...update from dev (#10)

* ...just some ideas

* ...adding return values

...prepare for proper debug

* ...compare signals

...some signal captures

DShotRMT.cpp

@@ -9,7 +9,8 @@
 #include "DShotRMT.h"
 
 // --- DShot Timings ---
-const dshot_timing_t DSHOT_TIMINGS[] = {
+// frame_length_us, ticks_per_bit, ticks_one_high, ticks_zero_high, ticks_zero_low, ticks_one_low
+constexpr dshot_timing_t DSHOT_TIMINGS[] = {
     {0, 0, 0, 0, 0, 0},        // DSHOT_OFF
     {128, 64, 48, 24, 40, 16}, // DSHOT150
     {64, 32, 24, 12, 20, 8},   // DSHOT300
@@ -18,15 +19,16 @@ const dshot_timing_t DSHOT_TIMINGS[] = {
 };
 
 //
-DShotRMT::DShotRMT(gpio_num_t gpio, dshot_mode_t mode, bool is_bidirectional)
-    : _gpio(gpio), _mode(mode)
-    , _is_bidirectional(is_bidirectional)
-    , _timing_config(DSHOT_TIMINGS[mode])
-    , _rmt_tx_channel(nullptr)
-    , _rmt_rx_channel(nullptr)
-    , _dshot_encoder(nullptr)
-    , _last_erpm(0)
-    , _last_transmission_time(0)
+DShotRMT::DShotRMT(gpio_num_t gpio, dshot_mode_t mode, bool is_bidirectional):
+     _gpio(gpio),
+     _mode(mode),
+     _is_bidirectional(is_bidirectional),
+     _timing_config(DSHOT_TIMINGS[mode]),
+     _rmt_tx_channel(nullptr),
+     _rmt_rx_channel(nullptr),
+     _dshot_encoder(nullptr),
+     _last_erpm(0),
+     _last_transmission_time(0)
 {
     // Calculate frame time including switch time
     _frame_time_us = _timing_config.frame_length_us + DSHOT_SWITCH_TIME;
@@ -38,21 +40,24 @@ DShotRMT::DShotRMT(gpio_num_t gpio, dshot_mode_t mode, bool is_bidirectional)
     }
 }
 
-//
+// Init DShotRMT
 bool DShotRMT::begin()
 {
+    // Init TX Channel
     if (!_initTXChannel())
     {
         Serial.println("Failed to initialize TX channel");
         return DSHOT_ERROR;
     }
 
+    // Init RX Channel
     if (!_initRXChannel() && _is_bidirectional)
     {
         Serial.println("Failed to initialize RX channel");
         return DSHOT_ERROR;
     }
 
+    // Init DShot Decoder
     if (!_initDShotEncoder())
     {
         Serial.println("Failed to initialize encoder");
@@ -65,7 +70,6 @@ bool DShotRMT::begin()
 //
 bool DShotRMT::setThrottle(uint16_t throttle)
 {
-
     // DShot Frame Container
     dshot_packet_t packet = {};
 
@@ -78,6 +82,26 @@ bool DShotRMT::setThrottle(uint16_t throttle)
     {
         return DSHOT_ERROR;
     }
+
+    return DSHOT_OK;
+}
+
+//
+bool DShotRMT::sendDShotCommand(uint16_t command)
+{
+    // DShot Frame Container
+    dshot_packet_t packet = {};
+
+    // Create DShot packet
+    packet.throttle_value = constrain(command, DSHOT_CMD_MOTOR_STOP, DSHOT_CMD_MAX);
+    packet.telemetric_request = _is_bidirectional;
+    packet.checksum = _calculateCRC(packet);
+
+    if (!_sendDShotFrame(packet))
+    {
+        return DSHOT_ERROR;
+    }
+    return DSHOT_OK;
 }
 
 //
@@ -164,28 +188,30 @@ bool DShotRMT::_initDShotEncoder()
     return rmt_new_copy_encoder(&encoder_config, &_dshot_encoder) == 0;
 }
 
-//
-bool DShotRMT::_sendDShotFrame(const dshot_packet_t &packet)
+// Use RMT to transmit a prepared DShot packet and returns it
+uint16_t DShotRMT::_sendDShotFrame(const dshot_packet_t &packet)
 {
-    //
-    if (!_timer_signal())
-    {
-        return DSHOT_ERROR;
-    }
-
     // Encodes packet directly into RMT Buffer
     rmt_symbol_word_t tx_symbols[DSHOT_BITS_PER_FRAME];
     _encodeDShotFrame(packet, tx_symbols);
 
+    //
+    if (!_timer_signal())
+    {
+        return DSHOT_NULL_PACKET;
+    }
+
     // Trigger RMT Transmit
     if (rmt_transmit(_rmt_tx_channel, _dshot_encoder, tx_symbols, DSHOT_SYMBOLS_SIZE, &_transmit_config) != 0)
     {
         Serial.println("Failed to transmit DShot packet");
-        return DSHOT_ERROR;
+        return DSHOT_NULL_PACKET;
     }
 
+    // Time Stamp
     _timer_reset();
-    return DSHOT_OK;
+
+    return _assembleDShotFrame(packet);
 }
 
 //
@@ -212,8 +238,7 @@ uint16_t DShotRMT::_assembleDShotFrame(const dshot_packet_t &packet)
 }
 
 //
-void DShotRMT::_encodeDShotFrame(const dshot_packet_t &packet, rmt_symbol_word_t *symbols)
-{
+bool DShotRMT::_encodeDShotFrame(const dshot_packet_t& packet, rmt_symbol_word_t* symbols)
 {
     // Encoding to "raw" DShot Packet
     uint16_t frame_bits = _assembleDShotFrame(packet);
@@ -238,7 +263,7 @@ void DShotRMT::_encodeDShotFrame(const dshot_packet_t &packet, rmt_symbol_word_t
             symbols[i].duration1 = bit ? _timing_config.ticks_one_low : _timing_config.ticks_zero_low;
         }
     }
-    }
+    return DSHOT_OK;
 }
 
 //
@@ -282,7 +307,9 @@ bool DShotRMT::_timer_signal()
 }
 
 //
-void DShotRMT::_timer_reset()
+bool DShotRMT::_timer_reset()
 {
+    // Timestamp update
     _last_transmission_time = micros();
+    return DSHOT_OK;
 }

DShotRMT.h

@@ -13,6 +13,7 @@
 #include <driver/gpio.h>
 #include <driver/rmt_tx.h>
 #include <driver/rmt_rx.h>
+#include <hw_defaults.h>
 
 static constexpr bool DSHOT_OK = 0;
 static constexpr bool DSHOT_ERROR = 1;
@@ -23,7 +24,7 @@ static constexpr uint16_t DSHOT_THROTTLE_MIN = 48;
 static constexpr uint16_t DSHOT_THROTTLE_MAX = 2047;
 
 static constexpr uint8_t DSHOT_BITS_PER_FRAME = 16;
-static constexpr uint8_t DSHOT_SWITCH_TIME = 21;
+static constexpr uint8_t DSHOT_SWITCH_TIME = 300; // 30us
 static constexpr uint16_t DSHOT_NULL_PACKET = 0b0000000000000000;
 
 // --- RMT Config Constants ---
@@ -65,6 +66,7 @@ typedef struct
 // --- DShot Timing Config ---
 extern const dshot_timing_t DSHOT_TIMINGS[];
 
+//
 class DShotRMT
 {
 public:
@@ -122,12 +124,12 @@ private:
     bool _initRXChannel();
     bool _initDShotEncoder();
 
+    uint16_t _sendDShotFrame(const dshot_packet_t &packet);
     uint16_t _calculateCRC(const dshot_packet_t &packet);
     uint16_t _assembleDShotFrame(const dshot_packet_t &packet);
-    void _encodeDShotFrame(const dshot_packet_t &packet, rmt_symbol_word_t *symbols);
+    bool _encodeDShotFrame(const dshot_packet_t &packet, rmt_symbol_word_t *symbols);
     uint16_t _decodeDShotFrame(const rmt_symbol_word_t *symbols, size_t symbol_count);
-    bool _sendDShotFrame(const dshot_packet_t &packet);
 
     bool _timer_signal();
-    void _timer_reset();
+    bool _timer_reset();
 };

examples/dshot300/dshot300.ino

@@ -10,18 +10,18 @@
 #include <DShotRMT.h>
 
 // USB serial port settings
-constexpr auto &USB_SERIAL = Serial0;
-constexpr uint32_t USB_SERIAL_BAUD = 115200;
+static constexpr HardwareSerial &USB_SERIAL = Serial0;
+static constexpr uint32_t USB_SERIAL_BAUD = 115200;
 
 // Motor configuration
-constexpr gpio_num_t MOTOR01_PIN = GPIO_NUM_17;
-constexpr dshot_mode_t DSHOT_MODE = DSHOT300;
+static constexpr gpio_num_t MOTOR01_PIN = GPIO_NUM_17;
+static constexpr dshot_mode_t DSHOT_MODE = DSHOT300;
 
 // BiDirectional DShot Support (default: false)
-constexpr bool IS_BIDIRECTIONAL = false;
+static constexpr bool IS_BIDIRECTIONAL = false;
 
 // Motor magnet count for RPM calculation
-constexpr uint8_t MOTOR01_MAGNET_COUNT = 14;
+static constexpr uint8_t MOTOR01_MAGNET_COUNT = 14;
 
 // Setup Motor Pin, DShot Mode and optional BiDirectional Support
 DShotRMT motor01(MOTOR01_PIN, DSHOT_MODE, IS_BIDIRECTIONAL);

hw_defaults.h

@@ -0,0 +1,36 @@
+/**
+ * @file hw_defaults.h
+ * @brief Some Shortcuts
+ * @author Wastl Kraus
+ * @date 2025-08-02
+ * @license MIT
+ */
+
+#ifdef ESP32
+// USB-Serial (UART0): GPIO1/3 in use by default
+
+// Serial1
+constexpr auto PIN_UART1_TX = GPIO_NUM_13;
+constexpr auto PIN_UART1_RX = GPIO_NUM_14;
+
+// Serial2
+constexpr auto PIN_UART2_TX = GPIO_NUM_16;
+constexpr auto PIN_UART2_RX = GPIO_NUM_17;
+
+// SPI (VSPI)
+constexpr auto PIN_SPI_SCLK = GPIO_NUM_18;
+constexpr auto PIN_SPI_MISO = GPIO_NUM_19;
+constexpr auto PIN_SPI_MOSI = GPIO_NUM_23;
+constexpr auto PIN_SPI_SS = GPIO_NUM_5;
+
+// I2C (Wire)
+constexpr auto PIN_I2C_SDA = GPIO_NUM_21;
+constexpr auto PIN_I2C_SCL = GPIO_NUM_22;
+
+// RMT (5 Channels)
+constexpr auto PIN_RMT_CH0 = GPIO_NUM_25;
+constexpr auto PIN_RMT_CH1 = GPIO_NUM_26;
+constexpr auto PIN_RMT_CH2 = GPIO_NUM_27;
+constexpr auto PIN_RMT_CH3 = GPIO_NUM_32;
+constexpr auto PIN_RMT_CH4 = GPIO_NUM_33;
+#endif // ESP32