Android Marionette

Welcome to the Android Marionette Project Page!

Table of Contents

[Introduction] (#introduction)
Materials
Overall Schematic
Servo Motor Setup and Housing
Android
Arduino
Concluding Thoughts Links to Arduino and Android Code

## Introduction

This project was a partner collaboration between Thibaud Cochet and Jacqueline Ong and was created for Harvey Mudd College's [E190P: Embedded Systems] (http://www3.hmc.edu/~jspjut/class/e190p/) course taught by [Professor Josef Spjut] (http://jspjut.github.io/).

The goal of this project was to build, assemble, and program a marionette to be remote-controlled via an Android App. A marionette is essentially a puppet that is controlled by a horizontal control bar connected to the puppet via strings. To mobilize the marionette, servo motors, attached to an Arduino Uno, will receive angle-motion commands from an Android app via bluetooth. The Android app user can then either move the marionette's limbs individually or the human user could toggle a screen and choose four preset moves by controlling the limb's correspondng servo motors.

To see a video demo of some of the sample moves of our final project, click the link below.

## Materials

If there is no cost listed, then it was free or was provided, courtesy of the HMC Microprocessors lab and wood shop.

Quantity	Item	Supplier	Cost
9	Hitec HS-422 Servo Motors	Adafruit	$90
1	Arduino Uno	Amazon	$35
1	Monkey Marionette	Amazon	$13
3	12" x 36" Plywood Panels	Amazon
9	Skinny Popsicle Sticks	Amazon
	Total Cost		$138

Other items not listed, but we used were the

• Switch
• 1 kOhm resistor
• Wire
• Screws
• Electric tape
• Super glue
• Pull-ties

Because of the steep cost in motors, we were able to secure partial funding from HMC's Fabrication Studio to offset the hardware cost. However, we would recommend ordering cheaper servos that can achieve the objective, such as the TowerPro servo motors that cost $5 each as opposed to $10 for each Hitec servo motor.

## Overall Schematic

Below is the overall schematic of the electronics of the servo motors.

For the BlueSMiRF, the pins (from left to right) are CTS, VCC, GND, TX, RX, RTS.

You have the option to have it battery-powered or PC-powered via USB. Because we were coding, we decided to power by PC.

Note: For this one-way Bluetooth connection (from Android to Arduino) to work, connect the BlueSMiRF's TX pin to the Arduino Uno's RX pin.

## Servo Motor Setup and Housing When deciding the servo motor setup, we chose one, such that we could maximize the amount of motion the marionette could achieve. We chose to have nine servo motors. Five control the vertical motion for hands (2), feet (2), and head (1) Four control the horizontal motion for hands (2) and feet (2)  The wooden housing was made from three donated sheets of wood drilled together in the wood shop to create the mount and support for the servo motor setup. ## Android

User Interface

For the user interface, we designed the app to have three screens as shown below.

A main screen to choose between two sub-screens whether you wanted to...

1. control the marionette's individual limbs
2. choose from a selection of four preset moves the marionette could perform.

Sub-Screen 1: Dance Move Screen

There are four buttons corresponding to four preset moves that allow the user to see a few fun moves the marionette can do.

Sub-Screen 2: Manual Move Screen

There are eight "seekbars" that lets the user scroll the seekbar to a desired angle (i.e.: extent) and ultimately customize the marionette's moves. Once the user lets go of the scroll bar the marionette will hold that position until the user chooses to reset the marionette's position to an upright position. Although the "right" and "left" labels are referencing the actual marionette's limbs, the seekbars are located on the screen in the general location where the human user views that corresponding limb.

Creating the Android App

We used Android Developer Tools Eclipse Platform to code the Android App with the desirable interface and necessary buttons to command the servo motors.

Below is the code used to control the left leg's horizontal motion via the Android app scroll bar control for the left leg horizontal motion.

// Left Leg Horizontal Motion
	LegLeftX.setOnSeekBarChangeListener(new OnSeekBarChangeListener()
	{
		int ProgressLegLeftX = 0;
		public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)
		{
			ProgressLegLeftX = progress;
		}
		public void onStartTrackingTouch(SeekBar seekBar)
		{
			//begin tracking clicking on seekBar
		}
		public void onStopTrackingTouch(SeekBar seekBar)
		{
			if(ProgressLegLeftX <= 9) sendData("LLX00"+ Integer.toString(ProgressLegLeftX)); 
			else if(ProgressLegLeftX <= 99) sendData("LLX0"+ Integer.toString(ProgressLegLeftX));
			else if(ProgressLegLeftX == 100)sendData("LLX"+ Integer.toString(ProgressLegLeftX));
			Toast.makeText(manualmove.this, "Leg Left X "+ ProgressLegLeftX +"%", Toast.LENGTH_SHORT).show();
		}

Bluetooth Connection - Sending Data

To send data, we used the sendData() command and sent a char string, six characters long. The first three chars tell which servo motor (i.e.: which limb) to move. The last three chars tell that motor the angle the servo motor's arm will rotate.

For example: "ALX100" The "ALX" stands for ArmLeftX, so the servo motor controlling the left arm's horizontal motion will move by 100 degrees.

Note: Your manifest file should have the following code to grant the necessary "permissions" for Bluetooth to work.

    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    <uses-permission android:name="android.permission.BLUETOOTH"/>

For full Android Code, click here.

## Arduino

Creating the Servo Motor Code

We used the standard Arduino IDE to code the servo motors to mobilize the marionette.

Calibrating Servo Motors

Below is a diagram showing how the servo motors were oriented against the housing as well as the angle orientation of the servo motors with respect to the housing.

Bluetooth Setup - Receiving Data

To setup the Bluetooth, the following bit of starter code is helpful to setup Serial to start receiving data.

void setup() 
{...
     Serial.begin(115200);
}

void loop()
{
  if(Serial.available() >= 6) // for six characters we are sending from Android
  {
    for (byte i=0; i<=6; i++)
    {
      command[i] = Serial.read();
    }
  }
}

Check your baud rate matches that of your bluetooth modem to ensure that the Arduino was processing appropriately to register the data received from the bluetooth connection. Then, to setup the transfer the data, we set Serial as available and wait until all six have been transferred before we begin reading the values into our char array called command.

For full Arduino Code, see the next section.

Concluding Thoughts

We did achieve our goal to create a "remote-controlled" marionette using a bluetooth android app. Despite the simple setup, we were still able to mobilize our marionette to yield the expected motions.

If given more time, we would

• program additional more sophisticated moves
• determine method to minimize excessive movements caused by the marionette horizontal motions
• create an enclosure for all the servo motors and wiring on the top of the housing for aesthetics

Arduino and Android Code

Arduino Code

Android App Code

Main Screen

ThibJackMario.java
activity_thib_jack_mario.xml

Manual Move Screen

Manual Move Java File
Manual Move Activity File

Preset Move Screen

Preset Move Java File
Preset Move Activity File

Manifest File

Manifest (Permissions) File