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/*
ChibiOS/GFX - Copyright (C) 2012, 2013
Joel Bodenmann aka Tectu <joel@unormal.org>
This file is part of ChibiOS/GFX.
ChibiOS/GFX is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/GFX is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* --------------------------- Our Custom GWIN Oscilloscope ---------------
*
* This GWIN superset implements a simple audio oscilloscope using the GAUDIN module.
*
* It makes many assumptions, the most fundamental of which is that the audio device
* produces unsigned integer samples.
*
* The GMISC module with GMISC_NEED_ARRAYOPS could be used to process the samples more
* correctly if we were really building something generic.
*/
#include "ch.h"
#include "hal.h"
#include "gfx.h"
#include "gwinosc.h"
/* Include internal GWIN routines so we can build our own superset class */
#include "gwin/internal.h"
/* Our GWIN identifier */
#define GW_SCOPE (GW_FIRST_USER_WINDOW+0)
/* The size of our dynamically allocated audio buffer */
#define AUDIOBUFSZ 64*2
/* How many flat-line sample before we trigger */
#define FLATLINE_SAMPLES 8
GHandle gwinCreateScope(GScopeObject *gs, coord_t x, coord_t y, coord_t cx, coord_t cy, uint16_t channel, uint32_t frequency) {
/* Initialise the base class GWIN */
if (!(gs = (GScopeObject *)_gwinInit((GWindowObject *)gs, x, y, cx, cy, sizeof(GScopeObject))))
return 0;
/* Initialise the scope object members and allocate memory for buffers */
gs->gwin.type = GW_SCOPE;
chBSemInit(&gs->bsem, TRUE);
gs->nextx = 0;
if (!(gs->lastscopetrace = (coord_t *)chHeapAlloc(NULL, gs->gwin.width * sizeof(coord_t))))
return 0;
if (!(gs->audiobuf = (adcsample_t *)chHeapAlloc(NULL, AUDIOBUFSZ * sizeof(adcsample_t))))
return 0;
#if TRIGGER_METHOD == TRIGGER_POSITIVERAMP
gs->lasty = gs->gwin.height/2;
#elif TRIGGER_METHOD == TRIGGER_MINVALUE
gs->lasty = gs->gwin.height/2;
gs->scopemin = 0;
#endif
/* Start the GADC high speed converter */
gaudinInit(channel, frequency, gs->audiobuf, AUDIOBUFSZ, AUDIOBUFSZ/2);
gaudinSetBSem(&gs->bsem, &gs->myEvent);
gaudinStart();
return (GHandle)gs;
}
void gwinWaitForScopeTrace(GHandle gh) {
#define gs ((GScopeObject *)(gh))
int i;
coord_t x, y;
coord_t yoffset;
audin_sample_t *pa;
coord_t *pc;
#if TRIGGER_METHOD == TRIGGER_POSITIVERAMP
bool_t rdytrigger;
int flsamples;
#elif TRIGGER_METHOD == TRIGGER_MINVALUE
bool_t rdytrigger;
int flsamples;
coord_t scopemin;
#endif
/* Wait for a set of audio conversions */
chBSemWait(&gs->bsem);
/* Ensure we are drawing in the right area */
#if GDISP_NEED_CLIP
gdispSetClip(gh->x, gh->y, gh->width, gh->height);
#endif
yoffset = gh->height/2 + (1<<SCOPE_Y_BITS)/2;
x = gs->nextx;
pc = gs->lastscopetrace+x;
pa = gs->myEvent.buffer;
#if TRIGGER_METHOD == TRIGGER_POSITIVERAMP
rdytrigger = FALSE;
flsamples = 0;
#elif TRIGGER_METHOD == TRIGGER_MINVALUE
rdytrigger = FALSE;
flsamples = 0;
scopemin = 0;
#endif
for(i = gs->myEvent.count; i; i--) {
/* Calculate the new scope value - re-scale using simple shifts for efficiency, re-center and y-invert */
#if GAUDIN_BITS_PER_SAMPLE > SCOPE_Y_BITS
y = yoffset - (*pa++ >> (GAUDIN_BITS_PER_SAMPLE - SCOPE_Y_BITS));
#else
y = yoffset - (*pa++ << (SCOPE_Y_BITS - GAUDIN_BITS_PER_SAMPLE));
#endif
#if TRIGGER_METHOD == TRIGGER_MINVALUE
/* Calculate the scopemin ready for the next trace */
if (y > scopemin)
scopemin = y;
#endif
/* Have we reached the end of a scope trace? */
if (x >= gh->width) {
#if TRIGGER_METHOD == TRIGGER_POSITIVERAMP || TRIGGER_METHOD == TRIGGER_MINVALUE
/* Handle triggering - we trigger on the next sample minimum (y value maximum) or a flat-line */
#if TRIGGER_METHOD == TRIGGER_MINVALUE
/* Arm when we reach the sample minimum (y value maximum) of the previous trace */
if (!rdytrigger && y >= gs->scopemin)
rdytrigger = TRUE;
#endif
if (y == gs->lasty) {
/* Trigger if we get too many flat-line samples regardless of the armed state */
if (++flsamples < FLATLINE_SAMPLES)
continue;
flsamples = 0;
} else if (y > gs->lasty) {
gs->lasty = y;
flsamples = 0;
#if TRIGGER_METHOD == TRIGGER_POSITIVERAMP
/* Arm the trigger when samples fall (y increases) ie. negative slope */
rdytrigger = TRUE;
#endif
continue;
} else {
/* If the trigger is armed, Trigger when samples increases (y decreases) ie. positive slope */
gs->lasty = y;
flsamples = 0;
if (!rdytrigger)
continue;
}
/* Ready for a the next trigger cycle */
rdytrigger = FALSE;
#endif
/* Prepare for a scope trace */
x = 0;
pc = gs->lastscopetrace;
}
/* Clear the old scope pixel and then draw the new scope value */
gdispDrawPixel(gh->x+x, gh->y+pc[0], gh->bgcolor);
gdispDrawPixel(gh->x+x, gh->y+y, gh->color);
/* Save the value */
*pc++ = y;
x++;
#if TRIGGER_METHOD == TRIGGER_POSITIVERAMP || TRIGGER_METHOD == TRIGGER_MINVALUE
gs->lasty = y;
#endif
}
gs->nextx = x;
#if TRIGGER_METHOD == TRIGGER_MINVALUE
gs->scopemin = scopemin;
#endif
#undef gs
}