 13 SignalGenerator::~SignalGenerator() {
Yann 0:40051400cafe 14 if (_values != NULL) {
Yann 0:40051400cafe 15 delete [] _values;
Yann 0:40051400cafe 16 }
Yann 0:40051400cafe 17 } // End of SignalGenerator::~SignalGenerator
Yann 0:40051400cafe 18
Yann 0:40051400cafe 19 void SignalGenerator::SetSignalFrequency(SignalGenerator::SignalGeneratorType p_signalType, int p_frequency, int p_num_pixels) {
Yann 0:40051400cafe 20 DEBUG_ENTER("SignalGenerator::SetSignalFrequency")
Yann 0:40051400cafe 21 if (_values != NULL) {
Yann 0:40051400cafe 22 DEBUG("SignalGenerator::SetSignalFrequency: Delete _values");
Yann 0:40051400cafe 23 delete [] _values;
Yann 0:40051400cafe 24 }
Yann 0:40051400cafe 25
Yann 0:40051400cafe 26 _signalType = p_signalType;
Yann 0:40051400cafe 27 _frequency = p_frequency;
Yann 0:40051400cafe 28 _num_pixels = p_num_pixels;
Yann 1:d6cbee8595e0 29 DEBUG("SignalGenerator::SetSignalFrequency: _frequency=%d", _frequency)
Yann 0:40051400cafe 30 if (_mode) {
Yann 0:40051400cafe 31 //_twait = 1000000.0f / (_frequency * _num_pixels); // _num_pixels is set to 1000 pixels/T
Yann 0:40051400cafe 32 _twait = 1.0f / (_frequency * _num_pixels); // _num_pixels is set to 1000 pixels/T
Yann 0:40051400cafe 33 } else {
Yann 0:40051400cafe 34 _twait = 0.000001f; // 1us
Yann 0:40051400cafe 35 _num_pixels = (int)(1.0f / (_frequency * _twait)); // t_w is set to 1us and we fix at least 1000 pixels per period (T >> t_w): T >= 1000 * t_w ==> F < 1KHz
Yann 0:40051400cafe 36 }
Yann 1:d6cbee8595e0 37 DEBUG("SignalGenerator::SetSignalFrequency: _twait=%f", _twait)
Yann 1:d6cbee8595e0 38 DEBUG("SignalGenerator::SetSignalFrequency: _num_pixels=%d", _num_pixels)
Yann 0:40051400cafe 39 _values = new float[_num_pixels];
Yann 0:40051400cafe 40 PrepareSignal();
Yann 0:40051400cafe 41 DEBUG_LEAVE("SignalGenerator::SetSignalFrequency")
Yann 0:40051400cafe 42 } // End of SignalGenerator::SetSignalFrequency
Yann 0:40051400cafe 43
Yann 0:40051400cafe 44 void SignalGenerator::PrepareSignal() {
Yann 0:40051400cafe 45 switch (_signalType) {
Yann 0:40051400cafe 46 case SquareSignal:
Yann 0:40051400cafe 47 PrepareSquareSignal();
Yann 0:40051400cafe 48 break;
Yann 0:40051400cafe 49 case TriangleSignal:
Yann 0:40051400cafe 50 PrepareTriangleSignal();
Yann 0:40051400cafe 51 break;
Yann 0:40051400cafe 52 case SawtoothSignal:
Yann 0:40051400cafe 53 PrepareSawtoothSignal();
Yann 0:40051400cafe 54 break;
Yann 0:40051400cafe 55 case ReverseSawtoothSignal:
Yann 0:40051400cafe 56 PrepareReverseSawtoothSignal();
Yann 0:40051400cafe 57 break;
Yann 0:40051400cafe 58 case SinusSignal:
Yann 0:40051400cafe 59 PrepareSinusSignal();
Yann 0:40051400cafe 60 break;
Yann 0:40051400cafe 61 } // End of 'switch' statement
Yann 0:40051400cafe 62 } // End of SignalGenerator::PrepareSignal
Yann 0:40051400cafe 63
Yann 0:40051400cafe 64 void SignalGenerator::Run() {
Yann 0:40051400cafe 65 DEBUG_ENTER("SignalGenerator::Run")
Yann 0:40051400cafe 66 do {
Yann 0:40051400cafe 67 for (int i = 0; i < _num_pixels; i++) {
Yann 0:40051400cafe 68 _out = *(_values + i);
Yann 0:40051400cafe 69 //DEBUG_1f("SignalGenerator::Run: Current=", (float)_out)
Yann 0:40051400cafe 70 wait(_twait);
Yann 0:40051400cafe 71 }
Yann 0:40051400cafe 72 } while (!_stop);
Yann 0:40051400cafe 73 _out = 0.0f; // Reset output
Yann 0:40051400cafe 74 DEBUG_LEAVE("SignalGenerator::Run")
Yann 0:40051400cafe 75 } // End of SignalGenerator::Run
Yann 0:40051400cafe 76
Yann 0:40051400cafe 77 void SignalGenerator::Stop() {
Yann 0:40051400cafe 78 DEBUG_ENTER("SignalGenerator::Stop")
Yann 0:40051400cafe 79 _stop = true;
Yann 0:40051400cafe 80 DEBUG_LEAVE("SignalGenerator::Stop")
Yann 0:40051400cafe 81 } // End of SignalGenerator::Stop
Yann 0:40051400cafe 82
Yann 0:40051400cafe 83 int SignalGenerator::BeginRunAsync() {
Yann 0:40051400cafe 84 DEBUG_ENTER("SignalGenerator::BeginRunAsync")
Yann 0:40051400cafe 85 if (_twait < 0.000007f) {
Yann 0:40051400cafe 86 return -1;
Yann 0:40051400cafe 87 } else {
Yann 0:40051400cafe 88 _asynckCounter = 0;
Yann 0:40051400cafe 89 _asyncTicker.attach(this, &SignalGenerator::RunAsync, _twait);
Yann 0:40051400cafe 90 }
Yann 0:40051400cafe 91 DEBUG_LEAVE("SignalGenerator::BeginRunAsync")
Yann 0:40051400cafe 92 return 0;
Yann 0:40051400cafe 93 } // End of SignalGenerator::BeginRunAsync
Yann 0:40051400cafe 94
Yann 0:40051400cafe 95 void SignalGenerator::RunAsync() {
Yann 0:40051400cafe 96 //DEBUG_ENTER("SignalGenerator::RunAsync")
Yann 0:40051400cafe 97 _debugLed = !_debugLed;
Yann 0:40051400cafe 98 _out = *(_values + _asynckCounter++);
Yann 0:40051400cafe 99 _asynckCounter %= _num_pixels;
Yann 0:40051400cafe 100 //DEBUG_LEAVE("SignalGenerator::RunAsync")
Yann 0:40051400cafe 101 } // End of SignalGenerator::RunAsync
Yann 0:40051400cafe 102
Yann 0:40051400cafe 103 void SignalGenerator::EndRunAsync() {
Yann 0:40051400cafe 104 DEBUG_ENTER("SignalGenerator::EndRunAsync")
Yann 0:40051400cafe 105 _asyncTicker.detach();
Yann 0:40051400cafe 106 _out = 0.0f; // Reset output
Yann 0:40051400cafe 107 DEBUG_LEAVE("SignalGenerator::EndRunAsync")
Yann 0:40051400cafe 108 } // End of SignalGenerator::EndRunAsync
Yann 0:40051400cafe 109
Yann 0:40051400cafe 110 SignalGenerator& SignalGenerator::operator =(const int& p_frequency) {
Yann 0:40051400cafe 111 DEBUG_ENTER("SignalGenerator::operator =")
Yann 0:40051400cafe 112 if (_frequency != p_frequency) {
Yann 0:40051400cafe 113 this->SetSignalFrequency(_signalType, p_frequency);
Yann 0:40051400cafe 114 }
Yann 0:40051400cafe 115 DEBUG_LEAVE("SignalGenerator::operator =")
Yann 0:40051400cafe 116 return *this;
Yann 0:40051400cafe 117 } // End of SignalGenerator::operator =
Yann 0:40051400cafe 118
Yann 0:40051400cafe 119 SignalGenerator& SignalGenerator::operator =(const bool& p_mode) {
Yann 0:40051400cafe 120 DEBUG_ENTER("SignalGenerator::operator =")
Yann 0:40051400cafe 121 if (_mode != p_mode) {
Yann 0:40051400cafe 122 _mode = p_mode;
Yann 0:40051400cafe 123 this->SetSignalFrequency(_signalType, _frequency);
Yann 0:40051400cafe 124 }
Yann 0:40051400cafe 125 DEBUG_LEAVE("SignalGenerator::operator =")
Yann 0:40051400cafe 126 return *this;
Yann 0:40051400cafe 127 } // End of SignalGenerator::operator =
Yann 0:40051400cafe 128
Yann 0:40051400cafe 129 SignalGenerator& SignalGenerator::operator =(const SignalGenerator::SignalGeneratorType& p_signalType) {
Yann 0:40051400cafe 130 DEBUG_ENTER("SignalGenerator::operator =")
Yann 0:40051400cafe 131 this->SetSignalFrequency(p_signalType, _frequency);
Yann 0:40051400cafe 132 DEBUG_LEAVE("SignalGenerator::operator =")
Yann 0:40051400cafe 133 return *this;
Yann 0:40051400cafe 134
Yann 0:40051400cafe 135 } // End of SignalGenerator::operator =
Yann 0:40051400cafe 136
Yann 0:40051400cafe 137 void SignalGenerator::PrepareSquareSignal() {
Yann 0:40051400cafe 138 DEBUG_ENTER("SignalGenerator::PrepareSquareSignal")
Yann 0:40051400cafe 139 int step = _num_pixels / 2;
Yann 0:40051400cafe 140 for (int i = 0; i < step; i += 1) {
Yann 0:40051400cafe 141 *(_values + i) = 1.0f;
Yann 0:40051400cafe 142 } // End of 'for' statement
Yann 0:40051400cafe 143 for (int i = step; i < _num_pixels; i += 1) {
Yann 0:40051400cafe 144 *(_values + i) = 0.0f;
Yann 0:40051400cafe 145 } // End of 'for' statement
Yann 0:40051400cafe 146 DEBUG_ENTER("SignalGenerator::PrepareSquareSignal")
Yann 0:40051400cafe 147 } // End of SignalGenerator::PrepareSquareSignal
Yann 0:40051400cafe 148
Yann 0:40051400cafe 149 void SignalGenerator::PrepareTriangleSignal() {
Yann 0:40051400cafe 150 float step = 1.0f / (_num_pixels / 2.0f);
Yann 0:40051400cafe 151 int counter = 0;
Yann 0:40051400cafe 152 float i = 0.0f;
Yann 0:40051400cafe 153 for ( ; i < 1.0f; i += step) {
Yann 0:40051400cafe 154 *(_values + counter++) = i;
Yann 0:40051400cafe 155 } // End of 'for' statement
Yann 0:40051400cafe 156 for ( ; i >= 0.0f; i -= step) {
Yann 0:40051400cafe 157 *(_values + counter++) = i;
Yann 0:40051400cafe 158 } // End of 'for' statement
Yann 0:40051400cafe 159 } // End of SignalGenerator::PrepareTriangleSignal
Yann 0:40051400cafe 160
Yann 0:40051400cafe 161 void SignalGenerator::PrepareSawtoothSignal() {
Yann 0:40051400cafe 162 float step = 1.0f / _num_pixels;
Yann 0:40051400cafe 163 int counter = 0;
Yann 0:40051400cafe 164 for (float i = 0.0f; i < 1.0f; i += step) {
Yann 0:40051400cafe 165 *(_values + counter++) = i;
Yann 0:40051400cafe 166 } // End of 'for' statement
Yann 0:40051400cafe 167 } // End of SignalGenerator::PrepareSawtoothSignal
Yann 0:40051400cafe 168
Yann 0:40051400cafe 169 void SignalGenerator::PrepareReverseSawtoothSignal() {
Yann 0:40051400cafe 170 float step = 1.0f / _num_pixels;
Yann 0:40051400cafe 171 int counter = 0;
Yann 0:40051400cafe 172 for (float i = 0.0f; i < 1.0f; i += step) {
Yann 0:40051400cafe 173 *(_values + counter++) = (1.0f - i);
Yann 0:40051400cafe 174 } // End of 'for' statement
Yann 0:40051400cafe 175 } // End of SignalGenerator::PrepareReverseSawtoothSignal
Yann 0:40051400cafe 176
Yann 0:40051400cafe 177 void SignalGenerator::PrepareSinusSignal() {
Yann 0:40051400cafe 178 float step = 1.0f / _num_pixels;
Yann 0:40051400cafe 179 int counter = 0;
Yann 0:40051400cafe 180 for (float i = 0.0f; i < 1.0f; i += step) {
Yann 0:40051400cafe 181 *(_values + counter++) = sin(2 * PI * i);
Yann 0:40051400cafe 182 } // End of 'for' statement
Yann 0:40051400cafe 183 } // End of SignalGenerator::PrepareSinusSignal