Signal Generator
Dependencies: IniManager RA8875 Watchdog mbed-rtos mbed
Fork of speaker_demo_Analog by
SignalGenDAC.cpp@3:d22f3e52d06a, 2017-01-16 (annotated)
- Committer:
- WiredHome
- Date:
- Mon Jan 16 04:33:06 2017 +0000
- Revision:
- 3:d22f3e52d06a
- Parent:
- 2:8f71b71fce1b
- Child:
- 4:10281ddb673d
Added button for Start/Stop/Pulse
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
WiredHome | 2:8f71b71fce1b | 1 | |
WiredHome | 2:8f71b71fce1b | 2 | #include "SignalGenDAC.h" |
WiredHome | 2:8f71b71fce1b | 3 | |
WiredHome | 2:8f71b71fce1b | 4 | #define PI 3.14159 |
WiredHome | 2:8f71b71fce1b | 5 | |
WiredHome | 2:8f71b71fce1b | 6 | /// The linked list structure used to control the DMA transfer |
WiredHome | 2:8f71b71fce1b | 7 | /// |
WiredHome | 2:8f71b71fce1b | 8 | typedef struct { |
WiredHome | 2:8f71b71fce1b | 9 | uint32_t source; /// start of source area |
WiredHome | 2:8f71b71fce1b | 10 | uint32_t destination;/// start of destination area |
WiredHome | 2:8f71b71fce1b | 11 | uint32_t next; /// address of next strLLI in chain |
WiredHome | 2:8f71b71fce1b | 12 | uint32_t control; /// DMACCxControl register |
WiredHome | 2:8f71b71fce1b | 13 | } LinkListItem_t; |
WiredHome | 2:8f71b71fce1b | 14 | |
WiredHome | 3:d22f3e52d06a | 15 | /// The DACsignal memory, which is DMA sent to the DAC to play the waveform, |
WiredHome | 3:d22f3e52d06a | 16 | /// produced by scaling the VoltSignal array |
WiredHome | 2:8f71b71fce1b | 17 | /// |
WiredHome | 3:d22f3e52d06a | 18 | float VoltSignal[SIGNAL_MEM_ENTRIES] __attribute__ ((section("AHBSRAM0"))); |
WiredHome | 3:d22f3e52d06a | 19 | signed long DACsignal[SIGNAL_MEM_ENTRIES] __attribute__ ((section("AHBSRAM0"))); |
WiredHome | 2:8f71b71fce1b | 20 | |
WiredHome | 2:8f71b71fce1b | 21 | /// The linked list item record, used by the DMA engine to decide how to play |
WiredHome | 2:8f71b71fce1b | 22 | /// |
WiredHome | 2:8f71b71fce1b | 23 | LinkListItem_t llio __attribute__ ((section("AHBSRAM0"))); |
WiredHome | 2:8f71b71fce1b | 24 | |
WiredHome | 2:8f71b71fce1b | 25 | |
WiredHome | 2:8f71b71fce1b | 26 | SignalGenDAC::SignalGenDAC(PinName _aout, float _minV, float _maxV) : |
WiredHome | 2:8f71b71fce1b | 27 | minV(_minV), maxV(_maxV) { |
WiredHome | 2:8f71b71fce1b | 28 | aout = new AnalogOut(_aout); |
WiredHome | 2:8f71b71fce1b | 29 | } |
WiredHome | 2:8f71b71fce1b | 30 | |
WiredHome | 2:8f71b71fce1b | 31 | SignalGenDAC::~SignalGenDAC() { |
WiredHome | 2:8f71b71fce1b | 32 | } |
WiredHome | 2:8f71b71fce1b | 33 | |
WiredHome | 2:8f71b71fce1b | 34 | void SignalGenDAC::Start(bool oneShot) { |
WiredHome | 3:d22f3e52d06a | 35 | printf("Start(%d)\r\n", oneShot ? 1 : 0); |
WiredHome | 3:d22f3e52d06a | 36 | LPC_GPDMACH0->DMACCLLI = (oneShot) ? 0 : (uint32_t) &llio; |
WiredHome | 3:d22f3e52d06a | 37 | isOn = (oneShot) ? false : true; |
WiredHome | 2:8f71b71fce1b | 38 | } |
WiredHome | 2:8f71b71fce1b | 39 | |
WiredHome | 2:8f71b71fce1b | 40 | void SignalGenDAC::Stop(void) { |
WiredHome | 3:d22f3e52d06a | 41 | printf("Stop()\r\n"); |
WiredHome | 3:d22f3e52d06a | 42 | LPC_GPDMACH0->DMACCLLI = 0; |
WiredHome | 3:d22f3e52d06a | 43 | isOn = false; |
WiredHome | 2:8f71b71fce1b | 44 | } |
WiredHome | 2:8f71b71fce1b | 45 | |
WiredHome | 2:8f71b71fce1b | 46 | |
WiredHome | 2:8f71b71fce1b | 47 | void SignalGenDAC::PrepareWaveform(SG_Mode mode, float frequency, float dutycycle, float voltage, float offset) { |
WiredHome | 2:8f71b71fce1b | 48 | int x, dcCount, firstQtr, lastQtr; |
WiredHome | 2:8f71b71fce1b | 49 | float upp = rangelimit(offset + voltage/2, minV, maxV); |
WiredHome | 2:8f71b71fce1b | 50 | float mid = rangelimit(offset, minV, maxV); |
WiredHome | 2:8f71b71fce1b | 51 | float low = rangelimit(offset - voltage/2, minV, maxV); |
WiredHome | 2:8f71b71fce1b | 52 | float v; |
WiredHome | 2:8f71b71fce1b | 53 | int numSamples = 32; // Ideally, compute this based on the frequency for good resolution |
WiredHome | 2:8f71b71fce1b | 54 | dcCount = dutycycle/100.0 * numSamples; |
WiredHome | 2:8f71b71fce1b | 55 | firstQtr = dcCount / 2; |
WiredHome | 2:8f71b71fce1b | 56 | lastQtr = dcCount + (numSamples - dcCount)/2; |
WiredHome | 2:8f71b71fce1b | 57 | |
WiredHome | 2:8f71b71fce1b | 58 | // Set the timebased based on the frequency |
WiredHome | 2:8f71b71fce1b | 59 | if (isOn) { |
WiredHome | 2:8f71b71fce1b | 60 | // stop the signal during the change |
WiredHome | 2:8f71b71fce1b | 61 | isOn = false; |
WiredHome | 2:8f71b71fce1b | 62 | } |
WiredHome | 2:8f71b71fce1b | 63 | switch (mode) { |
WiredHome | 2:8f71b71fce1b | 64 | case SG_SINE: |
WiredHome | 2:8f71b71fce1b | 65 | for (x=0; x<numSamples; x++) { |
WiredHome | 2:8f71b71fce1b | 66 | if (x < dcCount) { |
WiredHome | 2:8f71b71fce1b | 67 | v = offset + voltage/2 * sin(x * 1 * PI / dcCount); |
WiredHome | 2:8f71b71fce1b | 68 | } else { |
WiredHome | 2:8f71b71fce1b | 69 | v = offset - voltage/2 * sin((x - dcCount) * 1 * PI / (numSamples-dcCount)); |
WiredHome | 2:8f71b71fce1b | 70 | } |
WiredHome | 3:d22f3e52d06a | 71 | v = rangelimit(v, minV, maxV); |
WiredHome | 3:d22f3e52d06a | 72 | VoltSignal[x] = v; |
WiredHome | 2:8f71b71fce1b | 73 | } |
WiredHome | 2:8f71b71fce1b | 74 | break; |
WiredHome | 2:8f71b71fce1b | 75 | case SG_SQUARE: |
WiredHome | 2:8f71b71fce1b | 76 | for (x=0; x<numSamples; x++) { |
WiredHome | 2:8f71b71fce1b | 77 | if (x < dcCount) { |
WiredHome | 2:8f71b71fce1b | 78 | v = rangelimit(offset + voltage/2, minV, maxV); |
WiredHome | 2:8f71b71fce1b | 79 | } else { |
WiredHome | 2:8f71b71fce1b | 80 | v = rangelimit(offset - voltage/2, minV, maxV); |
WiredHome | 2:8f71b71fce1b | 81 | } |
WiredHome | 3:d22f3e52d06a | 82 | VoltSignal[x] = v; |
WiredHome | 2:8f71b71fce1b | 83 | } |
WiredHome | 2:8f71b71fce1b | 84 | break; |
WiredHome | 2:8f71b71fce1b | 85 | case SG_TRIANGLE: |
WiredHome | 2:8f71b71fce1b | 86 | for (x=0; x<numSamples; x++) { |
WiredHome | 2:8f71b71fce1b | 87 | if (x < firstQtr) { |
WiredHome | 3:d22f3e52d06a | 88 | v = voltage/2 * (float)x/(firstQtr); |
WiredHome | 3:d22f3e52d06a | 89 | v += offset; |
WiredHome | 2:8f71b71fce1b | 90 | } else if (x < dcCount) { |
WiredHome | 3:d22f3e52d06a | 91 | v = voltage/2 * (float)x/(firstQtr); |
WiredHome | 3:d22f3e52d06a | 92 | v = voltage - (v - offset); |
WiredHome | 2:8f71b71fce1b | 93 | } else if (x < lastQtr) { |
WiredHome | 3:d22f3e52d06a | 94 | v = voltage * (float)(x - dcCount)/(numSamples - dcCount); |
WiredHome | 3:d22f3e52d06a | 95 | v = offset - v; |
WiredHome | 2:8f71b71fce1b | 96 | } else { |
WiredHome | 3:d22f3e52d06a | 97 | v = voltage * (float)(x - dcCount)/(numSamples - dcCount); |
WiredHome | 3:d22f3e52d06a | 98 | v = v + offset - voltage; |
WiredHome | 2:8f71b71fce1b | 99 | } |
WiredHome | 3:d22f3e52d06a | 100 | VoltSignal[x] = v; |
WiredHome | 2:8f71b71fce1b | 101 | } |
WiredHome | 2:8f71b71fce1b | 102 | break; |
WiredHome | 2:8f71b71fce1b | 103 | case SG_SAWTOOTH: |
WiredHome | 2:8f71b71fce1b | 104 | for (x=0; x<numSamples; x++) { |
WiredHome | 2:8f71b71fce1b | 105 | if (x < dcCount) { |
WiredHome | 3:d22f3e52d06a | 106 | v = offset - voltage/2 + (float)x/dcCount * voltage/2; |
WiredHome | 2:8f71b71fce1b | 107 | } else { |
WiredHome | 3:d22f3e52d06a | 108 | v = offset + (float)(x - dcCount)/(numSamples - dcCount) * voltage/2; |
WiredHome | 2:8f71b71fce1b | 109 | } |
WiredHome | 3:d22f3e52d06a | 110 | v = rangelimit(v, minV, maxV); |
WiredHome | 3:d22f3e52d06a | 111 | VoltSignal[x] = v; |
WiredHome | 2:8f71b71fce1b | 112 | } |
WiredHome | 2:8f71b71fce1b | 113 | break; |
WiredHome | 2:8f71b71fce1b | 114 | case SG_USER: |
WiredHome | 2:8f71b71fce1b | 115 | break; |
WiredHome | 2:8f71b71fce1b | 116 | } |
WiredHome | 3:d22f3e52d06a | 117 | //printf("DAC Data %3.2f %3.2f\r\n", voltage, offset); |
WiredHome | 2:8f71b71fce1b | 118 | for (x=0; x<numSamples; x++) { |
WiredHome | 3:d22f3e52d06a | 119 | DACsignal[x] = ((uint16_t)(VoltSignal[x]/maxV * 1023) << 6) | (1 << 16); |
WiredHome | 3:d22f3e52d06a | 120 | //printf("%3d, %5.3f, %d\r\n", x, VoltSignal[x], DACsignal[x]); |
WiredHome | 2:8f71b71fce1b | 121 | } |
WiredHome | 3:d22f3e52d06a | 122 | llio.source = (uint32_t)&DACsignal; |
WiredHome | 3:d22f3e52d06a | 123 | llio.destination = (uint32_t)&LPC_DAC->DACR; |
WiredHome | 3:d22f3e52d06a | 124 | llio.next = (uint32_t)&llio; |
WiredHome | 3:d22f3e52d06a | 125 | llio.control = (1<<26) | (2<<21) | (2<<18) | numSamples; |
WiredHome | 3:d22f3e52d06a | 126 | |
WiredHome | 3:d22f3e52d06a | 127 | LPC_SC->PCONP |= (1<<29); |
WiredHome | 3:d22f3e52d06a | 128 | |
WiredHome | 3:d22f3e52d06a | 129 | /* Enable GPDMA and sync logic */ |
WiredHome | 3:d22f3e52d06a | 130 | LPC_GPDMA->DMACConfig = 1; |
WiredHome | 3:d22f3e52d06a | 131 | LPC_GPDMA->DMACSync = (1<<6); |
WiredHome | 3:d22f3e52d06a | 132 | |
WiredHome | 3:d22f3e52d06a | 133 | /* Load DMA Channel0 */ |
WiredHome | 3:d22f3e52d06a | 134 | LPC_GPDMACH0->DMACCSrcAddr = (uint32_t) &DACsignal[0]; |
WiredHome | 3:d22f3e52d06a | 135 | LPC_GPDMACH0->DMACCDestAddr = (uint32_t) &LPC_DAC->DACR; |
WiredHome | 3:d22f3e52d06a | 136 | |
WiredHome | 3:d22f3e52d06a | 137 | // Free Running |
WiredHome | 3:d22f3e52d06a | 138 | LPC_GPDMACH0->DMACCLLI = (uint32_t) &llio; |
WiredHome | 3:d22f3e52d06a | 139 | // One-Shot |
WiredHome | 3:d22f3e52d06a | 140 | // LPC_GPDMACH0->DMACCLLI = 0; |
WiredHome | 3:d22f3e52d06a | 141 | |
WiredHome | 3:d22f3e52d06a | 142 | LPC_DAC->DACCNTVAL = numSamples // transfer size (0 - 11) = 64 |
WiredHome | 3:d22f3e52d06a | 143 | | (0 << 12) // source burst size (12 - 14) = 1 |
WiredHome | 3:d22f3e52d06a | 144 | | (0 << 15) // destination burst size (15 - 17) = 1 |
WiredHome | 3:d22f3e52d06a | 145 | | (2 << 18) // source width (18 - 20) = 32 bit |
WiredHome | 3:d22f3e52d06a | 146 | | (2 << 21) // destination width (21 - 23) = 32 bit |
WiredHome | 3:d22f3e52d06a | 147 | | (0 << 24) // source AHB select (24) = AHB 0 |
WiredHome | 3:d22f3e52d06a | 148 | | (0 << 25) // destination AHB select (25) = AHB 0 |
WiredHome | 3:d22f3e52d06a | 149 | | (1 << 26) // source increment (26) = increment |
WiredHome | 3:d22f3e52d06a | 150 | | (0 << 27) // destination increment (27) = no increment |
WiredHome | 3:d22f3e52d06a | 151 | | (0 << 28) // mode select (28) = access in user mode |
WiredHome | 3:d22f3e52d06a | 152 | | (0 << 29) // (29) = access not bufferable |
WiredHome | 3:d22f3e52d06a | 153 | | (0 << 30) // (30) = access not cacheable |
WiredHome | 3:d22f3e52d06a | 154 | | (0 << 31); // terminal count interrupt disabled |
WiredHome | 3:d22f3e52d06a | 155 | |
WiredHome | 3:d22f3e52d06a | 156 | LPC_GPDMA->DMACConfig = 1 |
WiredHome | 3:d22f3e52d06a | 157 | | (0 << 1) // source peripheral (1 - 5) = none |
WiredHome | 3:d22f3e52d06a | 158 | | (7 << 6) // destination peripheral (6 - 10) = DAC |
WiredHome | 3:d22f3e52d06a | 159 | | (1 << 11) // flow control (11 - 13) = mem to per |
WiredHome | 3:d22f3e52d06a | 160 | | (0 << 14) // (14) = mask out error interrupt |
WiredHome | 3:d22f3e52d06a | 161 | | (0 << 15) // (15) = mask out terminal count interrupt |
WiredHome | 3:d22f3e52d06a | 162 | | (0 << 16) // (16) = no locked transfers |
WiredHome | 3:d22f3e52d06a | 163 | | (0 << 18); // (27) = no HALT |
WiredHome | 3:d22f3e52d06a | 164 | |
WiredHome | 3:d22f3e52d06a | 165 | /* DACclk = 25 MHz, so 10 usec interval */ |
WiredHome | 3:d22f3e52d06a | 166 | LPC_DAC->DACCNTVAL = 250; // 16-bit reload value |
WiredHome | 3:d22f3e52d06a | 167 | /* DMA, timer running, dbuff */ |
WiredHome | 3:d22f3e52d06a | 168 | LPC_DAC->DACCTRL = |
WiredHome | 3:d22f3e52d06a | 169 | 1<<3 // DMA_ENA dma burst is enabled |
WiredHome | 3:d22f3e52d06a | 170 | | 1<<2 // CNT_ENA Timeout couner is enabled |
WiredHome | 3:d22f3e52d06a | 171 | | 1<<1; // DBLBUF_ENA double-buffering enabled |
WiredHome | 2:8f71b71fce1b | 172 | } |
WiredHome | 2:8f71b71fce1b | 173 | |
WiredHome | 2:8f71b71fce1b | 174 | float SignalGenDAC::rangelimit(float value, float min, float max) { |
WiredHome | 2:8f71b71fce1b | 175 | if (value < min) |
WiredHome | 2:8f71b71fce1b | 176 | return min; |
WiredHome | 2:8f71b71fce1b | 177 | else if (value > max) |
WiredHome | 2:8f71b71fce1b | 178 | return max; |
WiredHome | 2:8f71b71fce1b | 179 | else |
WiredHome | 2:8f71b71fce1b | 180 | return value; |
WiredHome | 2:8f71b71fce1b | 181 | } |
WiredHome | 2:8f71b71fce1b | 182 |