adds code from: https://github.com/JeroenDelcour/spincoater without mods

src/dshot.py

@@ -0,0 +1,113 @@
+import time
+
+from esp32 import RMT
+
+
+class Dshot:
+    def __init__(self, pin):
+        # https://brushlesswhoop.com/dshot-and-bidirectional-dshot/
+        # clock freq = 80  # Mhz
+        # clock divider = 7
+        # pulse time = 1 / (80 / 7) = 0.0875 us
+        # bit duration = 3.33 us
+        # T1H = 2.50 us
+        # T0H = 1.25 us
+        self._ON_PULSES = 57  # number of pulses for an ON bit
+        self._OFF_PULSES = 29  # number of pulses for an OFF bit
+        self._BIT_PULSES = 76  # total number of pulses per bit
+        self._PAUSE_PULSES = 21  # pause after sending packet
+
+        self.rmt = RMT(0, pin=pin, clock_div=7)
+
+        self._arm()
+        self._enable_telemetry()
+
+    def _arm(self, duration=2):
+        """
+        Send arming sequence.
+
+        Args:
+            duration: How long to send the arming sequence, in seconds.
+        """
+        t0 = time.time()
+        while time.time() - t0 < duration:
+            self.set_throttle(0)
+            # time.sleep(0.01)
+
+    def _enable_telemetry(self):
+        for i in range(6):
+            value = self._create_packet(33)
+            self._send(value)
+        for i in range(6):
+            value = self._create_packet(34)
+            self._send(value)
+        for i in range(6):
+            value = self._create_packet(35)
+            self._send(value)
+        for i in range(6):
+            value = self._create_packet(12)
+            self._send(value)
+        time.sleep(0.040)
+
+        # for i in range(10):
+        #     self._send(self._create_packet(6))
+        #     time.sleep(0.012)
+
+        # self._send(self._create_packet(42))
+        # self._send(self._create_packet(43))
+        # self._send(self._create_packet(44))
+        # self._send(self._create_packet(45))
+        # self._send(self._create_packet(46))
+        # self._send(self._create_packet(47))
+
+        # beep
+        # time.sleep(0.050)
+        # for i in range(5):
+        #     self._send(self._create_packet(i + 1))
+        #     time.sleep(0.250)
+
+    def _encode_throttle(self, value):
+        # 11 bit throttle: 2048 possible values.
+        # 0 is reserved for disarmed. 1-47 are reserved for special commands.
+        # Leaving 48 to 2047 (2000 steps) for the actual throttle value
+        value = min(max(value, 0.0), 1.0)  # clamp to between 0 and 1
+        if value == 0:
+            value = 0  # disarmed
+        else:
+            value = int(value * 1999 + 48)
+        return value
+
+    def set_throttle(self, value: float, telemetry=True):
+        """
+        Set throttle to a value between 0 and 1.
+        """
+        value = self._encode_throttle(value)
+        value = self._create_packet(value)
+        self._send(value)
+
+    def _create_packet(self, value, telemetry=True):
+        # add telemetry bit
+        value = (value << 1) | telemetry
+
+        # add CRC (Cyclic Redundancy Check)
+        crc = (value ^ (value >> 4) ^ (value >> 8)) & 0x0F
+        value = (value << 4) | crc
+
+        return value
+
+    def _send(self, value):
+        """
+        Send value to ESC.
+        """
+        duration = []
+
+        for i in reversed(range(16)):
+            bit = (value & (2**i)) == 2**i  # select bit
+            if bit == 1:
+                duration += [self._ON_PULSES, self._BIT_PULSES - self._ON_PULSES]
+            else:
+                duration += [self._OFF_PULSES, self._BIT_PULSES - self._OFF_PULSES]
+
+        duration[-1] += self._PAUSE_PULSES
+
+        self.rmt.write_pulses(duration, True)