134 lines
3.5 KiB
C++
134 lines
3.5 KiB
C++
/**
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* @file DShotRMT.h
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* @brief DShot signal generation using ESP32 RMT with bidirectional support
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* @author Wastl Kraus
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* @date 2025-06-11
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* @license MIT
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*/
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#pragma once
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#include <Arduino.h>
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#include <dshot_commands.h>
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#include <driver/gpio.h>
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#include <driver/rmt_tx.h>
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#include <driver/rmt_rx.h>
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static constexpr bool DSHOT_OK = 0;
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static constexpr bool DSHOT_ERROR = 1;
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// --- DShot Protocol Constants ---
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static constexpr uint16_t DSHOT_THROTTLE_FAILSAFE = 0;
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static constexpr uint16_t DSHOT_THROTTLE_MIN = 48;
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static constexpr uint16_t DSHOT_THROTTLE_MAX = 2047;
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static constexpr uint8_t DSHOT_BITS_PER_FRAME = 16;
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static constexpr uint8_t DSHOT_SWITCH_TIME = 21;
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static constexpr uint16_t DSHOT_NULL_PACKET = 0b0000000000000000;
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// --- RMT Config Constants ---
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static constexpr rmt_clock_source_t DSHOT_CLOCK_SRC_DEFAULT = RMT_CLK_SRC_DEFAULT;
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static constexpr uint32_t DSHOT_RMT_RESOLUTION = 10 * 1000 * 1000; // 10 MHz
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static constexpr size_t TX_BUFFER_SIZE = DSHOT_BITS_PER_FRAME;
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static constexpr size_t RX_BUFFER_SIZE = 32;
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static constexpr size_t DSHOT_SYMBOLS_SIZE = 64;
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// --- DShot Mode Select ---
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typedef enum
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{
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DSHOT_OFF,
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DSHOT150,
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DSHOT300,
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DSHOT600,
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DSHOT1200
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} dshot_mode_t;
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// --- DShot Packet Structure ---
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typedef struct
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{
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uint16_t throttle_value : 11;
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bool telemetric_request : 1;
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uint16_t checksum : 4;
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} dshot_packet_t;
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// --- DShot Timing Config ---
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typedef struct
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{
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uint16_t frame_length_us;
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uint16_t ticks_per_bit;
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uint16_t ticks_one_high;
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uint16_t ticks_zero_high;
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uint16_t ticks_zero_low;
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uint16_t ticks_one_low;
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} dshot_timing_t;
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// --- DShot Timing Config ---
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extern const dshot_timing_t DSHOT_TIMINGS[];
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class DShotRMT
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{
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public:
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//
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DShotRMT(gpio_num_t gpio, dshot_mode_t mode = DSHOT300, bool is_bidirectional = false);
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// --- Init RMT Module ---
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bool begin();
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// Sets the throttle value and transmits
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bool setThrottle(uint16_t throttle);
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// Sends a valid DShot Command
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bool sendDShotCommand(uint16_t command);
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// Gets eRPM from ESC telemetry
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uint32_t getERPM();
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// Converts eRPM to motor RPM
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uint32_t getMotorRPM(uint8_t magnet_count);
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//
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gpio_num_t getGPIO() const { return _gpio; }
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dshot_mode_t getDShotMode() const { return _mode; }
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bool isBidirectional() const { return _is_bidirectional; }
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private:
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// --- Config ---
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gpio_num_t _gpio;
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dshot_mode_t _mode;
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bool _is_bidirectional;
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uint32_t _frame_time_us;
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// --- DShot Timings ---
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const dshot_timing_t &_timing_config;
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// --- RMT Handles ---
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rmt_channel_handle_t _rmt_tx_channel;
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rmt_channel_handle_t _rmt_rx_channel;
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rmt_encoder_handle_t _dshot_encoder;
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// --- RMT Config ---
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rmt_tx_channel_config_t _tx_channel_config;
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rmt_rx_channel_config_t _rx_channel_config;
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rmt_transmit_config_t _transmit_config;
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rmt_receive_config_t _receive_config;
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// --- Buffers ---
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rmt_symbol_word_t _rx_symbols[RX_BUFFER_SIZE];
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uint16_t _last_erpm;
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unsigned long _last_transmission_time;
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//
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bool _initTXChannel();
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bool _initRXChannel();
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bool _initDShotEncoder();
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uint16_t _calculateCRC(const dshot_packet_t &packet);
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uint16_t _assembleDShotFrame(const dshot_packet_t &packet);
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bool _encodeDShotFrame(const dshot_packet_t &packet, rmt_symbol_word_t *symbols);
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uint16_t _decodeDShotFrame(const rmt_symbol_word_t *symbols, size_t symbol_count);
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bool _sendDShotFrame(const dshot_packet_t &packet);
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bool _timer_signal();
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void _timer_reset();
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};
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