20 controller receive radio control signals

src/constants.h

@@ -0,0 +1,14 @@
+#pragma once
+
+struct RadioPacketChars {
+  char Armed;
+  char Pitch;
+  char Roll;
+  char Throttle;
+  char Yaw;
+
+  constexpr RadioPacketChars()
+      : Armed('A'), Pitch('P'), Roll('R'), Throttle('T'), Yaw('Y') {}
+};
+
+constexpr RadioPacketChars DefaultRadioPacketChars{};

src/flight-controller/flightController.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "battery.h"
+#include "receiver.h"
 #include "servoController.h"
 #include "ultrasonicSensor.h"
 #include "view.h"
@@ -15,7 +16,7 @@
 
 #define MICROBIT_UBIT_AS_STATIC_OBJECT
 
-enum class State : uint16_t { CALIBRATING, CHARGING, DISARMED, ARMED, PANIC };
+enum class State : uint8_t { CALIBRATING, CHARGING, DISARMED, ARMED, PANIC };
 
 struct FlightState {
   int altitude;

src/flight-controller/receiver.cpp

@@ -0,0 +1,46 @@
+#include "receiver.h"
+#include "../constants.h"
+#include "flightController.h"
+
+#include <MicroBit.h>
+
+static RadioPacketChars radioPacketChars = DefaultRadioPacketChars;
+const uint8_t PACKET_CHAR_INDEX = 14;
+const uint8_t PACKET_VALUE_INDEX = 9;
+
+static uint8_t packet[32];
+
+// Reference variables
+static int pitch = 0;
+static int roll = 0;
+static int throttle = 0;
+static int yaw = 0;
+static bool armed = false;
+
+static void readRadioPacket() {
+  uBit.radio.datagram.recv(packet, sizeof(packet));
+  char packetChar = packet[PACKET_CHAR_INDEX];
+
+  if (packetChar == radioPacketChars.Pitch) {
+    memcpy(&pitch, &packet[PACKET_VALUE_INDEX], 4);
+  } else if (packetChar == radioPacketChars.Armed) {
+    int32_t value = 0;
+    memcpy(&value, &packet[PACKET_VALUE_INDEX], 4);
+    armed = value != 0;
+  } else if (packetChar == radioPacketChars.Roll) {
+    memcpy(&roll, &packet[PACKET_VALUE_INDEX], 4);
+  } else if (packetChar == radioPacketChars.Throttle) {
+    memcpy(&throttle, &packet[PACKET_VALUE_INDEX], 4);
+  } else if (packetChar == radioPacketChars.Yaw) {
+    memcpy(&yaw, &packet[PACKET_VALUE_INDEX], 4);
+  }
+}
+
+void FlushRadioBuffer() {
+  // sizeof returns the byte size of struct
+  for (unsigned int i = 0; i < sizeof(radioPacketChars); i++) {
+    readRadioPacket();
+  }
+}
+
+bool IsDroneArmed() { return armed; }

src/flight-controller/receiver.h

@@ -0,0 +1,4 @@
+#pragma once
+
+bool IsDroneArmed();
+void FlushRadioBuffer();

src/flight-controller/view.cpp

@@ -1,5 +1,7 @@
 #include "view.h"
+#include "../utilities.h"
 #include "flightController.h"
+#include "receiver.h"
 #include <MicroBit.h>
 #include <cmath>
 
@@ -44,5 +46,6 @@ void UpdateView() {
 
   Image ledDisplay = Image(LED_DISPLAY_SIZE, LED_DISPLAY_SIZE);
   viewBatteryLevel(ledDisplay);
+  DisplayArmed(IsDroneArmed(), ledDisplay);
   uBit.display.print(ledDisplay);
 }

src/hand-controller/README.md

@@ -102,3 +102,20 @@ $$
 
 ![img/display.jpg](../../img/display.jpg)
 
+#### Radio communication
+
+We use a radio channel to send packets between the hand controller and flight controller. These packets contains control variables and setpoints.
+
+Packet Spec per byte:
+| 0              | 1 ... 4       | 5 ... 8           | 9 ... 28
+----------------------------------------------------------------
+| packet type    | system time   | serial number     | payload
+
+- Packet type = 1 is the first byte
+- The following four bytes (int size) is the system time
+- The following four bytes (int size) is the serial number, which is set to 0
+
+The Payload is divided in two: 
+- The first four payload bytes (9, 10, 11, 12) is the integer value sent
+- The following payload byte (13) is the name length
+- The following payload byte (14) is the identifying char ('P', 'A', 'R', 'T' 'Y')

src/hand-controller/transmitter.cpp

@@ -1,10 +1,13 @@
 #include "transmitter.h"
+#include "../constants.h"
 #include "buttons.h"
 #include "handController.h"
 #include "orientation.h"
 #include "pins.h"
 #include <MicroBit.h>
 
+static RadioPacketChars radioPacketChars = DefaultRadioPacketChars;
+
 /*
 // Packet Spec:
 // | 0              | 1 ... 4       | 5 ... 8           | 9 ... 28
@@ -30,7 +33,7 @@ static void sendValue(char name, int value) {
   uint8_t buf[32];
   int i = 0;
 
-  // Packet type value
+  // Packet type value (first byte)
   buf[i++] = 0x01;
 
   // Timestamp (4 bytes)
@@ -48,18 +51,19 @@ static void sendValue(char name, int value) {
   i += 4;
 
   // Name length
-  buf[i++] = 1;
-  memcpy(&buf[i], &name, 1);
+  buf[i++] = 1; // 13th byte
+  // Name
+  memcpy(&buf[i], &name, 1); // 14th byte
   i += 1;
 
   // Send the packet
   uBit.radio.datagram.send(buf, i);
 }
 
 void TransmittData() {
-  sendValue('P', GetPitch());
-  sendValue('A', IsArmed());
-  sendValue('R', GetRoll());
-  sendValue('T', GetThrottle());
-  sendValue('Y', GetYaw());
+  sendValue(radioPacketChars.Pitch, GetPitch());
+  sendValue(radioPacketChars.Armed, IsArmed());
+  sendValue(radioPacketChars.Roll, GetRoll());
+  sendValue(radioPacketChars.Throttle, GetThrottle());
+  sendValue(radioPacketChars.Yaw, GetYaw());
 }

src/hand-controller/view.cpp

@@ -1,4 +1,5 @@
 #include "view.h"
+#include "../utilities.h"
 #include "buttons.h"
 #include "handController.h"
 #include "orientation.h"
@@ -8,27 +9,6 @@
 // MicroBit display
 const uint16_t LED_DISPLAY_SIZE = 5;
 const int LED_ON = 255;
-int pulseDirection = 15;
-int armedPulse = 0;
-
-static void updatePulse() {
-  armedPulse += pulseDirection;
-
-  if (armedPulse == 255) {
-    pulseDirection = -15;
-  } else if (armedPulse == 0) {
-    pulseDirection = 15;
-  }
-}
-
-static void displayArmed(Image &ledDisplay) {
-  if (IsArmed()) {
-    updatePulse();
-    ledDisplay.setPixelValue(0, 0, armedPulse);
-  } else {
-    armedPulse = 0;
-  }
-}
 
 static void displayThrottle(Image &ledDisplay) {
   int throttle = GetThrottle();
@@ -59,7 +39,7 @@ void UpdateDisplay() {
   uBit.display.clear();
 
   Image ledDisplay = Image(LED_DISPLAY_SIZE, LED_DISPLAY_SIZE);
-  displayArmed(ledDisplay);
+  DisplayArmed(IsArmed(), ledDisplay);
   displayThrottle(ledDisplay);
   displayPitchRoll(ledDisplay);
   displayYaw(ledDisplay);

src/main.cpp

@@ -25,8 +25,9 @@ static void FlightController() {
 
   while (true) {
     SetBatteryInfo();
+    FlushRadioBuffer();
     UpdateView();
-    uBit.sleep(1000);
+    uBit.sleep(100);
   }
 }
 
@@ -47,6 +48,6 @@ static void HandController() {
 int main() {
   uBit.init();
   initRadio();
-  HandController();
+  FlightController();
   return 0;
 }

src/utilites.cpp

@@ -0,0 +1,23 @@
+#include "utilities.h"
+
+static int pulseDirection = 15;
+static int armedPulse = 0;
+
+static void updatePulse() {
+  armedPulse += pulseDirection;
+
+  if (armedPulse == 255) {
+    pulseDirection = -15;
+  } else if (armedPulse == 0) {
+    pulseDirection = 15;
+  }
+}
+
+void DisplayArmed(bool isArmed, Image &ledDisplay) {
+  if (isArmed) {
+    updatePulse();
+    ledDisplay.setPixelValue(0, 0, armedPulse);
+  } else {
+    armedPulse = 0;
+  }
+}

src/utilities.h

@@ -0,0 +1,4 @@
+#pragma once
+#include <MicroBit.h>
+
+void DisplayArmed(bool isArmed, Image &ledDisplay);