David Smart / Mbed 2 deprecated SignalGenerator

Signal Generator

Dependencies:   IniManager RA8875 Watchdog mbed-rtos mbed

Fork of speaker_demo_Analog by jim hamblen

SignalGenDAC.cpp@4:10281ddb673d, 2017-01-16 (annotated)

Committer:
WiredHome
Date:
Mon Jan 16 21:05:13 2017 +0000
Revision:
4:10281ddb673d
Parent:
3:d22f3e52d06a
Child:
5:49dd0c647a40
Basic functions (excluding frequency) are working. Waveform, amplitude, offset, start/stop.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WiredHome 2:8f71b71fce1b 1
WiredHome 2:8f71b71fce1b 2 #include "SignalGenDAC.h"
WiredHome 2:8f71b71fce1b 3
WiredHome 4:10281ddb673d 4 DigitalOut led(LED1);
WiredHome 4:10281ddb673d 5
WiredHome 2:8f71b71fce1b 6 #define PI 3.14159
WiredHome 2:8f71b71fce1b 7
WiredHome 2:8f71b71fce1b 8 /// The linked list structure used to control the DMA transfer
WiredHome 2:8f71b71fce1b 9 ///
WiredHome 2:8f71b71fce1b 10 typedef struct {
WiredHome 2:8f71b71fce1b 11 uint32_t source; /// start of source area
WiredHome 2:8f71b71fce1b 12 uint32_t destination;/// start of destination area
WiredHome 2:8f71b71fce1b 13 uint32_t next; /// address of next strLLI in chain
WiredHome 2:8f71b71fce1b 14 uint32_t control; /// DMACCxControl register
WiredHome 2:8f71b71fce1b 15 } LinkListItem_t;
WiredHome 2:8f71b71fce1b 16
WiredHome 3:d22f3e52d06a 17 /// The DACsignal memory, which is DMA sent to the DAC to play the waveform,
WiredHome 3:d22f3e52d06a 18 /// produced by scaling the VoltSignal array
WiredHome 2:8f71b71fce1b 19 ///
WiredHome 3:d22f3e52d06a 20 float VoltSignal[SIGNAL_MEM_ENTRIES] __attribute__ ((section("AHBSRAM0")));
WiredHome 3:d22f3e52d06a 21 signed long DACsignal[SIGNAL_MEM_ENTRIES] __attribute__ ((section("AHBSRAM0")));
WiredHome 2:8f71b71fce1b 22
WiredHome 2:8f71b71fce1b 23 /// The linked list item record, used by the DMA engine to decide how to play
WiredHome 2:8f71b71fce1b 24 ///
WiredHome 2:8f71b71fce1b 25 LinkListItem_t llio __attribute__ ((section("AHBSRAM0")));
WiredHome 2:8f71b71fce1b 26
WiredHome 2:8f71b71fce1b 27
WiredHome 2:8f71b71fce1b 28 SignalGenDAC::SignalGenDAC(PinName _aout, float _minV, float _maxV) :
WiredHome 2:8f71b71fce1b 29 minV(_minV), maxV(_maxV) {
WiredHome 2:8f71b71fce1b 30 aout = new AnalogOut(_aout);
WiredHome 4:10281ddb673d 31 #if 1
WiredHome 4:10281ddb673d 32 #include "mbed.h"
WiredHome 4:10281ddb673d 33 aout->write(0.25);
WiredHome 4:10281ddb673d 34 wait_ms(25);
WiredHome 4:10281ddb673d 35 aout->write(0.50);
WiredHome 4:10281ddb673d 36 wait_ms(25);
WiredHome 4:10281ddb673d 37 aout->write(0.75);
WiredHome 4:10281ddb673d 38 wait_ms(25);
WiredHome 4:10281ddb673d 39 aout->write(1.00);
WiredHome 4:10281ddb673d 40 wait_ms(25);
WiredHome 4:10281ddb673d 41 #endif
WiredHome 2:8f71b71fce1b 42 }
WiredHome 2:8f71b71fce1b 43
WiredHome 2:8f71b71fce1b 44 SignalGenDAC::~SignalGenDAC() {
WiredHome 2:8f71b71fce1b 45 }
WiredHome 2:8f71b71fce1b 46
WiredHome 2:8f71b71fce1b 47 void SignalGenDAC::Start(bool oneShot) {
WiredHome 4:10281ddb673d 48 printf("Start(%d) w/%d samples\r\n", oneShot ? 1 : 0, numSamples);
WiredHome 3:d22f3e52d06a 49 isOn = (oneShot) ? false : true;
WiredHome 4:10281ddb673d 50 led = 1;
WiredHome 4:10281ddb673d 51
WiredHome 4:10281ddb673d 52 for (int x=0; x<numSamples; x++) {
WiredHome 4:10281ddb673d 53 DACsignal[x] = ((uint16_t)(VoltSignal[x]/maxV * 1023) << 6);
WiredHome 4:10281ddb673d 54 printf("%3d, %5.3f, %d\r\n", x, VoltSignal[x], DACsignal[x]);
WiredHome 4:10281ddb673d 55 }
WiredHome 4:10281ddb673d 56
WiredHome 4:10281ddb673d 57 llio.source = (uint32_t)DACsignal;
WiredHome 4:10281ddb673d 58 llio.destination = (uint32_t)&LPC_DAC->DACR;
WiredHome 4:10281ddb673d 59 llio.next = (uint32_t)&llio;
WiredHome 4:10281ddb673d 60 llio.control = (1<<26) | (2<<21) | (2<<18) | numSamples;
WiredHome 4:10281ddb673d 61
WiredHome 4:10281ddb673d 62 LPC_SC->PCONP |= (1<<29);
WiredHome 4:10281ddb673d 63
WiredHome 4:10281ddb673d 64 /* Enable GPDMA and sync logic */
WiredHome 4:10281ddb673d 65 LPC_GPDMA->DMACConfig = 1;
WiredHome 4:10281ddb673d 66 LPC_GPDMA->DMACSync = (1<<6);
WiredHome 4:10281ddb673d 67
WiredHome 4:10281ddb673d 68 /* Load DMA Channel0 */
WiredHome 4:10281ddb673d 69 LPC_GPDMACH0->DMACCSrcAddr = (uint32_t)DACsignal;
WiredHome 4:10281ddb673d 70 LPC_GPDMACH0->DMACCDestAddr = (uint32_t)&LPC_DAC->DACR;
WiredHome 4:10281ddb673d 71 LPC_GPDMACH0->DMACCLLI = (uint32_t)&llio; // Free Running
WiredHome 4:10281ddb673d 72 //LPC_GPDMACH0->DMACCLLI = 0; // One-Shot
WiredHome 4:10281ddb673d 73
WiredHome 4:10281ddb673d 74 LPC_GPDMACH0->DMACCControl = numSamples // transfer size (0 - 11) = 64
WiredHome 4:10281ddb673d 75 | (0 << 12) // source burst size (12 - 14) = 1
WiredHome 4:10281ddb673d 76 | (0 << 15) // destination burst size (15 - 17) = 1
WiredHome 4:10281ddb673d 77 | (2 << 18) // source width (18 - 20) = 32 bit
WiredHome 4:10281ddb673d 78 | (2 << 21) // destination width (21 - 23) = 32 bit
WiredHome 4:10281ddb673d 79 | (0 << 24) // source AHB select (24) = AHB 0
WiredHome 4:10281ddb673d 80 | (0 << 25) // destination AHB select (25) = AHB 0
WiredHome 4:10281ddb673d 81 | (1 << 26) // source increment (26) = increment
WiredHome 4:10281ddb673d 82 | (0 << 27) // destination increment (27) = no increment
WiredHome 4:10281ddb673d 83 | (0 << 28) // mode select (28) = access in user mode
WiredHome 4:10281ddb673d 84 | (0 << 29) // (29) = access not bufferable
WiredHome 4:10281ddb673d 85 | (0 << 30) // (30) = access not cacheable
WiredHome 4:10281ddb673d 86 | (0 << 31); // terminal count interrupt disabled
WiredHome 4:10281ddb673d 87
WiredHome 4:10281ddb673d 88 LPC_GPDMACH0->DMACCConfig = 1
WiredHome 4:10281ddb673d 89 | (0 << 1) // source peripheral (1 - 5) = none
WiredHome 4:10281ddb673d 90 | (7 << 6) // destination peripheral (6 - 10) = DAC
WiredHome 4:10281ddb673d 91 | (1 << 11) // flow control (11 - 13) = mem to per
WiredHome 4:10281ddb673d 92 | (0 << 14) // (14) = mask out error interrupt
WiredHome 4:10281ddb673d 93 | (0 << 15) // (15) = mask out terminal count interrupt
WiredHome 4:10281ddb673d 94 | (0 << 16) // (16) = no locked transfers
WiredHome 4:10281ddb673d 95 | (0 << 18); // (27) = no HALT
WiredHome 4:10281ddb673d 96
WiredHome 4:10281ddb673d 97 /* DACclk = 25 MHz, so 10 usec interval */
WiredHome 4:10281ddb673d 98 LPC_DAC->DACCNTVAL = 20; // 16-bit reload value
WiredHome 4:10281ddb673d 99 /* DMA, timer running, dbuff */
WiredHome 4:10281ddb673d 100 LPC_DAC->DACCTRL =
WiredHome 4:10281ddb673d 101 1<<3 // DMA_ENA dma burst is enabled
WiredHome 4:10281ddb673d 102 | 1<<2 // CNT_ENA Timeout couner is enabled
WiredHome 4:10281ddb673d 103 | 1<<1; // DBLBUF_ENA double-buffering enabled
WiredHome 2:8f71b71fce1b 104 }
WiredHome 2:8f71b71fce1b 105
WiredHome 2:8f71b71fce1b 106 void SignalGenDAC::Stop(void) {
WiredHome 3:d22f3e52d06a 107 printf("Stop()\r\n");
WiredHome 3:d22f3e52d06a 108 LPC_GPDMACH0->DMACCLLI = 0;
WiredHome 3:d22f3e52d06a 109 isOn = false;
WiredHome 4:10281ddb673d 110 led = 0;
WiredHome 2:8f71b71fce1b 111 }
WiredHome 2:8f71b71fce1b 112
WiredHome 2:8f71b71fce1b 113
WiredHome 2:8f71b71fce1b 114 void SignalGenDAC::PrepareWaveform(SG_Mode mode, float frequency, float dutycycle, float voltage, float offset) {
WiredHome 2:8f71b71fce1b 115 int x, dcCount, firstQtr, lastQtr;
WiredHome 2:8f71b71fce1b 116 float upp = rangelimit(offset + voltage/2, minV, maxV);
WiredHome 2:8f71b71fce1b 117 float mid = rangelimit(offset, minV, maxV);
WiredHome 2:8f71b71fce1b 118 float low = rangelimit(offset - voltage/2, minV, maxV);
WiredHome 2:8f71b71fce1b 119 float v;
WiredHome 4:10281ddb673d 120 numSamples = 32; // Ideally, compute this based on the frequency for good resolution
WiredHome 2:8f71b71fce1b 121 dcCount = dutycycle/100.0 * numSamples;
WiredHome 2:8f71b71fce1b 122 firstQtr = dcCount / 2;
WiredHome 2:8f71b71fce1b 123 lastQtr = dcCount + (numSamples - dcCount)/2;
WiredHome 2:8f71b71fce1b 124
WiredHome 2:8f71b71fce1b 125 // Set the timebased based on the frequency
WiredHome 2:8f71b71fce1b 126 if (isOn) {
WiredHome 4:10281ddb673d 127 Stop();
WiredHome 2:8f71b71fce1b 128 }
WiredHome 4:10281ddb673d 129 printf("Generate wave for mode: %d\r\n", mode);
WiredHome 2:8f71b71fce1b 130 switch (mode) {
WiredHome 2:8f71b71fce1b 131 case SG_SINE:
WiredHome 2:8f71b71fce1b 132 for (x=0; x<numSamples; x++) {
WiredHome 2:8f71b71fce1b 133 if (x < dcCount) {
WiredHome 2:8f71b71fce1b 134 v = offset + voltage/2 * sin(x * 1 * PI / dcCount);
WiredHome 2:8f71b71fce1b 135 } else {
WiredHome 2:8f71b71fce1b 136 v = offset - voltage/2 * sin((x - dcCount) * 1 * PI / (numSamples-dcCount));
WiredHome 2:8f71b71fce1b 137 }
WiredHome 3:d22f3e52d06a 138 v = rangelimit(v, minV, maxV);
WiredHome 3:d22f3e52d06a 139 VoltSignal[x] = v;
WiredHome 2:8f71b71fce1b 140 }
WiredHome 2:8f71b71fce1b 141 break;
WiredHome 2:8f71b71fce1b 142 case SG_SQUARE:
WiredHome 2:8f71b71fce1b 143 for (x=0; x<numSamples; x++) {
WiredHome 2:8f71b71fce1b 144 if (x < dcCount) {
WiredHome 2:8f71b71fce1b 145 v = rangelimit(offset + voltage/2, minV, maxV);
WiredHome 2:8f71b71fce1b 146 } else {
WiredHome 2:8f71b71fce1b 147 v = rangelimit(offset - voltage/2, minV, maxV);
WiredHome 2:8f71b71fce1b 148 }
WiredHome 3:d22f3e52d06a 149 VoltSignal[x] = v;
WiredHome 2:8f71b71fce1b 150 }
WiredHome 2:8f71b71fce1b 151 break;
WiredHome 2:8f71b71fce1b 152 case SG_TRIANGLE:
WiredHome 2:8f71b71fce1b 153 for (x=0; x<numSamples; x++) {
WiredHome 2:8f71b71fce1b 154 if (x < firstQtr) {
WiredHome 3:d22f3e52d06a 155 v = voltage/2 * (float)x/(firstQtr);
WiredHome 3:d22f3e52d06a 156 v += offset;
WiredHome 2:8f71b71fce1b 157 } else if (x < dcCount) {
WiredHome 3:d22f3e52d06a 158 v = voltage/2 * (float)x/(firstQtr);
WiredHome 3:d22f3e52d06a 159 v = voltage - (v - offset);
WiredHome 2:8f71b71fce1b 160 } else if (x < lastQtr) {
WiredHome 3:d22f3e52d06a 161 v = voltage * (float)(x - dcCount)/(numSamples - dcCount);
WiredHome 3:d22f3e52d06a 162 v = offset - v;
WiredHome 2:8f71b71fce1b 163 } else {
WiredHome 3:d22f3e52d06a 164 v = voltage * (float)(x - dcCount)/(numSamples - dcCount);
WiredHome 3:d22f3e52d06a 165 v = v + offset - voltage;
WiredHome 2:8f71b71fce1b 166 }
WiredHome 3:d22f3e52d06a 167 VoltSignal[x] = v;
WiredHome 2:8f71b71fce1b 168 }
WiredHome 2:8f71b71fce1b 169 break;
WiredHome 2:8f71b71fce1b 170 case SG_SAWTOOTH:
WiredHome 2:8f71b71fce1b 171 for (x=0; x<numSamples; x++) {
WiredHome 2:8f71b71fce1b 172 if (x < dcCount) {
WiredHome 3:d22f3e52d06a 173 v = offset - voltage/2 + (float)x/dcCount * voltage/2;
WiredHome 2:8f71b71fce1b 174 } else {
WiredHome 3:d22f3e52d06a 175 v = offset + (float)(x - dcCount)/(numSamples - dcCount) * voltage/2;
WiredHome 2:8f71b71fce1b 176 }
WiredHome 3:d22f3e52d06a 177 v = rangelimit(v, minV, maxV);
WiredHome 3:d22f3e52d06a 178 VoltSignal[x] = v;
WiredHome 2:8f71b71fce1b 179 }
WiredHome 2:8f71b71fce1b 180 break;
WiredHome 2:8f71b71fce1b 181 case SG_USER:
WiredHome 2:8f71b71fce1b 182 break;
WiredHome 2:8f71b71fce1b 183 }
WiredHome 3:d22f3e52d06a 184 //printf("DAC Data %3.2f %3.2f\r\n", voltage, offset);
WiredHome 2:8f71b71fce1b 185 for (x=0; x<numSamples; x++) {
WiredHome 4:10281ddb673d 186 DACsignal[x] = ((uint16_t)(VoltSignal[x]/maxV * 1023) << 6);
WiredHome 4:10281ddb673d 187 printf("%3d, %5.3f, %d\r\n", x, VoltSignal[x], DACsignal[x]);
WiredHome 2:8f71b71fce1b 188 }
WiredHome 4:10281ddb673d 189 Start(false);
WiredHome 2:8f71b71fce1b 190 }
WiredHome 2:8f71b71fce1b 191
WiredHome 2:8f71b71fce1b 192 float SignalGenDAC::rangelimit(float value, float min, float max) {
WiredHome 2:8f71b71fce1b 193 if (value < min)
WiredHome 2:8f71b71fce1b 194 return min;
WiredHome 2:8f71b71fce1b 195 else if (value > max)
WiredHome 2:8f71b71fce1b 196 return max;
WiredHome 2:8f71b71fce1b 197 else
WiredHome 2:8f71b71fce1b 198 return value;
WiredHome 2:8f71b71fce1b 199 }
WiredHome 2:8f71b71fce1b 200