wifi.ino

void WiFiTaskFunction(void * pvParameters) {
  while (true) {  // infinite loop
    // wifi recieve code:
    int packetSize = Udp.parsePacket();

    if (packetSize) {
      if (xSemaphoreTake(mutexReceive, 1) == pdTRUE) {
        receivedNewData = true;
        lastMessageTimeMillis = millis();

        Udp.read(packetBuffer, maxWifiRecvBufSize);
        for (int i = 0; i < maxWifiRecvBufSize; i++) {
          recvdData[i] = (byte)((int)(256 + packetBuffer[i]) % 256);
        }

        Udp.beginPacket();
        for (byte i = 0; i < numBytesToSend; i++) {  // send response, maybe change to go less frequently
          Udp.write(dataToSend[i]);
        }

        Udp.endPacket();

        xSemaphoreGive(mutexReceive);
      }
    }
  }
}

void WiFiEvent(WiFiEvent_t event) {
  switch (event) {
    case SYSTEM_EVENT_AP_START:
      Serial.println("configuring wifi");
      break;
    default: break;
  }

}

void setupWifi() {
  WiFi.softAP(robotSSID, robotPass, 4, 0, 1);  // start wifi network, on channel 4, not hiding, and only allowing one client
  delay(1000);
  WiFi.softAPConfig(IPAddress(10, 25, 21, 1), IPAddress(10, 25, 21, 1), IPAddress(255, 255, 255, 0));
  Udp.begin(2521);  // port 2521 on 10.25.21.1

  xTaskCreatePinnedToCore(  // create task to run WiFi recieving
    WiFiTaskFunction,   /* Function to implement the task */
    "WiFiTask",  /* Name of the task */
    15000,       /* Stack size in words */
    NULL,        /* Task input parameter */
    0,           /* Priority of the task */
    NULL,        /* Task handle. */
    0            /* Core on which task should run */
  );
}

boolean readBoolFromBuffer(byte &pos) {  // return boolean at pos position in recvdData
  byte msg = recvdData[pos];
  pos++;  // increment the counter for the next value
  return (msg == 1);
}

byte readByteFromBuffer(byte &pos) {  // return byte at pos position in recvdData
  byte msg = recvdData[pos];
  pos++;  // increment the counter for the next value
  return msg;
}

int readIntFromBuffer(byte &pos) {  // return int from four bytes starting at pos position in recvdData
  union {  // this lets us translate between two variable types (equal size, but one's four bytes in an array, and one's a four byte int)  Reference for unions: https:// www.mcgurrin.info/robots/127/
    byte b[4];
    int v;
  } d;  // d is the union, d.b acceses the byte array, d.v acceses the int

  for (int i = 0; i < 4; i++) {
    d.b[i] = recvdData[pos];
    pos++;
  }

  return d.v;  // return the int form of union d
}

float readFloatFromBuffer(byte &pos) {  // return float from 4 bytes starting at pos position in recvdData
  union {  // this lets us translate between two variable types (equal size, but one's 4 bytes in an array, and one's a 4 byte float) Reference for unions: https:// www.mcgurrin.info/robots/127/
    byte b[4];
    float v;
  } d;  // d is the union, d.b acceses the byte array, d.v acceses the float

  for (int i = 0; i < 4; i++) {
    d.b[i] = recvdData[pos];
    pos++;
  }

  return d.v;
}

void addBoolToBuffer(boolean msg, byte &pos) {  // add a boolean to the tosendData array
  dataToSend[pos] = msg;
  pos++;
}

void addByteToBuffer(byte msg, byte &pos) {  // add a byte to the tosendData array
  dataToSend[pos] = msg;
  pos++;
}

void addIntToBuffer(int msg, byte &pos) {  // add an int to the tosendData array (four bytes)
  union {
    byte b[4];
    int v;
  } d;  // d is the union, d.b acceses the byte array, d.v acceses the int

  d.v = msg;  // put the value into the union as an int

  for (int i = 0; i < 4; i++) {
    dataToSend[pos] = d.b[i];
    pos++;
  }
}

void addFloatToBuffer(float msg, byte &pos) {  // add a float to the tosendData array (four bytes)
  union {  // this lets us translate between two variables (equal size, but one's 4 bytes in an array, and one's a 4 byte float Reference for unions: https:// www.mcgurrin.info/robots/127/
    byte b[4];
    float v;
  } d;  // d is the union, d.b acceses the byte array, d.v acceses the float

  d.v = msg;

  for (int i = 0; i < 4; i++) {
    dataToSend[pos] = d.b[i];
    pos++;
  }
}