SigGen - Signal Generator - Square, Sine. Arbitrary with …

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Stephen Price / Mbed 2 deprecated SigGen

Signal Generator - Square, Sine. Arbitrary with mods

SigGen.cpp@0:e4b2af8e875a, 2010-07-22 (annotated)

Committer:: smpedi
Date:: Thu Jul 22 14:24:52 2010 +0000
Revision:: 0:e4b2af8e875a

Who changed what in which revision?

User	Revision	Line number	New contents of line
smpedi	0:e4b2af8e875a	1	#include "mbed.h"
smpedi	0:e4b2af8e875a	2
smpedi	0:e4b2af8e875a	3	#define MAXWAVEPTS 20
smpedi	0:e4b2af8e875a	4	#define SQUARE 0
smpedi	0:e4b2af8e875a	5	#define SINE 1
smpedi	0:e4b2af8e875a	6	#define UP 65
smpedi	0:e4b2af8e875a	7	#define DOWN 66
smpedi	0:e4b2af8e875a	8	#define RIGHT 67
smpedi	0:e4b2af8e875a	9	#define LEFT 68
smpedi	0:e4b2af8e875a	10
smpedi	0:e4b2af8e875a	11	AnalogOut wave(p18);
smpedi	0:e4b2af8e875a	12	Ticker timer;
smpedi	0:e4b2af8e875a	13	float wValue;
smpedi	0:e4b2af8e875a	14	float waveVals[MAXWAVEPTS];
smpedi	0:e4b2af8e875a	15	float fpW, fpEnd;
smpedi	0:e4b2af8e875a	16	float fAmp, fModAmp;
smpedi	0:e4b2af8e875a	17	short itype;
smpedi	0:e4b2af8e875a	18
smpedi	0:e4b2af8e875a	19	void init_wave(int, int);
smpedi	0:e4b2af8e875a	20	void write_wavePt();
smpedi	0:e4b2af8e875a	21	int DoTermIO(char);
smpedi	0:e4b2af8e875a	22	void ChangeRate(float);
smpedi	0:e4b2af8e875a	23	extern float input_control();
smpedi	0:e4b2af8e875a	24	extern void ledOut(int);
smpedi	0:e4b2af8e875a	25
smpedi	0:e4b2af8e875a	26	DigitalOut oled(p8);
smpedi	0:e4b2af8e875a	27	Serial pc(USBTX, USBRX); // tx, rx
smpedi	0:e4b2af8e875a	28
smpedi	0:e4b2af8e875a	29	int main() {
smpedi	0:e4b2af8e875a	30	float rate, delay;
smpedi	0:e4b2af8e875a	31	unsigned int idelay;
smpedi	0:e4b2af8e875a	32	char c;
smpedi	0:e4b2af8e875a	33
smpedi	0:e4b2af8e875a	34	fAmp = 0.606f;
smpedi	0:e4b2af8e875a	35	fModAmp = 0.5f;
smpedi	0:e4b2af8e875a	36	pc.printf("\fFrequency (Hz)? ");
smpedi	0:e4b2af8e875a	37	pc.scanf("%f",&rate);
smpedi	0:e4b2af8e875a	38	if (rate > 2000.0f) rate = 2000.0f;
smpedi	0:e4b2af8e875a	39	pc.printf("\n%f Hz, Got it\nSine (1) or Square? (0)",rate);
smpedi	0:e4b2af8e875a	40	pc.scanf("%c",&c);
smpedi	0:e4b2af8e875a	41	itype = c - 48;
smpedi	0:e4b2af8e875a	42	pc.printf("\nType is %s \n",(itype ? "Sine" : "Square"));
smpedi	0:e4b2af8e875a	43
smpedi	0:e4b2af8e875a	44	delay = 1000000 / rate; // delay for one cycle
smpedi	0:e4b2af8e875a	45	delay = delay / (float)(MAXWAVEPTS - 1); // delay per point
smpedi	0:e4b2af8e875a	46	idelay = (int)(delay); // delay in int format
smpedi	0:e4b2af8e875a	47	init_wave((int)MAXWAVEPTS, itype);
smpedi	0:e4b2af8e875a	48
smpedi	0:e4b2af8e875a	49	pc.printf("\nrate = %f\n",rate);
smpedi	0:e4b2af8e875a	50	pc.printf("delay = %f\n",delay);
smpedi	0:e4b2af8e875a	51	pc.printf("idelay = %u micro-seconds\n",idelay);
smpedi	0:e4b2af8e875a	52
smpedi	0:e4b2af8e875a	53	timer.attach_us(&write_wavePt,idelay);
smpedi	0:e4b2af8e875a	54	oled = 0;
smpedi	0:e4b2af8e875a	55	while (1) {
smpedi	0:e4b2af8e875a	56	switch (DoTermIO(pc.getc())) {
smpedi	0:e4b2af8e875a	57	case 'i':
smpedi	0:e4b2af8e875a	58	fModAmp *= 1.01;
smpedi	0:e4b2af8e875a	59	if (fModAmp > 1.0)
smpedi	0:e4b2af8e875a	60	fModAmp = 1.0;
smpedi	0:e4b2af8e875a	61	init_wave((int)MAXWAVEPTS, itype);
smpedi	0:e4b2af8e875a	62	break;
smpedi	0:e4b2af8e875a	63	case 'd':
smpedi	0:e4b2af8e875a	64	fModAmp *= 0.99;
smpedi	0:e4b2af8e875a	65	if (fModAmp < 0.05)
smpedi	0:e4b2af8e875a	66	fModAmp = 0.05;
smpedi	0:e4b2af8e875a	67	init_wave((int)MAXWAVEPTS, itype);
smpedi	0:e4b2af8e875a	68	break;
smpedi	0:e4b2af8e875a	69
smpedi	0:e4b2af8e875a	70	case UP:
smpedi	0:e4b2af8e875a	71	rate += 1.0f;
smpedi	0:e4b2af8e875a	72	ChangeRate(rate);
smpedi	0:e4b2af8e875a	73	break;
smpedi	0:e4b2af8e875a	74	case DOWN:
smpedi	0:e4b2af8e875a	75	rate -= 1.0f;
smpedi	0:e4b2af8e875a	76	ChangeRate(rate);
smpedi	0:e4b2af8e875a	77	break;
smpedi	0:e4b2af8e875a	78	case RIGHT:
smpedi	0:e4b2af8e875a	79	rate += 25.0f;
smpedi	0:e4b2af8e875a	80	ChangeRate(rate);
smpedi	0:e4b2af8e875a	81	break;
smpedi	0:e4b2af8e875a	82	case LEFT:
smpedi	0:e4b2af8e875a	83	rate -= 25.0f;
smpedi	0:e4b2af8e875a	84	ChangeRate(rate);
smpedi	0:e4b2af8e875a	85	break;
smpedi	0:e4b2af8e875a	86	case -1:
smpedi	0:e4b2af8e875a	87	pc.printf("%c",12);
smpedi	0:e4b2af8e875a	88	break;
smpedi	0:e4b2af8e875a	89	}
smpedi	0:e4b2af8e875a	90	}
smpedi	0:e4b2af8e875a	91	}
smpedi	0:e4b2af8e875a	92
smpedi	0:e4b2af8e875a	93	int DoTermIO(char c) {
smpedi	0:e4b2af8e875a	94	char e;
smpedi	0:e4b2af8e875a	95
smpedi	0:e4b2af8e875a	96	if (c==17)
smpedi	0:e4b2af8e875a	97	return(-1);
smpedi	0:e4b2af8e875a	98
smpedi	0:e4b2af8e875a	99	if (c == 27) { // escape sequence?
smpedi	0:e4b2af8e875a	100	e = pc.getc();
smpedi	0:e4b2af8e875a	101	if (e != 91) {
smpedi	0:e4b2af8e875a	102	return((int)(-1));
smpedi	0:e4b2af8e875a	103	}
smpedi	0:e4b2af8e875a	104	pc.printf("%c",c);
smpedi	0:e4b2af8e875a	105	return((int)(pc.getc()));
smpedi	0:e4b2af8e875a	106	}
smpedi	0:e4b2af8e875a	107	pc.putc(c);
smpedi	0:e4b2af8e875a	108	return((int)c);
smpedi	0:e4b2af8e875a	109	}
smpedi	0:e4b2af8e875a	110
smpedi	0:e4b2af8e875a	111
smpedi	0:e4b2af8e875a	112	void ChangeRate(float val) {
smpedi	0:e4b2af8e875a	113	int idelay;
smpedi	0:e4b2af8e875a	114	float delay;
smpedi	0:e4b2af8e875a	115
smpedi	0:e4b2af8e875a	116	pc.printf("\f");
smpedi	0:e4b2af8e875a	117	pc.printf(" FFreq = %8.0f",val);
smpedi	0:e4b2af8e875a	118
smpedi	0:e4b2af8e875a	119	delay = 1000000 / val; // delay for one cycle
smpedi	0:e4b2af8e875a	120	delay = delay / (float)(MAXWAVEPTS - 1); // delay per point
smpedi	0:e4b2af8e875a	121	idelay = (int)(delay); // delay in int format
smpedi	0:e4b2af8e875a	122
smpedi	0:e4b2af8e875a	123	pc.printf("\nrate = %f\n",val);
smpedi	0:e4b2af8e875a	124	pc.printf("delay = %f\n",delay);
smpedi	0:e4b2af8e875a	125	pc.printf("idelay = %u micro-seconds\n",idelay);
smpedi	0:e4b2af8e875a	126	timer.detach();
smpedi	0:e4b2af8e875a	127	timer = Ticker();
smpedi	0:e4b2af8e875a	128	timer.attach_us(&write_wavePt,idelay);
smpedi	0:e4b2af8e875a	129	}
smpedi	0:e4b2af8e875a	130
smpedi	0:e4b2af8e875a	131
smpedi	0:e4b2af8e875a	132	void write_wavePt
smpedi	0:e4b2af8e875a	133
smpedi	0:e4b2af8e875a	134	if (fpW >= fpEnd) {
smpedi	0:e4b2af8e875a	135	fpW = waveVals;
smpedi	0:e4b2af8e875a	136	}
smpedi	0:e4b2af8e875a	137	wave.write(*fpW);
smpedi	0:e4b2af8e875a	138	}
smpedi	0:e4b2af8e875a	139
smpedi	0:e4b2af8e875a	140	/* load wave array with values. Currently supports square and sine, but any
smpedi	0:e4b2af8e875a	141	arbitrary wave shape can be defined, as long as it is MAXWAVEPTS long
smpedi	0:e4b2af8e875a	142	*/
smpedi	0:e4b2af8e875a	143
smpedi	0:e4b2af8e875a	144	void init_wave(int iNumPts, int itype) {
smpedi	0:e4b2af8e875a	145	int i, iMid;
smpedi	0:e4b2af8e875a	146	float fddeg, fdeg, pi;
smpedi	0:e4b2af8e875a	147	float *fp;
smpedi	0:e4b2af8e875a	148	float amp;
smpedi	0:e4b2af8e875a	149
smpedi	0:e4b2af8e875a	150	amp = fAmp * fModAmp;
smpedi	0:e4b2af8e875a	151	switch (itype) {
smpedi	0:e4b2af8e875a	152	case SQUARE: // square
smpedi	0:e4b2af8e875a	153	iMid = iNumPts/2-1;
smpedi	0:e4b2af8e875a	154	fpW = waveVals;
smpedi	0:e4b2af8e875a	155	fp = fpW;
smpedi	0:e4b2af8e875a	156	for (i=0; i<iMid; i++) {
smpedi	0:e4b2af8e875a	157	*fp = 0.0;
smpedi	0:e4b2af8e875a	158	fp++;
smpedi	0:e4b2af8e875a	159	}
smpedi	0:e4b2af8e875a	160	for (i=iMid; i< iNumPts; i++) {
smpedi	0:e4b2af8e875a	161	fp = amp 2;
smpedi	0:e4b2af8e875a	162	fp++;
smpedi	0:e4b2af8e875a	163	}
smpedi	0:e4b2af8e875a	164	fpEnd = fp-1;
smpedi	0:e4b2af8e875a	165	break;
smpedi	0:e4b2af8e875a	166
smpedi	0:e4b2af8e875a	167	case SINE: // sine
smpedi	0:e4b2af8e875a	168	pi = 3.1415926;
smpedi	0:e4b2af8e875a	169	fddeg = ((2.0f * pi) / (float)iNumPts);
smpedi	0:e4b2af8e875a	170	fpW = waveVals;
smpedi	0:e4b2af8e875a	171	fp = fpW;
smpedi	0:e4b2af8e875a	172	fdeg = 0;
smpedi	0:e4b2af8e875a	173	for (i=0; i<iNumPts; i++) {
smpedi	0:e4b2af8e875a	174	fp =( amp cos(fdeg)) + amp;
smpedi	0:e4b2af8e875a	175	fp++;
smpedi	0:e4b2af8e875a	176	fdeg += fddeg;
smpedi	0:e4b2af8e875a	177	}
smpedi	0:e4b2af8e875a	178	fpEnd = fp-1;
smpedi	0:e4b2af8e875a	179
smpedi	0:e4b2af8e875a	180	break;
smpedi	0:e4b2af8e875a	181	}
smpedi	0:e4b2af8e875a	182
smpedi	0:e4b2af8e875a	183	}
smpedi	0:e4b2af8e875a	184

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	22 Jul 2010
Imports:	149
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	2

SigGen.cpp@0:e4b2af8e875a, 2010-07-22 (annotated)

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