px4-firmware/unittests/dsm_test.cpp

#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;
	bool dsm_11_bit;
	unsigned dsm_frame_drops = 0;
	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
		bool result = dsm_parse(f*1e6, &frame[0], len, rc_values, &num_values,
						&dsm_11_bit, &dsm_frame_drops, max_channels);

		if (result) {
			warnx("decoded packet with %d channels and %s encoding:", num_values, (dsm_11_bit) ? "11 bit" : "10 bit");

			for (unsigned i = 0; i < num_values; i++) {
				printf("chan #%u:\t%d\n", i, (int)rc_values[i]);
			}
		}

		if (last_drop != (dsm_frame_drops)) {
			warnx("frame dropped, now #%d", (dsm_frame_drops));
			last_drop = dsm_frame_drops;
		}

		rate_limiter++;
	}

	ASSERT_EQ(ret, EOF);
}