From: Miklos Marton <redacted>
Date: Wed, 10 Jul 2019 09:02:17 +0000 (+0200)
Subject: demo: Add random analog signal generation
X-Git-Url: https://sigrok.org/gitweb/?a=commitdiff_plain;h=4d8338bb96568e316b425cb2aa0d32bce9f7726c;p=libsigrok.git

demo: Add random analog signal generation
---

diff --git a/src/hardware/demo/api.c b/src/hardware/demo/api.c
index 4d4b891c..fcd40157 100644
--- a/src/hardware/demo/api.c
+++ b/src/hardware/demo/api.c
@@ -32,7 +32,7 @@
 #define DEFAULT_NUM_LOGIC_CHANNELS		8
 #define DEFAULT_LOGIC_PATTERN			PATTERN_SIGROK
 
-#define DEFAULT_NUM_ANALOG_CHANNELS		4
+#define DEFAULT_NUM_ANALOG_CHANNELS		5
 
 /* Note: No spaces allowed because of sigrok-cli. */
 static const char *logic_pattern_str[] = {
diff --git a/src/hardware/demo/protocol.c b/src/hardware/demo/protocol.c
index 05be1d31..305ff17c 100644
--- a/src/hardware/demo/protocol.c
+++ b/src/hardware/demo/protocol.c
@@ -244,6 +244,12 @@ SR_PRIV void demo_generate_analog_pattern(struct dev_context *devc)
 	}
 	pattern->num_samples = last_end;
 	devc->analog_patterns[PATTERN_SAWTOOTH] = pattern;
+
+	/* PATTERN_ANALOG_RANDOM */
+	/* Data not filled here, will be generated in send_analog_packet(). */
+	pattern = g_malloc(sizeof(struct analog_pattern));
+	pattern->num_samples = last_end;
+	devc->analog_patterns[PATTERN_ANALOG_RANDOM] = pattern;
 }
 
 static uint64_t encode_number_to_gray(uint64_t nr)
@@ -484,14 +490,26 @@ static void send_analog_packet(struct analog_gen *ag,
 		ag_pattern_pos = analog_pos % pattern->num_samples;
 		sending_now = MIN(analog_todo, pattern->num_samples - ag_pattern_pos);
 		if (ag->amplitude != DEFAULT_ANALOG_AMPLITUDE ||
-			ag->offset != DEFAULT_ANALOG_OFFSET) {
-
-			/* Amplitude or offset changed, modify each sample. */
-			amplitude = ag->amplitude / DEFAULT_ANALOG_AMPLITUDE;
-			offset = ag->offset - DEFAULT_ANALOG_OFFSET;
+			ag->offset != DEFAULT_ANALOG_OFFSET ||
+			ag->pattern == PATTERN_ANALOG_RANDOM) {
+			/*
+			 * Amplitude or offset changed (or we are generating
+			 * random data), modify each sample.
+			 */
+			if (ag->pattern == PATTERN_ANALOG_RANDOM) {
+				amplitude = ag->amplitude / 500.0;
+				offset = ag->offset - DEFAULT_ANALOG_OFFSET - ag->amplitude;
+			} else {
+				amplitude = ag->amplitude / DEFAULT_ANALOG_AMPLITUDE;
+				offset = ag->offset - DEFAULT_ANALOG_OFFSET;
+			}
 			data = ag->packet.data;
-			for (i = 0; i < sending_now; i++)
-				data[i] = pattern->data[ag_pattern_pos + i] * amplitude + offset;
+			for (i = 0; i < sending_now; i++) {
+				if (ag->pattern == PATTERN_ANALOG_RANDOM)
+					data[i] = (rand() % 1000) * amplitude + offset;
+				else
+					data[i] = pattern->data[ag_pattern_pos + i] * amplitude + offset;
+			}
 		} else {
 			/* Amplitude and offset unchanged, use the fast way. */
 			ag->packet.data = pattern->data + ag_pattern_pos;
@@ -504,11 +522,19 @@ static void send_analog_packet(struct analog_gen *ag,
 	} else {
 		ag_pattern_pos = analog_pos % pattern->num_samples;
 		to_avg = MIN(analog_todo, pattern->num_samples - ag_pattern_pos);
-		amplitude = ag->amplitude / DEFAULT_ANALOG_AMPLITUDE;
-		offset = ag->offset - DEFAULT_ANALOG_OFFSET;
+		if (ag->pattern == PATTERN_ANALOG_RANDOM) {
+			amplitude = ag->amplitude / 500.0;
+			offset = ag->offset - DEFAULT_ANALOG_OFFSET - ag->amplitude;
+		} else {
+			amplitude = ag->amplitude / DEFAULT_ANALOG_AMPLITUDE;
+			offset = ag->offset - DEFAULT_ANALOG_OFFSET;
+		}
 
 		for (i = 0; i < to_avg; i++) {
-			value = *(pattern->data + ag_pattern_pos + i) * amplitude + offset;
+			if (ag->pattern == PATTERN_ANALOG_RANDOM)
+				value = (rand() % 1000) * amplitude + offset;
+			else
+				value = *(pattern->data + ag_pattern_pos + i) * amplitude + offset;
 			ag->avg_val = (ag->avg_val + value) / 2;
 			ag->num_avgs++;
 			/* Time to send averaged data? */
diff --git a/src/hardware/demo/protocol.h b/src/hardware/demo/protocol.h
index 9877f553..4156f5ee 100644
--- a/src/hardware/demo/protocol.h
+++ b/src/hardware/demo/protocol.h
@@ -95,6 +95,7 @@ enum analog_pattern_type {
 	PATTERN_SINE,
 	PATTERN_TRIANGLE,
 	PATTERN_SAWTOOTH,
+	PATTERN_ANALOG_RANDOM,
 };
 
 static const char *analog_pattern_str[] = {
@@ -102,6 +103,7 @@ static const char *analog_pattern_str[] = {
 	"sine",
 	"triangle",
 	"sawtooth",
+	"random",
 };
 
 struct analog_pattern {