dshot: breakout driver header file, use static_casts, add const specifiers (#15908)

* Break out dshot.h from dshot.cpp and rename files to reflect the class name. Move DShot class specific #defines from drv_pwm_output.h to dshot.h. Replace c-style casts with static_casts, standardize method naming, single line comment styles, and formatting. Rename update_dshot_out_state() to enable_dshot_outputs().
2026-11-12 19:41:36 +08:00 · 2020-12-09 08:51:47 +01:00
parent cf010f44d0
commit dd4ee5c48c
6 changed files with 401 additions and 385 deletions
@@ -0,0 +1,143 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+#include <drivers/drv_hrt.h>
+
+class DShotTelemetry
+{
+public:
+	struct EscData {
+		hrt_abstime time;
+		int8_t temperature;  ///< [deg C]
+		int16_t voltage;     ///< [0.01V]
+		int16_t current;     ///< [0.01A]
+		int16_t consumption; ///< [mAh]
+		int16_t erpm;        ///< [100ERPM]
+	};
+
+	static constexpr int esc_info_size_blheli32 = 64;
+	static constexpr int esc_info_size_kiss_v1 = 15;
+	static constexpr int esc_info_size_kiss_v2 = 21;
+	static constexpr int max_esc_info_size = esc_info_size_blheli32;
+
+	struct OutputBuffer {
+		uint8_t buffer[max_esc_info_size];
+		int buf_pos{0};
+		int motor_index;
+	};
+
+	~DShotTelemetry();
+
+	int init(const char *uart_device);
+
+	void deinit();
+
+	void setNumMotors(int num_motors) { _num_motors = num_motors; }
+	int numMotors() const { return _num_motors; }
+
+	/**
+	 * Read telemetry from the UART (non-blocking) and handle timeouts.
+	 * @return -1 if no update, -2 timeout, >= 0 for the motor index. Use @latestESCData() to get the data.
+	 */
+	int update();
+
+	/**
+	 * Redirect everything that is read into a different buffer.
+	 * Future calls to @update will write to that instead of an internal buffer, until @update returns
+	 * a value different from -1. No decoding is done.
+	 * The caller must ensure the buffer exists until that point.
+	 * @param buffer
+	 * @return 0 on success <0 on error
+	 */
+	int redirectOutput(OutputBuffer &buffer);
+
+	bool redirectActive() const { return _redirect_output != nullptr; }
+
+	/**
+	 * Get the motor index for which telemetry should be requested.
+	 * @return -1 if no request should be made, motor index otherwise
+	 */
+	int getRequestMotorIndex();
+
+	const EscData &latestESCData() const { return _latest_data; }
+
+	/**
+	 * Check whether we are currently expecting to read new data from an ESC
+	 */
+	bool expectingData() const { return _current_request_start != 0; }
+
+	void printStatus() const;
+
+	static void decodeAndPrintEscInfoPacket(const OutputBuffer &buffer);
+
+private:
+	static constexpr int ESC_FRAME_SIZE = 10;
+
+	/**
+	 * set the Baudrate
+	 * @param baud
+	 * @return 0 on success, <0 on error
+	 */
+	int setBaudrate(unsigned baud);
+
+	void requestNextMotor();
+
+	/**
+	 * Decode a single byte from an ESC feedback frame
+	 * @param byte
+	 * @param successful_decoding set to true if checksum matches
+	 * @return true if received the expected amount of bytes and the next motor can be requested
+	 */
+	bool decodeByte(uint8_t byte, bool &successful_decoding);
+
+	static inline uint8_t updateCrc8(uint8_t crc, uint8_t crc_seed);
+	static uint8_t crc8(const uint8_t *buf, uint8_t len);
+
+	int _uart_fd{-1};
+	int _num_motors{0};
+	uint8_t _frame_buffer[ESC_FRAME_SIZE];
+	int _frame_position{0};
+
+	EscData _latest_data;
+
+	int _current_motor_index_request{-1};
+	hrt_abstime _current_request_start{0};
+
+	OutputBuffer *_redirect_output{nullptr}; ///< if set, all read bytes are stored here instead of the internal buffer
+
+	// statistics
+	int _num_timeouts{0};
+	int _num_successful_responses{0};
+};