re-enabled bidirectional support

README.md

@@ -6,6 +6,8 @@
 
 An Arduino IDE library for generating DShot signals on ESP32 microcontrollers using the **modern ESP-IDF 5 RMT Encoder API** (`rmt_tx.h` / `rmt_rx.h`). This library specifically leverages the official `rmt_bytes_encoder` API for an efficient, hardware-timed and maintainable implementation. It provides a simple way to control BLHeli ESCs in both Arduino and ESP-IDF projects.
 
+### Bidirectional DShot re-enabled for testing.
+
  The legacy version using the old `rmt.h` API is available in the `oldAPI` branch.
 
 ---

examples/dshot300/dshot300.ino

@@ -6,7 +6,6 @@
  * @license MIT
  */
 
-#include <Arduino.h>
 #include <DShotRMT.h>
 
 // USB serial port settings
@@ -15,18 +14,17 @@ static constexpr auto USB_SERIAL_BAUD = 115200;
 
 // Motor configuration - Pin number or GPIO_PIN
 static constexpr gpio_num_t MOTOR01_PIN = GPIO_NUM_27;
-// static constexpr auto MOTOR01_PIN = 17;
+// static constexpr auto MOTOR01_PIN = 27;
 
 // Supported: DSHOT150, DSHOT300, DSHOT600, (DSHOT1200)
 static constexpr dshot_mode_t DSHOT_MODE = DSHOT300;
 
 // BiDirectional DShot Support (default: false)
-// Note: Bidirectional DShot is currently not officially supported
+// re-enabled for testing
-// due to instability and external hardware requirements.
+static constexpr auto IS_BIDIRECTIONAL = false;
-static constexpr auto IS_BIDIRECTIONAL = true;
 
 // Motor magnet count for RPM calculation
-static constexpr auto MOTOR01_MAGNET_COUNT = 14;
+// static constexpr auto MOTOR01_MAGNET_COUNT = 14;
 
 // Creates the motor instance
 DShotRMT motor01(MOTOR01_PIN, DSHOT_MODE, IS_BIDIRECTIONAL);

library.properties

@@ -1,10 +1,10 @@
 name=DShotRMT
-version=0.9.0
+version=0.9.1
 author=Wastl Kraus <wir-sind-die-matrix.de>
 maintainer=Wastl Kraus <wir-sind-die-matrix.de>
 license=MIT
-sentence=DShotRMT Library supporting all DShot Types and speeds. Tested with BlHeli_S.
+sentence=DShotRMT Library supporting all DShot Types and speeds. Bidirectional support re-enabled. Tested with BlHeli_S.
-paragraph=This library can control a BlHeli_S by using encoded DShot commands.
+paragraph=This library can control a BlHeli_S by using encoded DShot commands. Bidirectional support re-enabled.
 category=Signal Input/Output
 url=https://github.com/derdoktor667/DShotRMT
 architectures=esp32

src/DShotRMT.cpp

@@ -119,7 +119,7 @@ dshot_result_t DShotRMT::sendThrottlePercent(float percent)
 dshot_result_t DShotRMT::sendCommand(uint16_t command_value)
 {
     // Validate the integer command value before casting
-    if (command_value < DSHOT_CMD_MOTOR_STOP || command_value > DSHOT_CMD_MAX)
+    if (command_value < DSHOT_CMD_MOTOR_STOP || command_value > DSHOT_CMD_MAX_VALUE)
     {
         return {false, DSHOT_COMMAND_NOT_VALID};
     }
@@ -134,6 +134,7 @@ dshot_result_t DShotRMT::sendCommand(dshotCommands_e command)
 
     switch (command)
     {
+    case DSHOT_CMD_MOTOR_STOP:
     case DSHOT_CMD_SAVE_SETTINGS:
     case DSHOT_CMD_SPIN_DIRECTION_NORMAL:
     case DSHOT_CMD_SPIN_DIRECTION_REVERSED:
@@ -332,6 +333,24 @@ dshot_result_t DShotRMT::_sendDShotFrame(const dshot_packet_t &packet)
         return {true, DSHOT_NONE};
     }
 
+    if (_is_bidirectional)
+    {
+        // Start the receiver to wait for incoming telemetry data
+        rmt_symbol_word_t rx_symbols[GCR_BITS_PER_FRAME];
+        size_t rx_size_bytes = GCR_BITS_PER_FRAME * sizeof(rmt_symbol_word_t);
+
+        rmt_receive_config_t rmt_rx_config = {
+            .signal_range_min_ns = DSHOT_PULSE_MIN_NS,
+            .signal_range_max_ns = DSHOT_PULSE_MAX_NS,
+        };
+
+        if (rmt_receive(_rmt_rx_channel, rx_symbols, rx_size_bytes, &rmt_rx_config) != DSHOT_OK)
+        {
+            return {false, DSHOT_RECEIVER_FAILED};
+        }
+    }
+
+    // Now let's prepare the actual frame
     _encoded_frame_value = _buildDShotFrameValue(packet);
 
     // Byte-swap the 16-bit value for correct transmission order (ESP32 is little-endian, DShot is MSB first)
@@ -342,20 +361,37 @@ dshot_result_t DShotRMT::_sendDShotFrame(const dshot_packet_t &packet)
 
     rmt_transmit_config_t tx_config = {}; // Initialize all members to zero
     tx_config.loop_count = 0;             // No automatic loops - real-time calculation
-    tx_config.flags.eot_level = _is_bidirectional ? 1 : 0;
+
+    // TODO: Find out, why this is needed
+    if (_is_bidirectional)
+    {
+        // Disable RMT RX for sending
+        if (rmt_disable(_rmt_rx_channel) != DSHOT_OK)
+        {
+            return {false, DSHOT_RECEIVER_FAILED};
+        }
+    }
 
     if (rmt_transmit(_rmt_tx_channel, _dshot_encoder, &swapped_value, tx_size_bytes, &tx_config) != DSHOT_OK)
     {
         return {false, DSHOT_TRANSMISSION_FAILED};
     }
 
+    // Re-enable RMT RX
+    if (_is_bidirectional)
+    {
+        if (rmt_enable(_rmt_rx_channel) != DSHOT_OK)
+        {
+            return {false, DSHOT_RECEIVER_FAILED};
+        }
+    }
+
     _recordFrameTransmissionTime(); // Reset the timer for the next frame
 
     return {true, DSHOT_TRANSMISSION_SUCCESS};
 }
 
 // This function needs to be fast, as it generates the RMT symbols just before sending
-
 // Placed in IRAM for high performance, as it's called from an ISR context.
 uint16_t IRAM_ATTR DShotRMT::_decodeDShotFrame(const rmt_symbol_word_t *symbols) const
 {

src/dshot_definitions.h

@@ -127,7 +127,8 @@ enum dshotCommands_e
     DSHOT_CMD_LED2_OFF,
     DSHOT_CMD_LED3_OFF,
     DSHOT_CMD_AUDIO_STREAM_MODE_ON_OFF = 30,
-    DSHOT_CMD_SILENT_MODE_ON_OFF = 31
+    DSHOT_CMD_SILENT_MODE_ON_OFF = 31,
+    DSHOT_CMD_MAX_VALUE = 47
 };
 
 // Custom status codes

src/dshot_init.cpp

@@ -17,11 +17,12 @@ dshot_result_t init_rmt_tx_channel(gpio_num_t gpio, rmt_channel_handle_t *out_ch
         .resolution_hz = DSHOT_RMT_RESOLUTION,
         .mem_block_symbols = RMT_BUFFER_SYMBOLS,
         .trans_queue_depth = RMT_QUEUE_DEPTH,
-    };
+        .flags = {
+            .invert_out = is_bidirectional ? 1 : 0,
+            .init_level = is_bidirectional ? 0 : 1}};
 
     rmt_transmit_config_t rmt_tx_config = {}; // Initialize all members to zero
     rmt_tx_config.loop_count = 0;             // No automatic loops - real-time calculation
-    rmt_tx_config.flags.eot_level = is_bidirectional ? 1 : 0;
 
     if (rmt_new_tx_channel(&tx_channel_config, out_channel) != DSHOT_OK)
     {
@@ -61,20 +62,6 @@ dshot_result_t init_rmt_rx_channel(gpio_num_t gpio, rmt_channel_handle_t *out_ch
         return {false, DSHOT_RX_INIT_FAILED};
     }
 
-    // Start the receiver to wait for incoming telemetry data
-    rmt_symbol_word_t rx_symbols[GCR_BITS_PER_FRAME];
-    size_t rx_size_bytes = GCR_BITS_PER_FRAME * sizeof(rmt_symbol_word_t);
-
-    rmt_receive_config_t rmt_rx_config = {
-        .signal_range_min_ns = DSHOT_PULSE_MIN_NS,
-        .signal_range_max_ns = DSHOT_PULSE_MAX_NS,
-    };
-
-    if (rmt_receive(*out_channel, rx_symbols, rx_size_bytes, &rmt_rx_config) != DSHOT_OK)
-    {
-        return {false, DSHOT_RECEIVER_FAILED};
-    }
-
     return {true, DSHOT_RX_INIT_SUCCESS};
 }
 
@@ -94,6 +81,7 @@ dshot_result_t init_dshot_encoder(rmt_encoder_handle_t *out_encoder, const rmt_t
             .duration1 = rmt_ticks.t1l_ticks,
             .level1 = idle_level,
         },
+
         .flags = {
             .msb_first = 1 // DShot is MSB first
         }};
@@ -104,4 +92,4 @@ dshot_result_t init_dshot_encoder(rmt_encoder_handle_t *out_encoder, const rmt_t
     }
 
     return {true, DSHOT_ENCODER_INIT_SUCCESS};
-}
+}