GADC implementation with demo program

Also includes driver for AT91SAM7 cpu

1 files changed, 183 insertions, 0 deletions

diff --git a/demos/modules/gadc/gwinosc.c b/demos/modules/gadc/gwinosc.c
new file mode 100644
index 00000000..d08fbc0d
--- /dev/null
+++ b/demos/modules/gadc/gwinosc.c
@@ -0,0 +1,183 @@
+/*
+    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 GADC high speed device.
+ */
+#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, uint32_t physdev, 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 */
+	gadcHighSpeedInit(physdev, frequency, gs->audiobuf, AUDIOBUFSZ, AUDIOBUFSZ/2);
+	gadcHighSpeedSetBSem(&gs->bsem, &gs->myEvent);
+	gadcHighSpeedStart();
+
+	return (GHandle)gs;
+}
+
+void gwinWaitForScopeTrace(GHandle gh) {
+	#define 		gs	((GScopeObject *)(gh))
+	int				i;
+	coord_t			x, y;
+	coord_t			yoffset;
+	adcsample_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 GADC_BITS_PER_SAMPLE > SCOPE_Y_BITS
+			y = yoffset - (*pa++ >> (GADC_BITS_PER_SAMPLE - SCOPE_Y_BITS));
+		#else
+			y = yoffset - (*pa++ << (SCOPE_Y_BITS - GADC_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
+}