ghst_telemetry: send battery status

Send battery status (ghst_telemetry). Apply factors to show correct values of volts, amps and mAh. Change ghost protocol code to follow more MISRA C++ guidelines.

src/drivers/rc_input/RCInput.cpp

@@ -654,16 +654,14 @@ void RCInput::Run()
 						_rc_in.input_source = input_rc_s::RC_INPUT_SOURCE_PX4FMU_GHST;
 						fill_rc_in(_raw_rc_count, _raw_rc_values, cycle_timestamp, false, false, 0, ghst_rssi);
 
-						// Enable GHST Telemetry only on the Omnibus, because on Pixhawk (-related) boards
+						// ghst telemetry works on fmu-v5
+						// on other Pixhawk (-related) boards it does not work because
 						// we cannot write to the RC UART
-						// It might work on FMU-v5. Or another option is to use a different UART port
-#ifdef CONFIG_ARCH_BOARD_OMNIBUS_F4SD
 
 						if (!_rc_scan_locked && !_ghst_telemetry) {
 							_ghst_telemetry = new GHSTTelemetry(_rcs_fd);
 						}
 
-#endif /* CONFIG_ARCH_BOARD_OMNIBUS_F4SD */
 
 						_rc_scan_locked = true;
 

src/drivers/rc_input/RCInput.hpp

@@ -41,7 +41,7 @@
 #include <drivers/drv_rc_input.h>
 #include <lib/perf/perf_counter.h>
 #include <lib/rc/crsf.h>
-#include <lib/rc/ghst.h>
+#include <lib/rc/ghst.hpp>
 #include <lib/rc/dsm.h>
 #include <lib/rc/sbus.h>
 #include <lib/rc/st24.h>
@@ -61,7 +61,7 @@
 #include <uORB/topics/vehicle_command.h>
 
 #include "crsf_telemetry.h"
-#include "ghst_telemetry.h"
+#include "ghst_telemetry.hpp"
 
 #ifdef HRT_PPM_CHANNEL
 # include <systemlib/ppm_decode.h>

src/drivers/rc_input/ghst_telemetry.cpp

@@ -40,8 +40,10 @@
  * @author Juraj Ciberlin <jciberlin1@gmail.com>
  */
 
-#include "ghst_telemetry.h"
-#include <lib/rc/ghst.h>
+#include "ghst_telemetry.hpp"
+#include <lib/rc/ghst.hpp>
+
+using time_literals::operator ""_s;
 
 GHSTTelemetry::GHSTTelemetry(int uart_fd) :
 	_uart_fd(uart_fd)
@@ -50,36 +52,44 @@ GHSTTelemetry::GHSTTelemetry(int uart_fd) :
 
 bool GHSTTelemetry::update(const hrt_abstime &now)
 {
-	const int update_rate_hz = 10;
+	bool success = false;
 
-	if (now - _last_update <= 1_s / (update_rate_hz * num_data_types)) {
-		return false;
+	if ((now - _last_update) > (1_s / (UPDATE_RATE_HZ * NUM_DATA_TYPES))) {
+
+		switch (_next_type) {
+		case 0U:
+			success = send_battery_status();
+			break;
+
+		default:
+			success = false;
+			break;
+		}
+
+		_last_update = now;
+		_next_type = (_next_type + 1U) % NUM_DATA_TYPES;
 	}
 
-	bool sent = false;
-
-	switch (_next_type) {
-	case 0:
-		sent = send_battery_status();
-		break;
-	}
-
-	_last_update = now;
-	_next_type = (_next_type + 1) % num_data_types;
-
-	return sent;
+	return success;
 }
 
 bool GHSTTelemetry::send_battery_status()
 {
+	bool success = false;
+	float voltage_in_10mV;
+	float current_in_10mA;
+	float fuel_in_10mAh;
 	battery_status_s battery_status;
 
-	if (!_battery_status_sub.update(&battery_status)) {
-		return false;
+	if (_battery_status_sub.update(&battery_status)) {
+		voltage_in_10mV = battery_status.voltage_filtered_v * FACTOR_VOLTS_TO_10MV;
+		current_in_10mA = battery_status.current_filtered_a * FACTOR_AMPS_TO_10MA;
+		fuel_in_10mAh = battery_status.discharged_mah * FACTOR_MAH_TO_10MAH;
+		success = ghst_send_telemetry_battery_status(_uart_fd,
+				static_cast<uint16_t>(voltage_in_10mV),
+				static_cast<uint16_t>(current_in_10mA),
+				static_cast<uint16_t>(fuel_in_10mAh));
 	}
 
-	uint16_t voltage = battery_status.voltage_filtered_v * 10;
-	uint16_t current = battery_status.current_filtered_a * 10;
-	uint16_t fuel = battery_status.discharged_mah;
-	return ghst_send_telemetry_battery(_uart_fd, voltage, current, fuel);
+	return success;
 }

src/drivers/rc_input/ghst_telemetry.hpp

@@ -46,8 +46,6 @@
 #include <uORB/topics/battery_status.h>
 #include <drivers/drv_hrt.h>
 
-using namespace time_literals;
-
 /**
  * High-level class that handles sending of GHST telemetry data
  */
@@ -58,7 +56,7 @@ public:
 	 * @param uart_fd file descriptor for the UART to use. It is expected to be configured
 	 * already.
 	 */
-	GHSTTelemetry(int uart_fd);
+	explicit GHSTTelemetry(int uart_fd);
 
 	~GHSTTelemetry() = default;
 
@@ -74,10 +72,16 @@ private:
 
 	uORB::Subscription _battery_status_sub{ORB_ID(battery_status)};
 
-	hrt_abstime _last_update{0};
-
-	static constexpr int num_data_types{1}; // number of different telemetry data types
-	int _next_type{0};
-
 	int _uart_fd;
+	hrt_abstime _last_update {0U};
+	uint32_t _next_type {0U};
+
+	static constexpr uint32_t NUM_DATA_TYPES {1U};	// number of different telemetry data types
+	static constexpr uint32_t UPDATE_RATE_HZ {10U};	// update rate [Hz]
+
+	// Factors that should be applied to get correct values
+	static constexpr float FACTOR_VOLTS_TO_10MV {100.0F};
+	static constexpr float FACTOR_AMPS_TO_10MA {100.0F};
+	static constexpr float FACTOR_MAH_TO_10MAH {0.1F};
+
 };

src/lib/rc/common_rc.h

@@ -4,8 +4,8 @@
 #include <stdint.h>
 
 #include "crsf.h"
-#include "ghst.h"
 #include "dsm.h"
+#include "ghst.hpp"
 #include "sbus.h"
 #include "st24.h"
 #include "sumd.h"

src/lib/rc/ghst.cpp

@@ -60,20 +60,19 @@
 // TODO: include RSSI dBm to percentage conversion for ghost receiver
 #include "spektrum_rssi.h"
 
-#include "ghst.h"
+#include "ghst.hpp"
 #include "common_rc.h"
 
 #define MIN(a,b) (((a)<(b))?(a):(b))
-#define MAX(a,b) (((a)>(b))?(a):(b))
 
-#define GHST_FRAME_PAYLOAD_SIZE_TELEMETRY	(10u)
-#define GHST_FRAME_CRC_SIZE			(1)
-#define GHST_FRAME_TYPE_SIZE			(1)
-#define GHST_TYPE_DATA_CRC_SIZE			(12u)
+#define GHST_FRAME_PAYLOAD_SIZE_TELEMETRY	(10U)
+#define GHST_FRAME_CRC_SIZE			(1U)
+#define GHST_FRAME_TYPE_SIZE			(1U)
+#define GHST_TYPE_DATA_CRC_SIZE			(12U)
 #define GHST_MAX_NUM_CHANNELS			(16)
 
 enum class ghst_parser_state_t : uint8_t {
-	unsynced = 0,
+	unsynced = 0U,
 	synced
 };
 
@@ -81,7 +80,7 @@ enum class ghst_parser_state_t : uint8_t {
 static int8_t ghst_rssi = -1;
 
 static ghst_frame_t &ghst_frame = rc_decode_buf.ghst_frame;
-static uint32_t current_frame_position = 0;
+static uint32_t current_frame_position = 0U;
 static ghst_parser_state_t parser_state = ghst_parser_state_t::unsynced;
 
 static uint16_t prev_rc_vals[GHST_MAX_NUM_CHANNELS];
@@ -100,7 +99,7 @@ int ghst_config(int uart_fd)
 	tcgetattr(uart_fd, &t);
 	cfsetspeed(&t, GHST_BAUDRATE);
 	t.c_cflag &= ~(CSTOPB | PARENB);
-	memset(prev_rc_vals, (int)UINT16_MAX, sizeof(uint16_t) * GHST_MAX_NUM_CHANNELS);
+	memset(prev_rc_vals, static_cast<int>(UINT16_MAX), sizeof(uint16_t) * GHST_MAX_NUM_CHANNELS);
 	ret_val = tcsetattr(uart_fd, TCSANOW, &t);
 	return ret_val;
 }
@@ -121,51 +120,51 @@ bool ghst_parse(const uint64_t now, const uint8_t *frame, unsigned len, uint16_t
 
 	memcpy(values, prev_rc_vals, sizeof(uint16_t) * GHST_MAX_NUM_CHANNELS);
 
-	while (len > 0) {
+	while (len > 0U) {
 
 		// fill in the ghst_buffer, as much as we can
-		const unsigned current_len = MIN(len, sizeof(ghst_frame_t) - current_frame_position);
+		const uint32_t current_len = MIN(len, sizeof(ghst_frame_t) - current_frame_position);
 		memcpy(ghst_frame_ptr + current_frame_position, frame, current_len);
 		current_frame_position += current_len;
 
 		// protection to guarantee parsing progress
-		if (current_len == 0) {
-			GHST_DEBUG("========== parser bug: no progress (%i) ===========", len);
+		if (current_len == 0U) {
+			GHST_DEBUG("========== parser bug: no progress (%u) ===========", len);
 
-			for (unsigned i = 0; i < current_frame_position; ++i) {
-				GHST_DEBUG("ghst_frame_ptr[%i]: 0x%x", i, (int)ghst_frame_ptr[i]);
+			for (uint32_t i = 0U; i < current_frame_position; ++i) {
+				GHST_DEBUG("ghst_frame_ptr[%u]: 0x%x", i, ghst_frame_ptr[i]);
 			}
 
 			// reset the parser
-			current_frame_position = 0;
+			current_frame_position = 0U;
 			parser_state = ghst_parser_state_t::unsynced;
-			return false;
-		}
+			success = false;
 
-		len -= current_len;
-		frame += current_len;
+		} else {
+			len -= current_len;
+			frame += current_len;
 
-		if (ghst_parse_buffer(values, rssi, num_values, max_channels)) {
-			success = true;
+			if (ghst_parse_buffer(values, rssi, num_values, max_channels)) {
+				success = true;
+			}
 		}
 	}
 
-
 	return success;
 }
 
 uint8_t ghst_frame_CRC(const ghst_frame_t &frame)
 {
-	uint8_t crc = crc8_dvb_s2(0, frame.type);
+	uint8_t crc = crc8_dvb_s2(0U, frame.type);
 
-	for (int i = 0; i < frame.header.length - GHST_FRAME_CRC_SIZE - GHST_FRAME_TYPE_SIZE; ++i) {
+	for (uint32_t i = 0U; i < frame.header.length - GHST_FRAME_CRC_SIZE - GHST_FRAME_TYPE_SIZE; ++i) {
 		crc = crc8_dvb_s2(crc, frame.payload[i]);
 	}
 
 	return crc;
 }
 
-static uint16_t convert_channel_value(unsigned chan_value)
+static uint16_t convert_channel_value(unsigned int chan_value)
 {
 	/*
 	 *       RC     PWM
@@ -173,9 +172,13 @@ static uint16_t convert_channel_value(unsigned chan_value)
 	 * mid  992 -> 1500us
 	 * max 1811 -> 2012us
 	 */
-	static constexpr float scale = (2012.f - 988.f) / (1811.f - 172.f);
-	static constexpr float offset = 988.f - 172.f * scale;
-	return (scale * chan_value) + offset;
+	static constexpr float scale = (2012.0F - 988.0F) / (1811.0F - 172.0F);
+	static constexpr float offset = 988.0F - (172.0F * scale);
+	float scaled_chan_value = scale * static_cast<float>(chan_value);
+	float scaled_chan_value_with_offset = scaled_chan_value + offset;
+	uint16_t converted_chan_value = static_cast<uint16_t>(scaled_chan_value_with_offset);
+
+	return converted_chan_value;
 }
 
 static bool ghst_parse_buffer(uint16_t *values, int8_t *rssi, uint16_t *num_values, uint16_t max_channels)
@@ -184,16 +187,16 @@ static bool ghst_parse_buffer(uint16_t *values, int8_t *rssi, uint16_t *num_valu
 
 	if (parser_state == ghst_parser_state_t::unsynced) {
 		// there is no sync yet, try to find an RC packet by searching for a matching frame length and type
-		for (unsigned i = 1; i < current_frame_position - 1; ++i) {
-			if ((ghst_frame_ptr[i + 1] >= (uint8_t)ghstFrameType::frameTypeFirst) &&
-			    (ghst_frame_ptr[i + 1] <= (uint8_t)ghstFrameType::frameTypeLast)) {
+		for (uint32_t i = 1U; i < current_frame_position - 1U; ++i) {
+			if ((ghst_frame_ptr[i + 1U] >= static_cast<uint8_t>(ghstFrameType::frameTypeFirst)) &&
+			    (ghst_frame_ptr[i + 1U] <= static_cast<uint8_t>(ghstFrameType::frameTypeLast))) {
 				if (ghst_frame_ptr[i] == GHST_TYPE_DATA_CRC_SIZE) {
 					parser_state = ghst_parser_state_t::synced;
-					unsigned frame_offset = i - 1;
-					GHST_VERBOSE("RC channels found at offset %i", frame_offset);
+					uint32_t frame_offset = i - 1U;
+					GHST_VERBOSE("RC channels found at offset %u", frame_offset);
 
 					// move the rest of the buffer to the beginning
-					if (frame_offset != 0) {
+					if (frame_offset != 0U) {
 						memmove(ghst_frame_ptr, ghst_frame_ptr + frame_offset, current_frame_position - frame_offset);
 						current_frame_position -= frame_offset;
 					}
@@ -207,7 +210,7 @@ static bool ghst_parse_buffer(uint16_t *values, int8_t *rssi, uint16_t *num_valu
 	if (parser_state != ghst_parser_state_t::synced) {
 		if (current_frame_position >= sizeof(ghst_frame_t)) {
 			// discard most of the data, but keep the last 3 bytes (otherwise we could miss the frame start)
-			current_frame_position = 3;
+			current_frame_position = 3U;
 
 			memcpy(ghst_frame_ptr, ghst_frame_ptr + sizeof(ghst_frame_t) - current_frame_position, current_frame_position);
 
@@ -218,7 +221,7 @@ static bool ghst_parse_buffer(uint16_t *values, int8_t *rssi, uint16_t *num_valu
 	}
 
 
-	if (current_frame_position < 3) {
+	if (current_frame_position < 3U) {
 		// wait until we have the address, length and type
 		return false;
 	}
@@ -227,18 +230,18 @@ static bool ghst_parse_buffer(uint16_t *values, int8_t *rssi, uint16_t *num_valu
 
 	const unsigned current_frame_length = ghst_frame.header.length + sizeof(ghst_frame_header_t);
 
-	if (current_frame_length > sizeof(ghst_frame_t) || current_frame_length < 4) {
+	if ((current_frame_length > sizeof(ghst_frame_t)) || (current_frame_length < 4U)) {
 		// frame too long or bogus (frame length should be longer than 4, at least 1 address, 1 length, 1 type, 1 data, 1 crc)
 		// discard everything and go into unsynced state
-		current_frame_position = 0;
+		current_frame_position = 0U;
 		parser_state = ghst_parser_state_t::unsynced;
-		GHST_DEBUG("Frame too long/bogus (%i, type=%i) -> unsync", current_frame_length, ghst_frame.type);
+		GHST_DEBUG("Frame too long/bogus (%u, type=%u) -> unsync", current_frame_length, ghst_frame.type);
 		return false;
 	}
 
 	if (current_frame_position < current_frame_length) {
 		// we do not have the full frame yet -> wait for more data
-		GHST_VERBOSE("waiting for more data (%i < %i)", current_frame_position, current_frame_length);
+		GHST_VERBOSE("waiting for more data (%u < %u)", current_frame_position, current_frame_length);
 		return false;
 	}
 
@@ -246,59 +249,58 @@ static bool ghst_parse_buffer(uint16_t *values, int8_t *rssi, uint16_t *num_valu
 
 	// now we have the full frame
 
-	if ((ghst_frame.type >= (uint8_t)ghstFrameType::frameTypeFirst) &&
-	    (ghst_frame.type <= (uint8_t)ghstFrameType::frameTypeLast) &&
+	if ((ghst_frame.type >= static_cast<uint8_t>(ghstFrameType::frameTypeFirst)) &&
+	    (ghst_frame.type <= static_cast<uint8_t>(ghstFrameType::frameTypeLast)) &&
 	    (ghst_frame.header.length == GHST_TYPE_DATA_CRC_SIZE)) {
-		const uint8_t crc = ghst_frame.payload[ghst_frame.header.length - 2];
+		const uint8_t crc = ghst_frame.payload[ghst_frame.header.length - 2U];
 
 		if (crc == ghst_frame_CRC(ghst_frame)) {
 			const ghstPayloadData_t *const rcChannels = (ghstPayloadData_t *)&ghst_frame.payload;
 			*num_values = MIN(max_channels, GHST_MAX_NUM_CHANNELS);
 
 			// all frames contain data from chan1to4
-			if (max_channels > 0) { values[0] = convert_channel_value(rcChannels->chan1to4.chan1 >> 1); }
+			if (max_channels > 0U) { values[0] = convert_channel_value(rcChannels->chan1to4.chan1 >> 1U); }
 
-			if (max_channels > 1) { values[1] = convert_channel_value(rcChannels->chan1to4.chan2 >> 1); }
+			if (max_channels > 1U) { values[1] = convert_channel_value(rcChannels->chan1to4.chan2 >> 1U); }
 
-			if (max_channels > 2) { values[2] = convert_channel_value(rcChannels->chan1to4.chan3 >> 1); }
+			if (max_channels > 2U) { values[2] = convert_channel_value(rcChannels->chan1to4.chan3 >> 1U); }
 
-			if (max_channels > 3) { values[3] = convert_channel_value(rcChannels->chan1to4.chan4 >> 1); }
+			if (max_channels > 3U) { values[3] = convert_channel_value(rcChannels->chan1to4.chan4 >> 1U); }
 
-			if (ghst_frame.type == (uint8_t)ghstFrameType::frameType5to8) {
-				if (max_channels > 4) { values[4] = convert_channel_value(rcChannels->chanA << 3); }
+			if (ghst_frame.type == static_cast<uint8_t>(ghstFrameType::frameType5to8)) {
+				if (max_channels > 4U) { values[4] = convert_channel_value(rcChannels->chanA << 3U); }
 
-				if (max_channels > 5) { values[5] = convert_channel_value(rcChannels->chanB << 3); }
+				if (max_channels > 5U) { values[5] = convert_channel_value(rcChannels->chanB << 3U); }
 
-				if (max_channels > 6) { values[6] = convert_channel_value(rcChannels->chanC << 3); }
+				if (max_channels > 6U) { values[6] = convert_channel_value(rcChannels->chanC << 3U); }
 
-				if (max_channels > 7) { values[7] = convert_channel_value(rcChannels->chanD << 3); }
+				if (max_channels > 7U) { values[7] = convert_channel_value(rcChannels->chanD << 3U); }
 
-			} else if (ghst_frame.type == (uint8_t)ghstFrameType::frameType9to12) {
-				if (max_channels > 8) { values[8] = convert_channel_value(rcChannels->chanA << 3); }
+			} else if (ghst_frame.type == static_cast<uint8_t>(ghstFrameType::frameType9to12)) {
+				if (max_channels > 8U) { values[8] = convert_channel_value(rcChannels->chanA << 3U); }
 
-				if (max_channels > 9) { values[9] = convert_channel_value(rcChannels->chanB << 3); }
+				if (max_channels > 9U) { values[9] = convert_channel_value(rcChannels->chanB << 3U); }
 
-				if (max_channels > 10) { values[10] = convert_channel_value(rcChannels->chanC << 3); }
+				if (max_channels > 10U) { values[10] = convert_channel_value(rcChannels->chanC << 3U); }
 
-				if (max_channels > 11) { values[11] = convert_channel_value(rcChannels->chanD << 3); }
+				if (max_channels > 11U) { values[11] = convert_channel_value(rcChannels->chanD << 3U); }
 
-			} else if (ghst_frame.type == (uint8_t)ghstFrameType::frameType13to16) {
-				if (max_channels > 12) { values[12] = convert_channel_value(rcChannels->chanA << 3); }
+			} else if (ghst_frame.type == static_cast<uint8_t>(ghstFrameType::frameType13to16)) {
+				if (max_channels > 12U) { values[12] = convert_channel_value(rcChannels->chanA << 3U); }
 
-				if (max_channels > 13) { values[13] = convert_channel_value(rcChannels->chanB << 3); }
+				if (max_channels > 13U) { values[13] = convert_channel_value(rcChannels->chanB << 3U); }
 
-				if (max_channels > 14) { values[14] = convert_channel_value(rcChannels->chanC << 3); }
+				if (max_channels > 14U) { values[14] = convert_channel_value(rcChannels->chanC << 3U); }
 
-				if (max_channels > 15) { values[15] = convert_channel_value(rcChannels->chanD << 3); }
+				if (max_channels > 15U) { values[15] = convert_channel_value(rcChannels->chanD << 3U); }
 
-			} else if (ghst_frame.type == (uint8_t)ghstFrameType::frameTypeRssi) {
+			} else if (ghst_frame.type == static_cast<uint8_t>(ghstFrameType::frameTypeRssi)) {
 				const ghstPayloadRssi_t *const rssiValues = (ghstPayloadRssi_t *)&ghst_frame.payload;
 				// TODO: call function for RSSI dBm to percentage conversion for ghost receiver
-				ghst_rssi = spek_dbm_to_percent(rssiValues->rssidBm);
-			}
+				ghst_rssi = spek_dbm_to_percent(static_cast<int8_t>(rssiValues->rssidBm));
 
-			else {
-				GHST_DEBUG("Frame type: %i", ghst_frame.type);
+			} else {
+				GHST_DEBUG("Frame type: %u", ghst_frame.type);
 			}
 
 			*rssi = ghst_rssi;
@@ -314,17 +316,17 @@ static bool ghst_parse_buffer(uint16_t *values, int8_t *rssi, uint16_t *num_valu
 		}
 
 	} else {
-		GHST_DEBUG("Got Non-RC frame (len=%i, type=%i)", current_frame_length, ghst_frame.type);
+		GHST_DEBUG("Got Non-RC frame (len=%u, type=%u)", current_frame_length, ghst_frame.type);
 	}
 
 	// either reset or move the rest of the buffer
 	if (current_frame_position > current_frame_length) {
-		GHST_VERBOSE("Moving buffer (%i > %i)", current_frame_position, current_frame_length);
+		GHST_VERBOSE("Moving buffer (%u > %u)", current_frame_position, current_frame_length);
 		memmove(ghst_frame_ptr, ghst_frame_ptr + current_frame_length, current_frame_position - current_frame_length);
 		current_frame_position -= current_frame_length;
 
 	} else {
-		current_frame_position = 0;
+		current_frame_position = 0U;
 	}
 
 	return ret;
@@ -343,8 +345,8 @@ static inline void write_uint8_t(uint8_t *buf, int &offset, uint8_t value)
  */
 static inline void write_uint16_t(uint8_t *buf, int &offset, uint16_t value)
 {
-	buf[offset] = value & 0xff;
-	buf[offset + 1] = value >> 8;
+	buf[offset] = value & 0xFFU;
+	buf[offset + 1] = value >> 8U;
 	offset += 2;
 }
 
@@ -353,9 +355,9 @@ static inline void write_uint16_t(uint8_t *buf, int &offset, uint16_t value)
  */
 static inline void write_frame_header(uint8_t *buf, int &offset, ghstTelemetryType type, uint8_t payload_size)
 {
-	write_uint8_t(buf, offset, (uint8_t)ghstAddress::rxAddress);
+	write_uint8_t(buf, offset, static_cast<uint8_t>(ghstAddress::rxAddress));
 	write_uint8_t(buf, offset, payload_size + GHST_FRAME_CRC_SIZE + GHST_FRAME_TYPE_SIZE);
-	write_uint8_t(buf, offset, (uint8_t)type);
+	write_uint8_t(buf, offset, static_cast<uint8_t>(type));
 }
 
 /**
@@ -363,21 +365,31 @@ static inline void write_frame_header(uint8_t *buf, int &offset, ghstTelemetryTy
  */
 static inline void write_frame_crc(uint8_t *buf, int &offset, int buf_size)
 {
-	write_uint8_t(buf, offset, crc8_dvb_s2_buf(buf + 2, buf_size - 3));
+	write_uint8_t(buf, offset, crc8_dvb_s2_buf(buf + 2U, buf_size - 3));
 }
 
-bool ghst_send_telemetry_battery(int uart_fd, uint16_t voltage, uint16_t current, uint16_t fuel)
+bool ghst_send_telemetry_battery_status(int uart_fd, uint16_t voltage_in_10mV,
+					uint16_t current_in_10mA, uint16_t fuel_in_10mAh)
 {
-	uint8_t buf[GHST_FRAME_PAYLOAD_SIZE_TELEMETRY + 4u]; // address, frame length, type, crc
+	bool success;
+	uint8_t buf[GHST_FRAME_PAYLOAD_SIZE_TELEMETRY + 4U]; // address, frame length, type, crc
 	int offset = 0;
 	write_frame_header(buf, offset, ghstTelemetryType::batteryPack, GHST_FRAME_PAYLOAD_SIZE_TELEMETRY);
-	write_uint16_t(buf, offset, voltage);
-	write_uint16_t(buf, offset, current);
-	write_uint16_t(buf, offset, fuel);
-	write_uint8_t(buf, offset, 0x00); // empty
-	write_uint8_t(buf, offset, 0x00); // empty
-	write_uint8_t(buf, offset, 0x00); // empty
-	write_uint8_t(buf, offset, 0x00); // empty
+	write_uint16_t(buf, offset, voltage_in_10mV);
+	write_uint16_t(buf, offset, current_in_10mA);
+	write_uint16_t(buf, offset, fuel_in_10mAh);
+	write_uint8_t(buf, offset, 0x00U); // empty
+	write_uint8_t(buf, offset, 0x00U); // empty
+	write_uint8_t(buf, offset, 0x00U); // empty
+	write_uint8_t(buf, offset, 0x00U); // empty
 	write_frame_crc(buf, offset, sizeof(buf));
-	return write(uart_fd, buf, offset) == offset;
+
+	if (write(uart_fd, buf, offset) == offset) {
+		success = true;
+
+	} else {
+		success = false;
+	}
+
+	return success;
 }

src/lib/rc/ghst.hpp

@@ -68,14 +68,14 @@ enum class ghstTelemetryType {
 };
 
 struct ghst_frame_header_t {
-	uint8_t device_address;				// device address
-	uint8_t length;					// length
+	uint8_t device_address;			// device address
+	uint8_t length;				// length
 };
 
 struct ghst_frame_t {
 	ghst_frame_header_t header;			// header
 	uint8_t type;					// frame type
-	uint8_t payload[GHST_PAYLOAD_MAX_SIZE + 1];	// payload data including 1 byte CRC at the end
+	uint8_t payload[GHST_PAYLOAD_MAX_SIZE + 1U];	// payload data including 1 byte CRC at the end
 };
 
 // Channel data (1-4)
@@ -131,11 +131,12 @@ __EXPORT bool ghst_parse(const uint64_t now, const uint8_t *frame, unsigned len,
 /**
  * Send telemetry battery information
  * @param uart_fd UART file descriptor
- * @param voltage Voltage [0.1V]
- * @param current Current [0.1A]
- * @param fuel drawn mAh
+ * @param voltage_in_10mV Voltage [10 mV]
+ * @param current_in_10mA Current [10 mA]
+ * @param fuel_in_10mAh Fuel [10 mAh]
  * @return true on success
  */
-__EXPORT bool ghst_send_telemetry_battery(int uart_fd, uint16_t voltage, uint16_t current, uint16_t fuel);
+__EXPORT bool ghst_send_telemetry_battery_status(int uart_fd, uint16_t voltage_in_10mV,
+		uint16_t current_in_10mA, uint16_t fuel_in_10mAh);
 
 __END_DECLS

src/lib/rc/rc_tests/RCTest.cpp

@@ -14,7 +14,7 @@
 #include <lib/rc/st24.h>
 #include <lib/rc/sumd.h>
 #include <lib/rc/crsf.h>
-#include <lib/rc/ghst.h>
+#include <lib/rc/ghst.hpp>
 
 #if defined(CONFIG_ARCH_BOARD_PX4_SITL)
 #define TEST_DATA_PATH "./test_data/"