Autonomous drone that you already have in your pocket!

Step 1: Frame

Step 2: The circuits

Step 3: Software – analyzing

In this step, we want to analyze if we are able to:
1) read stick position from receiver
3) control servo
2) control ESC

For this propose we will use test setup mentioned on page 2. The components are:
1) Android IOIO with shield from page 2.
2) Receiver connected to digital pins 3-7
3) ESC connected to pin terminal 10
4) servo connected to pin terminal 11
My ESC includes BEC, that mean you can supply IOIO board form connected ESC. In this case, black lumper on our shield will be placed on left side, VIN pin on IOIO board will be connected to servo terminals (ESC will supply IOIO board).

For software development, you will need to install standard Android development environment and include IOIO libraries to your project. You can find tutorial here: https://www.sparkfun.com/tutorials/280 and doc umentation for Android IOIO project here: https://github.com/ytai/ioio/wiki

Our test application have simple gui, we will need:
2x slider to control servo and ESC (control PWM pins 10, 11)
5x label showing values from receiver (reed pulse width on pins 3-7)

Android IOIO offers Pulse Input. This type of input allows you to read width of incoming pulse, so its ideal for reading pulses form receiver. IOIO have 6 available ones (3 single-precision, 3 double-precision) you cant use 6 single or 6 double precision, you must split them. We will use PWM for driving ESCs and Servos. You can find functions for each individual pin here https://github.com/ytai/ioio/wiki/Getting-To-Know-The-Board

This test app have relay simple code:

public class MainActivity  extends IOIOActivity  {
private TextView ch1, ch2, ch3, ch4, ch5;
private SeekBar seekBar1, seekBar2;
private int seekBar1_val, seekBar2_val;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

ch1=(TextView)findViewById(R.id.ch1_text);
ch2=(TextView)findViewById(R.id.ch2_text);
ch3=(TextView)findViewById(R.id.ch3_text);
ch4=(TextView)findViewById(R.id.ch4_text);
ch5=(TextView)findViewById(R.id.ch5_text);

seekBar1 = (SeekBar) findViewById(R.id.seekBar1);
seekBar2 = (SeekBar) findViewById(R.id.seekBar2);

seekBar1_val = 1000;
seekBar2_val = 1500;

seekBar1.setMax(1000);
seekBar2.setMax(1000);

seekBar2.setProgress(500);

seekBar1.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
seekBar1_val = progress + 1000;
}
});

seekBar2.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
seekBar2_val = progress + 1000;
}
});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

class Looper extends BaseIOIOLooper {
private PulseInput pulse_ch1;
private PulseInput pulse_ch2;
private PulseInput pulse_ch3;
private PulseInput pulse_ch4;
private PulseInput pulse_ch5;

private PwmOutput M1;
private PwmOutput Servo;

public Float ch1_val;
public Float ch2_val;
public Float ch3_val;
public Float ch4_val;
public Float ch5_val;

private DigitalOutput led_;

@Override
protected void setup() throws ConnectionLostException {
pulse_ch1 = ioio_.openPulseInput(3, PulseMode.POSITIVE);
pulse_ch2 = ioio_.openPulseInput(4, PulseMode.POSITIVE);
pulse_ch3 = ioio_.openPulseInput(5, PulseMode.POSITIVE);
pulse_ch4 = ioio_.openPulseInput(new DigitalInput.Spec(6),
PulseInput.ClockRate.RATE_250KHz,
PulseInput.PulseMode.POSITIVE,
false);
pulse_ch5 = ioio_.openPulseInput(new DigitalInput.Spec(7),
PulseInput.ClockRate.RATE_250KHz,
PulseInput.PulseMode.POSITIVE,
false);

M1 = ioio_.openPwmOutput(10, 50);
Servo = ioio_.openPwmOutput(11, 50);

led_ = ioio_.openDigitalOutput(0, true);
}

@Override
public void loop() throws ConnectionLostException {
led_.write(false);
try {
ch1_val = pulse_ch1.getDuration() * 1000;
ch2_val = pulse_ch2.getDuration() * 1000;
ch3_val = pulse_ch3.getDuration() * 1000;
ch4_val = pulse_ch4.getDuration() * 1000;
ch5_val = pulse_ch5.getDuration() * 1000;

M1.setPulseWidth(seekBar1_val);
Servo.setPulseWidth(seekBar2_val);

Thread.sleep(100);
} catch (InterruptedException e) {
}
runOnUiThread(new Runnable() {
@Override
public void run() {
ch1.setText(String.format(“%.2f”, ch1_val));
ch2.setText(String.format(“%.2f”, ch2_val));
ch3.setText(String.format(“%.2f”, ch3_val));
ch4.setText(String.format(“%.2f”, ch4_val));
ch5.setText(String.format(“%.2f”, ch5_val));
}
});
}
}

@Override
protected IOIOLooper createIOIOLooper() {
return new Looper();
}

}

Our analysis went well, we can:
1) read stick position from receiver via digital inputs
3) control servo
2) control ESC

For more detail: Autonomous drone that you already have in your pocket!