Add DSM decoder test

unittests/CMakeLists.txt

@@ -153,6 +153,12 @@ add_executable(sbus2_test sbus2_test.cpp hrt.cpp
 target_link_libraries( sbus2_test px4_platform )
 add_gtest(sbus2_test)
 
+# DSM test
+add_executable(dsm_test dsm_test.cpp hrt.cpp
+                          ${PX_SRC}/lib/rc/dsm.c)
+target_link_libraries( dsm_test px4_platform )
+add_gtest(dsm_test)
+
 # st24_test
 add_executable(rc_input_test st24_test.cpp hrt.cpp ${PX_SRC}/lib/rc/st24.c sumd_test.cpp ${PX_SRC}/lib/rc/sumd.c)
 target_link_libraries(rc_input_test px4_platform)

unittests/dsm_test.cpp

@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../../src/systemcmds/tests/tests.h"
+#include <drivers/drv_hrt.h>
+// Enable DSM parser output
+#define DSM_DEBUG
+#include <rc/dsm.h>
+#include <systemlib/err.h>
+#include <systemlib/mixer/mixer.h>
+
+#include "gtest/gtest.h"
+
+TEST(DSMTest, DSM)
+{
+	const char *filepath = "testdata/dsm_x_data.txt";
+
+	FILE *fp;
+	fp = fopen(filepath, "rt");
+
+	ASSERT_TRUE(fp);
+	warnx("loading data from: %s", filepath);
+
+	float f;
+	unsigned x;
+	int ret;
+
+	// Trash the first 20 lines
+	for (unsigned i = 0; i < 20; i++) {
+		char buf[200];
+		(void)fgets(buf, sizeof(buf), fp);
+	}
+
+	// Init the parser
+	uint8_t frame[20];
+	uint16_t rc_values[18];
+	uint16_t num_values;
+	unsigned sbus_frame_drops = 0;
+	unsigned sbus_frame_resets = 0;
+	bool sbus_failsafe;
+	bool sbus_frame_drop;
+	uint16_t max_channels = sizeof(rc_values) / sizeof(rc_values[0]);
+
+	int rate_limiter = 0;
+	unsigned last_drop = 0;
+
+	while (EOF != (ret = fscanf(fp, "%f,%x,,", &f, &x))) {
+
+		ASSERT_GT(ret, 0);
+
+		frame[0] = x;
+		unsigned len = 1;
+
+		// Pipe the data into the parser
+		hrt_abstime now = hrt_absolute_time();
+
+		// if (rate_limiter % byte_offset == 0) {
+		bool result = false;//sbus_parse(now, &frame[0], len, rc_values, &num_values,
+		// 			 &sbus_failsafe, &sbus_frame_drop, &sbus_frame_drops, max_channels);
+
+		if (result) {
+			//warnx("decoded packet");
+		}
+
+		if (last_drop != (sbus_frame_drops + sbus_frame_resets)) {
+			warnx("frame dropped, now #%d", (sbus_frame_drops + sbus_frame_resets));
+			last_drop = sbus_frame_drops + sbus_frame_resets;
+		}
+
+		rate_limiter++;
+	}
+
+	ASSERT_EQ(ret, EOF);
+}