Code for Nunchuk remote

Constants.h

//RGB setup
#define R 9 //all are pwm pins
#define G 6
#define B 5

//RF24 stuff
#define RF24_INT 3 //INT1
#define RF24_CE 7
#define RF24_CSN 10

//MPU6050 stuff
#define MPU_INT 2 //INT0
MPU6050 mpu; //default address 0x68
//chip is placed rotated forward 180deg

//Battery stuff
#define BATT A7 //V = 3.3 * val / 1023

//Control stuff
#define JOY_X A1 //map to 1 byte
#define JOY_Y A0
#define BUT_C A3 //needs pullups
#define BUT_Z A2

#define JOY_X_LOW 0
#define JOY_X_CENTER 520
#define JOY_X_HIGH 1023
#define JOY_Y_LOW 0
#define JOY_Y_CENTER 515
#define JOY_Y_HIGH 1023

#define JOY_MAPPED_LOW 0
#define JOY_MAPPED_CENTER 127
#define JOY_MAPPED_HIGH 255

Nunchuk_RX.ino

#include <SPI.h>
#include <RF24.h>
#include <math.h>

RF24 radio(7, 8);

const byte addr[6] = "12345";

struct Dat { //limited to 32 bytes
  uint8_t batteryVoltage; //v = batteryVoltage / 100
  uint8_t joyXPos;
  uint8_t joyYPos;
  uint8_t butC;
  uint8_t butZ;
  int16_t ax, ay, az;
  int16_t gx, gy, gz;
} dat; //creates instance dat

void setup() {
  Serial.begin(115200);
  while(!Serial);
  radio.begin();
  radio.setChannel(125);
  radio.setPALevel(RF24_PA_MAX);
  radio.setDataRate(RF24_250KBPS);
  radio.enableDynamicPayloads();
  radio.openReadingPipe(0, addr);
  radio.startListening();

  attachInterrupt(1, doRadio, FALLING);
}

void loop() {
}

void teensySwapVars() { //teensy swaps byte order compared to avr
  dat.ax = dat.ax << 8 | (dat.ax >> 8 & 0x00FF);
  dat.ay = dat.ay << 8 | (dat.ay >> 8 & 0x00FF);
  dat.az = dat.az << 8 | (dat.az >> 8 & 0x00FF);
  dat.gx = dat.gx << 8 | (dat.gx >> 8 & 0x00FF);
  dat.gy = dat.gy << 8 | (dat.gy >> 8 & 0x00FF);
  dat.gz = dat.gz << 8 | (dat.gz >> 8 & 0x00FF);
}

void doRadio() {
  bool tx, fail, rx;
  radio.whatHappened(tx, fail, rx);
  if (radio.available(0)) {
    radio.read(&dat, sizeof(dat));
    teensySwapVars();
    double g = sqrt(1.0*dat.ax*dat.ax + 1.0*dat.ay*dat.ay + 1.0*dat.az*dat.az) / 4096;
    Serial.print(g);
    Serial.print(" ");
    Serial.print(dat.batteryVoltage / 100.0);
    Serial.print(" ");
    Serial.print(dat.joyXPos);
    Serial.print(" ");
    Serial.print(dat.joyYPos);
    Serial.print(" ");
    Serial.print(dat.butC);
    Serial.print(" ");
    Serial.print(dat.butZ);
    Serial.print(" ");
    Serial.print(dat.ax);
    Serial.print(" ");
    Serial.print(dat.ay);
    Serial.print(" ");
    Serial.print(dat.az);
    Serial.print(" ");
    Serial.print(dat.gx);
    Serial.print(" ");
    Serial.print(dat.gy);
    Serial.print(" ");
    Serial.print(dat.gz);
    Serial.println();
  }
}

Nunchuk_TX.ino

#include <SPI.h>
#include <RF24.h>
#include "I2Cdev.h"
#include <Wire.h>
#include "MPU6050.h"

#include "Constants.h"

const byte addr[6] = "12345";

RF24 radio(RF24_CE, RF24_CSN);

struct Dat { //limited to 32 bytes
  uint8_t batteryVoltage; //v = batteryVoltage / 100
  uint8_t joyXPos;
  uint8_t joyYPos;
  uint8_t butC;
  uint8_t butZ;
  int16_t ax, ay, az;
  int16_t gx, gy, gz;
} dat; //creates instance dat

void setup() {
  OSCCAL = 0xAD; //specific for each device
  Serial.begin(115200); //possible with calibrated internal RC

  RGB_setup();
  RF24_setup(); //could potentially use ack packets
  MPU6050_setup();
  Control_setup();
}

void loop() {
  dat.batteryVoltage = 330 * (long) analogRead(BATT) / 1023; //casting as long bc overflow error
  //interesting c++ does math as ints first then converts to long
  dat.joyXPos = getJoy_X();
  dat.joyYPos = getJoy_Y();
  dat.butC = !digitalRead(BUT_C);
  dat.butZ = !digitalRead(BUT_Z);
  mpu.getMotion6(&dat.ax, &dat.ay, &dat.az, &dat.gx, &dat.gy, &dat.gz);
  
  radio.startWrite(&dat, sizeof(dat), 0);
}

//interrupt methods
void doRadio() {
  bool tx, fail, rx;
  radio.whatHappened(tx, fail, rx);
  digitalWrite(R, !tx);
  digitalWrite(G, tx);
}

//general methods
uint8_t getJoy_X() {
  int val = constrain(analogRead(JOY_X), JOY_X_LOW, JOY_X_HIGH);
  if (val <= JOY_X_CENTER) {
    return map(val, JOY_X_LOW, JOY_X_CENTER, JOY_MAPPED_LOW, JOY_MAPPED_CENTER);
  } else {
    return map(val, JOY_X_CENTER, JOY_X_HIGH, JOY_MAPPED_CENTER, JOY_MAPPED_HIGH);
  }
}

uint8_t getJoy_Y() {
  int val = constrain(analogRead(JOY_Y), JOY_Y_LOW, JOY_Y_HIGH);
  if (val <= JOY_Y_CENTER) {
    return map(val, JOY_Y_LOW, JOY_Y_CENTER, JOY_MAPPED_LOW, JOY_MAPPED_CENTER);
  } else {
    return map(val, JOY_Y_CENTER, JOY_Y_HIGH, JOY_MAPPED_CENTER, JOY_MAPPED_HIGH);
  }
}

Setup.ino

void RGB_setup() {
  pinMode(R, OUTPUT);
  pinMode(G, OUTPUT);
  pinMode(B, OUTPUT);
  for (int i = 0; i < 4; i++) {
    digitalWrite(B, HIGH);
    delay(70);
    digitalWrite(B, LOW);
    delay(70);
  }
}

void RF24_setup() {
  radio.begin();
  radio.setChannel(125); //outside range of wifi
//  radio.setPayloadSize(6); //not necessary with dynamic payloads
  radio.setPALevel(RF24_PA_MAX); //max power
  radio.setDataRate(RF24_250KBPS); //lowest speed, longest range
  radio.enableDynamicPayloads();
  radio.openWritingPipe(addr);
  attachInterrupt(digitalPinToInterrupt(RF24_INT), doRadio, FALLING);
}

void MPU6050_setup() {
  Wire.begin();
  Wire.setClock(400000); //400kHz
  mpu.initialize();
  mpu.setFullScaleAccelRange(MPU6050_ACCEL_FS_16);
  mpu.setFullScaleGyroRange(MPU6050_GYRO_FS_2000);
  mpu.setXGyroOffset(34);
  mpu.setYGyroOffset(26);
  mpu.setZGyroOffset(25);
  mpu.setXAccelOffset(-1416);
  mpu.setYAccelOffset(-2640);
  mpu.setZAccelOffset(1135);
  mpu.setXFineGain(15);
  mpu.setYFineGain(36);
  mpu.setZFineGain(-33);
}

void Control_setup() {
  pinMode(BUT_C, INPUT_PULLUP);
  pinMode(BUT_Z, INPUT_PULLUP);
}