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Revision 1536

Added by John Sexton over 14 years ago

Merged new BOM vector functions into the trunk and did a "make dist" to recompile the library. Also brought over C file used to test new BOM
function behavior.

View differences:

bom.c
42 42
//so you need to iterate through the mux index in the following order if you want to get
43 43
//the detector readings in order:
44 44
static const char lookup[16] = {7,6,5,0xe,1,4,3,2,0xf,0,0xd,8,0xc,0xb,9,0xa};
45

  
46

  
47
/* *****************************
48
 * BOM Vector Component Tables *
49
 **************************** **/
50

  
51
/*
52
 * The x component of each BOM detector (indexed from 0 to 15)
53
 * was calculated using the following formula:
54
 *
55
 *		x_comp[i] = fix(25 * cos ( 2 * pi / 16 * i) )
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 *
57
 * where "fix" rounds towards 0. If the BOM detectors were superimposed
58
 * onto a 2 dimensional Cartesian space, this effectively calculates the
59
 * x component of the emitter vector where emitter 0 corresponds to an
60
 * angle of 0 radians, 4 -> pi/2, 8 -> pi, ect.
61
 */
62
static const signed int x_comp[16] = {
63
	25,
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	23,
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	17,
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	9,
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	0,
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	-9,
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	-17,
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	-23,
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	-25,
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	-23,
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	-17,
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	-9,
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	0,
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	9,
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	17,
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	23
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};
80

  
81

  
82
/*
83
 * The y component of each BOM detector (indexed from 0 to 15)
84
 * was calculated using the following formula:
85
 *
86
 *		y_comp[i] = fix(25 * sin ( 2 * pi / 16 * i) )
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 *
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 * where "fix" rounds towards 0. If the BOM detectors were superimposed
89
 * onto a 2 dimensional Cartesian space, this effectively calculates the
90
 * x component of the emitter vector where emitter 0 corresponds to an
91
 * angle of 0 radians, 4 -> pi/2, 8 -> pi, ect.
92
 */
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static signed int y_comp[16] = {
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	0,
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	9,
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	17,
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	23,
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	25,
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	23,
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	17,
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	9,
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	0,
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	-9,
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	-17,
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	-23,
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	-25,
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	-23,
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	-17,
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	-9
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};
45 111

  
46 112
// internal function prototypes
47 113
static void bom_select(char which);
......
228 294
}
229 295

  
230 296
/** 
297
 * Compute the net resultant BOM IR vector by scaling each IR unit vector by its intensity
298
 *		and summing over all IR LEDs.
299
 *
300
 * @param v  Pointer to Vector struct to be filled by this function with an x and y net vector
301
 *		component.
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 *
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 * @param usrBOMvals  Pointer to array which holds 16 raw BOM readings which can be used if user
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 *		has already collected BOM information instead of collecting a new data set from the BOM.
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 *
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 * @return  Exit status - Zero for success; negative on error.
307
 **/
308
int bom_get_vector(Vector* v, int* usrBOMvals) {
309

  
310
	/* Store current BOM readings and use them as a weighting factor */
311
	int intensity[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
312

  
313
	/* Arrays for storing the weighted x ("Rightness") and y ("Forwardness")
314
	 * components. Calculated by multiplying the intensity by the x and y
315
	 * component respectively (x and y components are stored in the tables
316
	 * above). */
317
	int weighted_x_comp[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
318
	int weighted_y_comp[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
319
	
320
	/* Accumulators to sum up the net x ("Rightness") and y ("Forwardness")
321
	 * components for the entire robot. */
322
	long net_x_comp = 0;
323
	long net_y_comp = 0;
324

  
325
	int i = 0;
326

  
327
	/* BOM intensity is actually measured as more intense = closer to 0 */
328
	if (usrBOMvals) {
329
		/* Use BOM values collected by user */
330
		for (i = 0; i < 16; i++) {
331
			intensity[i] = 255 - usrBOMvals[i];
332
		}
333
	} else {
334
		/* Collect new set of BOM data */
335
		bom_refresh(BOM_ALL);
336
		for (i = 0; i < 16; i++) {
337
			intensity[i] = 255 - bom_get(i);
338
		}
339
	}
340

  
341
	/* Calculate weighted vector components and accumulate vector sum */
342
	for (i = 0; i < 16; i++) {
343
		weighted_x_comp[i] = intensity[i] * x_comp[i];
344
		weighted_y_comp[i] = intensity[i] * y_comp[i];
345
		net_x_comp += weighted_x_comp[i];
346
		net_y_comp += weighted_y_comp[i];
347
	}
348

  
349
	/* Fill the Vector struct */
350
	v->x = net_x_comp;
351
	v->y = net_y_comp;
352

  
353
	return 0;
354

  
355
}
356

  
357
/** 
358
 * Compute the normalized net resultant BOM IR vector by scaling each IR unit vector by its
359
 *		intensity and summing over all IR LEDs.
360
 *
361
 * @param v  Pointer to Vector struct to be filled by this function with an x and y net vector
362
 *		component.
363
 *
364
 * @param usrBOMvals  Pointer to array which holds 16 raw BOM readings which can be used if user
365
 *		has already collected BOM information instead of collecting a new data set from the BOM.
366
 *
367
 * @return  Exit status - Zero for success; negative on error.
368
 **/
369
int bom_get_norm_vector(Vector* v, int* usrBOMvals) {
370

  
371
	/* Store current BOM readings and use them as a weighting factor */
372
	int intensity[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
373

  
374
	/* Arrays for storing the weighted x ("Rightness") and y ("Forwardness")
375
	 * components. Calculated by multiplying the intensity by the x and y
376
	 * component respectively (x and y components are stored in the tables
377
	 * above). */
378
	int weighted_x_comp[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
379
	int weighted_y_comp[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
380
	
381
	/* Accumulators to sum up the net x ("Rightness") and y ("Forwardness")
382
	 * components for the entire robot. */
383
	long net_x_comp = 0;
384
	long net_y_comp = 0;
385

  
386
	/* Variables used to normalize the net component values */
387
	int total_intensity = 0;
388
	int normalized_net_x_comp = 0;
389
	int normalized_net_y_comp = 0;
390

  
391
	int i = 0;
392

  
393
	/* BOM intensity is actually measured as more intense = closer to 0 */
394
	if (usrBOMvals) {
395
		/* Use BOM values collected by user */
396
		for (i = 0; i < 16; i++) {
397
			intensity[i] = 255 - usrBOMvals[i];
398
		}
399
	} else {
400
		/* Collect new set of BOM data */
401
		bom_refresh(BOM_ALL);
402
		for (i = 0; i < 16; i++) {
403
			intensity[i] = 255 - bom_get(i);
404
		}
405
	}
406

  
407
	/* Calculate weighted vector components and accumulate vector sum */
408
	for (i = 0; i < 16; i++) {
409
		weighted_x_comp[i] = intensity[i] * x_comp[i];
410
		weighted_y_comp[i] = intensity[i] * y_comp[i];
411
		net_x_comp += weighted_x_comp[i];
412
		net_y_comp += weighted_y_comp[i];
413
		total_intensity += intensity[i];
414
	}
415

  
416
	/* Normalize the resultant vector components by the total intensity */
417
	if (total_intensity > 0) {
418
		normalized_net_x_comp = net_x_comp / total_intensity;
419
		normalized_net_y_comp = net_y_comp / total_intensity;
420
	}
421

  
422
	/* Fill the Vector struct */
423
	v->x = normalized_net_x_comp;
424
	v->y = normalized_net_y_comp;
425

  
426
	return 0;
427

  
428
}
429

  
430
/** 
231 431
 * Print a histogram which shows the current BOM intensity values for each of the 16 BOM IR
232 432
 *		sensors. The function will attempt to send the histogram data over USB.
233 433
 *
234 434
 * @param curBOMvals  Pointer to an array of the current BOM values (the array must have
235 435
 *		length 16). Use this to print values you have already collected. Otherwise pass in NULL
236 436
 *		and bom_refresh() will be called and the current BOM intensity values will be collected.
437
 * @return  Exit status - Zero for success; negative on error.
237 438
 **/
238
void bom_print_usb(int* usrBOMvals) {
439
int bom_print_usb(int* usrBOMvals) {
239 440

  
240 441
	int i, j, max = -1;
241 442
	int curVals[16];
......
279 480
		usb_puts("\r\n");
280 481
	}
281 482
	usb_puts("\r\n");
483

  
484
	return 0;
282 485

  
283 486
}
284 487

  

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