...cleaning

...experimental DSHOT1200 support. Who really needs DSHOT1200???

DShotRMT.cpp

@@ -19,8 +19,8 @@ void DShotRMT::begin()
     {
         rmt_rx_channel_config_t rmt_rx_channel_config = {
             .gpio_num = _gpio,
-            .clk_src = RMT_CLK_SRC_DEFAULT,
+            .clk_src = DSHOT_CLOCK_SRC_DEFAULT,
-            .resolution_hz = DEFAULT_RES_HZ,
+            .resolution_hz = DSHOT_RMT_RESOLUTION,
             .mem_block_symbols = 64,
             .flags = {
                 .invert_in = false,
@@ -32,8 +32,8 @@ void DShotRMT::begin()
 
     rmt_tx_channel_config_t rmt_tx_channel_config = {
         .gpio_num = _gpio,
-        .clk_src = RMT_CLK_SRC_DEFAULT,
+        .clk_src = DSHOT_CLOCK_SRC_DEFAULT,
-        .resolution_hz = DEFAULT_RES_HZ,
+        .resolution_hz = DSHOT_RMT_RESOLUTION,
         .mem_block_symbols = 64,
         .trans_queue_depth = 1,
         .flags = {
@@ -88,11 +88,10 @@ void DShotRMT::setThrottle(uint16_t throttle)
     dshot_packet = (dshot_packet << 4) | crc;
 
     // Encode DShot Paket
-    rmt_symbol_word_t symbols[32] = {};
+    rmt_symbol_word_t symbols[DSHOT_BITS_PER_FRAME] = {}; // 16 DShot Bits + Pause Bit
     size_t count = 0;
 
     buildFrameSymbols(dshot_packet, symbols, count);
-
     // Reset RMT Signnal loop before sending new value
     rmt_disable(_rmt_tx_channel);
     rmt_enable(_rmt_tx_channel);
@@ -104,12 +103,21 @@ void DShotRMT::setThrottle(uint16_t throttle)
 //
 void DShotRMT::buildFrameSymbols(uint16_t dshot_packet, rmt_symbol_word_t *symbols, size_t &count)
 {
+    // Always start from the top
+    count = 0;
+
+    //
     uint32_t ticks_per_bit = 0;
     uint32_t ticks_zero_high = 0;
     uint32_t ticks_one_high = 0;
 
     switch (_mode)
     {
+    case DSHOT_OFF:
+        ticks_per_bit = 0;
+        ticks_zero_high = 0;
+        ticks_one_high = 0;
+        break;
     case DSHOT150:
         ticks_per_bit = 64;
         ticks_zero_high = 24;
@@ -125,11 +133,18 @@ void DShotRMT::buildFrameSymbols(uint16_t dshot_packet, rmt_symbol_word_t *symbo
         ticks_zero_high = 6;
         ticks_one_high = 12;
         break;
+    case DSHOT1200:
+        ticks_per_bit = 8;
+        ticks_zero_high = 3;
+        ticks_one_high = 6;
+        break;
     }
 
+    //
     uint32_t ticks_zero_low = ticks_per_bit - ticks_zero_high;
     uint32_t ticks_one_low = ticks_per_bit - ticks_one_high;
 
+    // Fill the 16 DShot-Bits Array with selected timings
     for (int i = 15; i >= 0; i--)
     {
         bool bit = (dshot_packet >> i) & 0x01;
@@ -140,6 +155,7 @@ void DShotRMT::buildFrameSymbols(uint16_t dshot_packet, rmt_symbol_word_t *symbo
         count++;
     }
 
+    // Append the Pause Bits
     symbols[count].level0 = 0;
     symbols[count].duration0 = ticks_per_bit * PAUSE_BITS;
     symbols[count].level1 = 0;

DShotRMT.h

@@ -12,20 +12,29 @@
 #include <driver/rmt_tx.h>
 #include <driver/rmt_rx.h>
 
+// DShot Protocol Constants
 static constexpr auto DSHOT_THROTTLE_FAILSAVE = 0;
 static constexpr auto DSHOT_THROTTLE_MIN = 48;
 static constexpr auto DSHOT_THROTTLE_MAX = 2047;
-static constexpr auto DEFAULT_RES_HZ = 10 * 1000 * 1000; // 10 MHz
+static constexpr auto DSHOT_BITS_PER_FRAME = 17;
 static constexpr auto PAUSE_BITS = 21;
 static constexpr auto DSHOT_NULL_PACKET = 0b0000000000000000;
+static constexpr auto DSHOT_FULL_PACKET = 0b1111111111111111;
+static constexpr auto NO_ERPM_SIGNAL = 0;
+static constexpr auto DSHOT_CLOCK_SRC_DEFAULT = RMT_CLK_SRC_DEFAULT;
+static constexpr auto DSHOT_RMT_RESOLUTION = 10 * 1000 * 1000; // set 10 MHz RMT Resolution
 
+// DShot Mode Selection
 typedef enum dshot_mode_e
 {
+    DSHOT_OFF,
     DSHOT150,
     DSHOT300,
-    DSHOT600
+    DSHOT600,
+    DSHOT1200
 } dshot_mode_t;
 
+//
 class DShotRMT
 {
 public:
@@ -41,7 +50,7 @@ private:
     gpio_num_t _gpio;
     dshot_mode_t _mode;
     bool _isBidirectional;
-    uint16_t _lastThrottle = 0;
+    uint16_t _lastThrottle = DSHOT_FULL_PACKET;
     uint16_t dshot_packet = DSHOT_NULL_PACKET;
 
     rmt_channel_handle_t _rmt_tx_channel = nullptr;

examples/dshot300/dshot300.ino

@@ -17,7 +17,7 @@ constexpr auto USB_SERIAL_BAUD = 115200;
 constexpr auto MOTOR01_PIN = GPIO_NUM_17;
 constexpr auto DSHOT_MODE = DSHOT300;
 
-// BiDirectional DShot Support
+// BiDirectional DShot Support (default: false)
 constexpr auto IS_BIDIRECTIONAL = true;
 
 // Setup Motor Pin, DShot Mode and optional BiDirectional Support
@@ -25,6 +25,7 @@ DShotRMT motor01(MOTOR01_PIN, DSHOT_MODE, IS_BIDIRECTIONAL);
 
 void setup()
 {
+  // Start the USB Serial Port
   USB_Serial.begin(USB_SERIAL_BAUD);
 
   // Initialize DShot Signal
@@ -34,16 +35,23 @@ void setup()
   motor01.setThrottle(DSHOT_THROTTLE_MIN);
 
   //
+  USB_Serial.println("**********************");
   USB_Serial.println("DShotRMT Demo started.");
-  USB_Serial.println("Enter a throttle value (48–2047):");
+  USB_Serial.println("Enter a throttle value (48 – 2047):");
 }
 
 void loop()
 {
-  // Simple as can be
+  // Read value input from Serial
   int throttle_input = readSerialThrottle();
 
+  // Now send the value
   motor01.setThrottle(throttle_input);
+
+  // BiDirectional DShot: print out the received eRPMs
+  if (IS_BIDIRECTIONAL)
+  {
+  }
 }
 
 // Reads throttle value from serial input
@@ -63,8 +71,8 @@ int readSerialThrottle()
 
     USB_Serial.print("Throttle set to: ");
     USB_Serial.println(last_throttle);
-
+    USB_Serial.println("***********************************");
-    USB_Serial.println("Enter a throttle value (48–2047):");
+    USB_Serial.println("Enter a throttle value (48 – 2047):");
   }
 
   return last_throttle;