makeblock starter kit | Secret Science Lab

The 3-wheel car is built with the Makeblock Robot Starter Kit. (Plus some Legos for style.) It has a Bluetooth module. It is controlled by the phone’s gyros via Bluetooth. You drive it like a steering wheel with two hands, or like Darth Vader with one hand.

1. Code for the smartphone below. I saved this as gyroCar.py and transferred it to my phone (LG Optimus Dynamic). Then I execute/run it using SL4A from the phone itself:

#!/usr/bin/env python

import android
import sys
import time

class RoboComm:
  def __init__(self, droid, baotooth):
    self.droid = droid
    self.baotooth = baotooth
    self.lastCommand = None

  def sendCmd(self, cmd):
    if cmd is None:
      return 

    if "fwd" in cmd or "bwd" in cmd \
      or "left" in cmd or "right" in cmd \
      or "stop" in cmd:
      # don't send redundant movement commands to save data
      if self.lastCommand == cmd:
        return

    print cmd
    self.lastCommand = cmd

    if self.baotooth:
      self.droid.bluetoothWrite(cmd + "\n", self.baotooth)

class DroidGyroJoystick:
  def __init__(self, droid):
    self.droid = droid
    self.orient = None
    self.joyFwdBwdPos = 0
    self.joyLeftRightPos = 0
    self.accelZero = 0.4 # deflection of less than this is treated as no deflection
    self.turnZero = 0.3 # deflection of less than this is treated as no deflection
    self.minSpeed = 0.4

    if self.droid:
      self.droid.startSensingTimed(1, 200)

    self.updateOrient()

  def updateOrient(self):
    if self.droid:
      self.orient = self.droid.sensorsReadOrientation().result

  def getJoyCommand(self):
    #
    # translate gyro reading to joystick input
    #
    if not self.orient:
      return None

    if self.orient[0] is None:
      return None

    turn = self.orient[1] # [1.57=left, 0=stop, -1.57=right]
    accel = self.orient[2] # [0=fwd, -1.57=stop, -3.14=bwd] 

    #if accel > 0 and accel < 0.7:
    #  # tipping phone too far forward but let's treat as fwd anyway
    #  accel = 0

    if turn > 1.57:
      turn = 1.57 # hard left, past horizon = max left
    if turn < -1.57:
      turn = -1.57 # hard right, past horizon = max right

    if accel > 0:
      # phone is inverted - send stop signal
      return "!stop"

    # normalize turn and accel values to [-1.0, 1.0]
    turn = (-turn) / 1.57
    accel = ((-accel) - 1.57) / 1.57

    # filter for neutral pos
    if turn > -self.turnZero and turn < self.turnZero:
      turn = 0
    if accel > -self.accelZero and accel < self.accelZero:
      accel = 0

    # set min speed
    if turn > 0:
      turn = max(self.minSpeed, turn)
    if turn < 0:
      turn = min(-self.minSpeed, turn)
    if accel > 0:
      accel = max(self.minSpeed, accel)
    if accel < 0:
      accel = min(-self.minSpeed, accel)

    self.joyFwdBwdPos = int(accel * 10)
    self.joyLeftRightPos = int(turn * 10)

    # decide move cmd based on vectors
    fbmag = min(abs(self.joyFwdBwdPos) + 1, 10)
    lrmag = min(abs(self.joyLeftRightPos) + 2, 10)

    if self.joyFwdBwdPos < 0:
      if self.joyLeftRightPos < 0:
        return "!fwdleft %d %d" % (fbmag, lrmag)
      elif self.joyLeftRightPos > 0:
        return "!fwdright %d %d" % (fbmag, lrmag)
      else:
        return "!fwd %d" % fbmag
    elif self.joyFwdBwdPos > 0:
      if self.joyLeftRightPos < 0:
        return "!bwdleft %d %d" % (fbmag, lrmag)
      elif self.joyLeftRightPos > 0:
        return "!bwdright %d %d" % (fbmag, lrmag)
      else:
        return "!bwd %d" % fbmag
    elif self.joyLeftRightPos  < 0:
      return "!left %d" % lrmag
    elif self.joyLeftRightPos > 0:
      return "!right %d" % lrmag

    return "!stop"

class GyroCar:
  def __init__(self):
    self.droid = None
    self.baotooth = None

    self.droid = android.Android()
    #self.droid = android.Android(('192.168.1.6', 33333))
    self.droid.wakeLockAcquireDim()
    #self.droid.generateDtmfTones('123')
    self.connectBluetooth()

    self.roboComm = RoboComm(self.droid, self.baotooth)
    self.gyro = DroidGyroJoystick(self.droid)

  def __del__(self):
    print "Goodbye!"
    if self.droid:
      if self.baotooth:
        self.droid.bluetoothStop(self.baotooth)
      self.droid.wakeLockRelease()

  def connectBluetooth(self):
    uuid = "00001101-0000-1000-8000-00805F9B34FB"
    mac = "98:D3:31:B0:E9:37" # makeblock mac

    self.droid.bluetoothConnect(uuid, mac)
    conns = self.droid.bluetoothActiveConnections()
    if not conns.result:
      print "Android phone failed to link to Baotooth"
    else:
      print "Baotooth connected"
      self.baotooth = conns.result.keys()[0]

    if (self.baotooth):
      self.droid.bluetoothWrite("!beep\n", self.baotooth)

  def run(self):
    # poll gyro, translate to bao commands
    # run forever
    while True:
      self.gyro.updateOrient()
      cmd = self.gyro.getJoyCommand()
      self.roboComm.sendCmd(cmd)
      time.sleep(0.2)

# allow use as a module or standalone script
if __name__ == "__main__":
  gyroCar = GyroCar()
  gyroCar.run()

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

#!/usr/bin/env python

import android

import sys

import time

class RoboComm:

def __init__(self, droid, baotooth):

self.droid = droid

self.baotooth = baotooth

self.lastCommand = None

def sendCmd(self, cmd):

if cmd is None:

return

if "fwd" in cmd or "bwd" in cmd \

or "left" in cmd or "right" in cmd \

or "stop" in cmd:

# don't send redundant movement commands to save data

if self.lastCommand == cmd:

return

print cmd

self.lastCommand = cmd

if self.baotooth:

self.droid.bluetoothWrite(cmd + "\n", self.baotooth)

class DroidGyroJoystick:

def __init__(self, droid):

self.droid = droid

self.orient = None

self.joyFwdBwdPos = 0

self.joyLeftRightPos = 0

self.accelZero = 0.4 # deflection of less than this is treated as no deflection

self.turnZero = 0.3 # deflection of less than this is treated as no deflection

self.minSpeed = 0.4

if self.droid:

self.droid.startSensingTimed(1, 200)

self.updateOrient()

def updateOrient(self):

if self.droid:

self.orient = self.droid.sensorsReadOrientation().result

def getJoyCommand(self):

# translate gyro reading to joystick input

if not self.orient:

return None

if self.orient[0] is None:

return None

turn = self.orient[1] # [1.57=left, 0=stop, -1.57=right]

accel = self.orient[2] # [0=fwd, -1.57=stop, -3.14=bwd]

#if accel > 0 and accel < 0.7:

# # tipping phone too far forward but let's treat as fwd anyway

# accel = 0

if turn > 1.57:

turn = 1.57 # hard left, past horizon = max left

if turn < -1.57:

turn = -1.57 # hard right, past horizon = max right

if accel > 0:

# phone is inverted - send stop signal

return "!stop"

# normalize turn and accel values to [-1.0, 1.0]

turn = (-turn) / 1.57

accel = ((-accel) - 1.57) / 1.57

# filter for neutral pos

if turn > -self.turnZero and turn < self.turnZero:

turn = 0

if accel > -self.accelZero and accel < self.accelZero:

accel = 0

# set min speed

if turn > 0:

turn = max(self.minSpeed, turn)

if turn < 0:

turn = min(-self.minSpeed, turn)

if accel > 0:

accel = max(self.minSpeed, accel)

if accel < 0:

accel = min(-self.minSpeed, accel)

self.joyFwdBwdPos = int(accel * 10)

self.joyLeftRightPos = int(turn * 10)

# decide move cmd based on vectors

fbmag = min(abs(self.joyFwdBwdPos) + 1, 10)

lrmag = min(abs(self.joyLeftRightPos) + 2, 10)

if self.joyFwdBwdPos < 0:

if self.joyLeftRightPos < 0:

return "!fwdleft %d %d" % (fbmag, lrmag)

elif self.joyLeftRightPos > 0:

return "!fwdright %d %d" % (fbmag, lrmag)

else:

return "!fwd %d" % fbmag

elif self.joyFwdBwdPos > 0:

if self.joyLeftRightPos < 0:

return "!bwdleft %d %d" % (fbmag, lrmag)

elif self.joyLeftRightPos > 0:

return "!bwdright %d %d" % (fbmag, lrmag)

else:

return "!bwd %d" % fbmag

elif self.joyLeftRightPos < 0:

return "!left %d" % lrmag

elif self.joyLeftRightPos > 0:

return "!right %d" % lrmag

return "!stop"

class GyroCar:

def __init__(self):

self.droid = None

self.baotooth = None

self.droid = android.Android()

#self.droid = android.Android(('192.168.1.6', 33333))

self.droid.wakeLockAcquireDim()

#self.droid.generateDtmfTones('123')

self.connectBluetooth()

self.roboComm = RoboComm(self.droid, self.baotooth)

self.gyro = DroidGyroJoystick(self.droid)

def __del__(self):

print "Goodbye!"

if self.droid:

if self.baotooth:

self.droid.bluetoothStop(self.baotooth)

self.droid.wakeLockRelease()

def connectBluetooth(self):

uuid = "00001101-0000-1000-8000-00805F9B34FB"

mac = "98:D3:31:B0:E9:37" # makeblock mac

self.droid.bluetoothConnect(uuid, mac)

conns = self.droid.bluetoothActiveConnections()

if not conns.result:

print "Android phone failed to link to Baotooth"

else:

print "Baotooth connected"

self.baotooth = conns.result.keys()[0]

if (self.baotooth):

self.droid.bluetoothWrite("!beep\n", self.baotooth)

def run(self):

# poll gyro, translate to bao commands

# run forever

while True:

self.gyro.updateOrient()

cmd = self.gyro.getJoyCommand()

self.roboComm.sendCmd(cmd)

time.sleep(0.2)

# allow use as a module or standalone script

if __name__ == "__main__":

gyroCar = GyroCar()

gyroCar.run()

If you use the code above, the part that you’ll need to tweak for your own build is the DroidGyroJoystick class. Particularly, the pitch/roll numbers my phone gives lying on one edge may be different from yours. The other things you might want to change are the tuning parameters. For example, I configured a “deadzone” with accelZero and turnZero so that small motions near “centered” position won’t count as joystick inputs.

(If you’re new to SL4A, I show how to get set up, as well as where the android.py in “import android” above comes from, here.)

2. Arduino sketch for the robot car below. Sorry it’s unnecessarily complicated. It’s because it’s code for a 2-in-1 IR or Bluetooth + obstacle-avoidance car. If you connect only an IR sensor to Port 6, it will be IR-controlled. If you connect only a Bluetooth module to Port 7, it will be Bluetooth-controlled. Why did I do such a thing? Because I wanted to be able to switch remotes for my kids just by swapping modules, without uploading sketches.

Anyway, what’s important here is that in Bluetooth mode, it recognizes my silly custom command set (fwd, left, right, bwd, etc). These command strings are how the SL4A Python script on the phone instructs the car what to do, over Bluetooth. The other useful thing is that the Bluetooth commands let me specify the speed, in addition to direction. So the more you push your joystick forward, the faster it’ll go.

#include <Makeblock.h>
#include <Arduino.h>
#include <String.h>
#include <SoftwareSerial.h>
#include <Wire.h>

MeDCMotor MotorL(M1);  
MeDCMotor MotorR(M2);
MeUltrasonicSensor ultrasonic(PORT_3);
MeInfraredReceiver infrared(PORT_6);
MeBluetooth bluetooth(PORT_7);

const int MAXBUFSZ = 128;
char g_lineBuf[MAXBUFSZ]; 
int g_bufReadIdx = 0;

// movement settings
const boolean g_debug = false;
const int g_stepPeriod = 50;
const int g_maxStepsForward = 3000 / g_stepPeriod;
const int g_maxTurnSteps = 3000 / g_stepPeriod;
const int g_minSpeed = 45;
const int g_maxSpeed = 255;
const int g_speedFactor = 23;
const float g_leftTrim = 1.;
const float g_rightTrim = 1.;

// enums
const int LED_PIN = 13;
const int EBRAKE_STOP = 2; // full stop
const int EBRAKE_WAIT = 1; // wait for "Go" signal
const int EBRAKE_GO = 0; // brakes off and GO!
const int MODE_ULTRASONIC = 0;
const int MODE_IR = 1;
const int MODE_BLUETOOTH = 2;
const int MODE_UNKNOWN = 3;
const int ULTRASONIC_INIT_SPEED = 200;

// robo state machine
int g_moveSpeed = ULTRASONIC_INIT_SPEED;
int g_numStepsForward = 0;
int g_numTurnSteps = 0;
boolean g_rightFlag;
int g_ebrake = EBRAKE_STOP;
long g_timeLastBlocked = 0;
uint8_t g_mode = MODE_UNKNOWN;
uint8_t g_lastMode = MODE_UNKNOWN;

void setup()
{
  Serial.begin(9600);
  Serial.println("Software serial on");

  bluetooth.begin(9600);
  Serial.println("Bluetooth on");

  infrared.begin(); 
  Serial.println("Infrared on");

  g_lineBuf[0] = '\0';
  ResetUltrasonic(EBRAKE_STOP);
  pinMode(LED_PIN, OUTPUT); // "obstructed" LED

  Serial.println("Bao ready");
}

void loop()
{
  boolean hasBlue = false;
  boolean hasRed = false;

  if (g_mode == MODE_UNKNOWN)
  {
    // first time - detect if we're in IR or Bluetooth mode
    hasRed = infrared.available() || infrared.buttonState();
    hasBlue = bluetooth.available();

    if (hasRed)
      SwitchMode(MODE_IR);
    if (hasBlue)
      SwitchMode(MODE_BLUETOOTH);
  }
  else if (g_mode == MODE_IR || g_lastMode == MODE_IR)
    hasRed = infrared.available() || infrared.buttonState();
  else if (g_mode == MODE_BLUETOOTH || g_lastMode == MODE_BLUETOOTH)
    hasBlue = bluetooth.available();

  char inDat;
  if (hasBlue)
  {
    ResetUltrasonic(EBRAKE_GO);
    inDat = bluetooth.read();
    Serial.print(inDat);

    readIntoLineBuf(inDat);
    if (cmdLineReady())
    {
      String cmd(g_lineBuf);
      if (g_debug)
        Serial.println("COMMAND " + cmd);
      processCommand(cmd);
    }
  }
  else if (hasRed)
  {
    ResetUltrasonic(EBRAKE_GO);
    inDat = infrared.read();
    switch (inDat)
    {
      case IR_BUTTON_PLUS: 
        Forward(g_moveSpeed);
        break;
      case IR_BUTTON_MINUS:
        Backward(g_moveSpeed);
        break;
      case IR_BUTTON_NEXT:
        TurnRight(g_moveSpeed*2);
        break;
      case IR_BUTTON_PREVIOUS:
        TurnLeft(g_moveSpeed*2);
        break;
      case IR_BUTTON_TEST:
        ForwardAndLeft(g_moveSpeed, g_moveSpeed);
        break;
      case IR_BUTTON_RETURN:
        ForwardAndRight(g_moveSpeed, g_moveSpeed);
        break;
      case IR_BUTTON_9:
        ChangeSpeed(g_speedFactor*9+g_minSpeed);
        break;
      case IR_BUTTON_8:
        ChangeSpeed(g_speedFactor*8+g_minSpeed);
        break;
      case IR_BUTTON_7:
        ChangeSpeed(g_speedFactor*7+g_minSpeed);
        break;
      case IR_BUTTON_6:
        ChangeSpeed(g_speedFactor*6+g_minSpeed);
        break;
      case IR_BUTTON_5:
        ChangeSpeed(g_speedFactor*5+g_minSpeed);
        break;
      case IR_BUTTON_4:
        ChangeSpeed(g_speedFactor*4+g_minSpeed);
        break;
      case IR_BUTTON_3:
        ChangeSpeed(g_speedFactor*3+g_minSpeed);
        break;
      case IR_BUTTON_2:
        ChangeSpeed(g_speedFactor*2+g_minSpeed);
        break;
      case IR_BUTTON_1:
        ChangeSpeed(g_speedFactor*1+g_minSpeed);
        break;
      case IR_BUTTON_POWER:
        buzzerOn();
        delay(100);
        buzzerOff();
        break;
      case IR_BUTTON_MENU:
        if (g_mode != MODE_ULTRASONIC)
        {
          // go ultrasonic
          buzzerOn();
          delay(100);
          buzzerOff();
          delay(100);
          buzzerOn();
          delay(100);
          buzzerOff();
          delay(100);
          buzzerOn();
          delay(300);
          buzzerOff();

          SwitchMode(MODE_ULTRASONIC);
          g_moveSpeed = ULTRASONIC_INIT_SPEED;
        }
        else
        {
          // back to manual remote
          buzzerOn();
          delay(100);
          buzzerOff();
          digitalWrite(LED_PIN, LOW);

          SwitchMode(MODE_IR);
        }

        break;
      default:
        break;
    }
  }
  else
  {
    if (g_mode == MODE_ULTRASONIC
      && millis() % g_stepPeriod == 0)
      doUltrasonicCar();
    else if (g_mode == MODE_IR)
      Stop();
  }
}

bool processCommand(String cmd)
{
  if (cmd == "!beep")
  {
    buzzerOn();
    delay(100);
    buzzerOff();
  }
  else if (cmd.startsWith("!fwd "))
    Forward(getSpeed(cmd, 0));
  else if (cmd.startsWith("!bwd "))
    Backward(getSpeed(cmd, 0));
  else if (cmd.startsWith("!left "))
    TurnLeft(getSpeed(cmd, 0));
  else if (cmd.startsWith("!right "))
    TurnRight(getSpeed(cmd, 0));
  else if (cmd.startsWith("!fwdleft"))
    ForwardAndLeft(getSpeed(cmd, 0), getSpeed(cmd, 1));
  else if (cmd.startsWith("!fwdright"))
    ForwardAndRight(getSpeed(cmd, 0), getSpeed(cmd, 1));
  else if (cmd.startsWith("!bwdleft"))
    BackwardAndTurnLeft(getSpeed(cmd, 0), getSpeed(cmd, 1));
  else if (cmd.startsWith("!bwdright"))
    BackwardAndTurnRight(getSpeed(cmd, 0), getSpeed(cmd, 1));
  else
    Stop();
}

int getSpeed(String cmd, int idx)
{
  int mag = getCmdInt(cmd, idx);
  return g_speedFactor * mag + g_minSpeed;
}

int getCmdInt(String cmd, int idx)
{
  int spaceIdx = cmd.indexOf(' ');
  for (int i=0; i < idx; i++)
    spaceIdx = cmd.indexOf(' ', spaceIdx+1);

  return cmd.substring(spaceIdx+1).toInt();
}

bool cmdLineReady()
{
  if (g_bufReadIdx != 0)
    return false; // still building line

  if (g_lineBuf[0] != '!')
    return false; // not a command line

  return true;
}

void readIntoLineBuf(char c)
{
  if (c == '\n' || c == '\r' || c == '\0')
  {
    // finish line for processing, set ready for next line
    g_bufReadIdx = 0;
    return;
  }

  if (g_bufReadIdx >= MAXBUFSZ - 1)
  {
    // drop overflow bytes
    return;
  }

  g_lineBuf[g_bufReadIdx] = c;
  g_lineBuf[g_bufReadIdx+1] = '\0';
  g_bufReadIdx++;
}

void doUltrasonicCar()
{
  int distance = ultrasonic.distanceCm();
  
  boolean isBlocked = (distance > 0 && distance < 60);
  if (isBlocked)
    g_timeLastBlocked = millis();
  else if (millis() - g_timeLastBlocked < 100)
    isBlocked = true;

  if (isBlocked)
    digitalWrite(LED_PIN, HIGH);
  else
    digitalWrite(LED_PIN, LOW);

  boolean isStuck 
    = (g_numTurnSteps > g_maxTurnSteps
      || g_numStepsForward > g_maxStepsForward);

  if (g_ebrake == EBRAKE_STOP && !isBlocked)
  {
    // /unstuck, ready for go signal
    g_ebrake = EBRAKE_WAIT; 
    return;
  }
  else if (g_ebrake == EBRAKE_WAIT && isBlocked)
  {
    // "Go!"
    ResetUltrasonic(EBRAKE_GO);
    return;
  }
  else if (g_ebrake == EBRAKE_GO && isStuck)
  {
    // stuck -- yank ebrake
    g_ebrake = EBRAKE_STOP;
    Stop();
    return;
  }

  if (g_ebrake != EBRAKE_GO)
  {
    // halt until !blocked and receive "Go" signal
    return;
  }
  
  if (isBlocked)
  {
    // evasive maneuvers!
    randomSeed(analogRead(A4));
    int randnum = random(300);

    if (distance > 30)
    {
      if (randnum > 150 && !g_rightFlag)
        TurnLeft(g_moveSpeed);   
      else
        TurnRight(g_moveSpeed);  
    }
    else
    {
      if (randnum > 150) 
        BackwardAndTurnLeft(g_moveSpeed, g_moveSpeed);
      else 
        BackwardAndTurnRight(g_moveSpeed, g_moveSpeed);
    }
  }
  else
  {
    // ONWARD!
    Forward(g_moveSpeed);
  }
}

void ResetUltrasonic(int brakePos)
{
  g_rightFlag = false;
  g_numStepsForward = 0;
  g_numTurnSteps = 0;
  g_ebrake = brakePos;
  
  if (g_debug && g_mode == MODE_ULTRASONIC)
    Serial.println("Reset");
}

void Stop()
{
  MotorL.stop();
  MotorR.stop();
}

void Forward(int speed)
{
  g_numStepsForward++;
  g_numTurnSteps = 0;
  g_rightFlag = false;

  MotorL.run(speed * g_leftTrim);
  MotorR.run(speed * g_rightTrim);
  
  if (g_debug)
    Serial.println("Forward");
}

void ForwardAndLeft(int fspeed, int lspeed)
{
  g_numStepsForward++;
  g_numTurnSteps++;
  g_rightFlag = false;

  MotorL.run(fspeed - (lspeed / 2));
  MotorR.run(fspeed);
  
  if (g_debug)
    Serial.println("Forward+Left");
}

void ForwardAndRight(int fspeed, int rspeed)
{
  g_numStepsForward++;
  g_numTurnSteps++;
  g_rightFlag = true;

  MotorL.run(fspeed);
  MotorR.run(fspeed - (rspeed / 2));
  
  if (g_debug)
    Serial.println("Forward+Right");
}

void Backward(int speed)
{
  g_rightFlag = false;
  g_numTurnSteps = 0;
  MotorL.run(-speed);
  MotorR.run(-speed);

  if (g_debug)
    Serial.println("Backward");
}

void TurnLeft(int speed)
{
  g_rightFlag = false;
  g_numStepsForward = 0;
  g_numTurnSteps++;

  MotorL.run(-speed / 2);
  MotorR.run(speed / 2);
  
  if (g_debug)
    Serial.println("Left");
}

void TurnRight(int speed)
{
  g_rightFlag = true;
  g_numStepsForward = 0;
  g_numTurnSteps++;

  MotorL.run(speed / 2);
  MotorR.run(-speed / 2);
  
  if (g_debug)
    Serial.println("Right");
}

void BackwardAndTurnLeft(int bspeed, int lspeed)
{
  g_rightFlag = true;
  g_numStepsForward = 0;
  g_numTurnSteps++;

  MotorL.run(-bspeed + (lspeed / 2));
  MotorR.run(-bspeed);

  if (g_debug)
    Serial.println("Backward+Left");
}

void BackwardAndTurnRight(int bspeed, int rspeed)
{
  g_rightFlag = false;
  g_numStepsForward = 0;
  g_numTurnSteps++;

  MotorL.run(-bspeed);
  MotorR.run(-bspeed + (rspeed / 2));

  if (g_debug)
    Serial.println("Backward+Right");
}

void SwitchMode(uint8_t newMode)
{
  g_lastMode = g_mode;
  g_mode = newMode;
}

void ChangeSpeed(int spd)
{
  g_moveSpeed = spd;
}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

#include <Makeblock.h>

#include <Arduino.h>

#include <String.h>

#include <SoftwareSerial.h>

#include <Wire.h>

MeDCMotor MotorL(M1);

MeDCMotor MotorR(M2);

MeUltrasonicSensor ultrasonic(PORT_3);

MeInfraredReceiver infrared(PORT_6);

MeBluetooth bluetooth(PORT_7);

const int MAXBUFSZ = 128;

char g_lineBuf[MAXBUFSZ];

int g_bufReadIdx = 0;

// movement settings

const boolean g_debug = false;

const int g_stepPeriod = 50;

const int g_maxStepsForward = 3000 / g_stepPeriod;

const int g_maxTurnSteps = 3000 / g_stepPeriod;

const int g_minSpeed = 45;

const int g_maxSpeed = 255;

const int g_speedFactor = 23;

const float g_leftTrim = 1.;

const float g_rightTrim = 1.;

// enums

const int LED_PIN = 13;

const int EBRAKE_STOP = 2; // full stop

const int EBRAKE_WAIT = 1; // wait for "Go" signal

const int EBRAKE_GO = 0; // brakes off and GO!

const int MODE_ULTRASONIC = 0;

const int MODE_IR = 1;

const int MODE_BLUETOOTH = 2;

const int MODE_UNKNOWN = 3;

const int ULTRASONIC_INIT_SPEED = 200;

// robo state machine

int g_moveSpeed = ULTRASONIC_INIT_SPEED;

int g_numStepsForward = 0;

int g_numTurnSteps = 0;

boolean g_rightFlag;

int g_ebrake = EBRAKE_STOP;

long g_timeLastBlocked = 0;

uint8_t g_mode = MODE_UNKNOWN;

uint8_t g_lastMode = MODE_UNKNOWN;

void setup()

{

Serial.begin(9600);

Serial.println("Software serial on");

bluetooth.begin(9600);

Serial.println("Bluetooth on");

infrared.begin();

Serial.println("Infrared on");

g_lineBuf[0] = '\0';

ResetUltrasonic(EBRAKE_STOP);

pinMode(LED_PIN, OUTPUT); // "obstructed" LED

Serial.println("Bao ready");

}

void loop()

{

boolean hasBlue = false;

boolean hasRed = false;

if (g_mode == MODE_UNKNOWN)

{

// first time - detect if we're in IR or Bluetooth mode

hasRed = infrared.available() || infrared.buttonState();

hasBlue = bluetooth.available();

if (hasRed)

SwitchMode(MODE_IR);

if (hasBlue)

SwitchMode(MODE_BLUETOOTH);

}

else if (g_mode == MODE_IR || g_lastMode == MODE_IR)

hasRed = infrared.available() || infrared.buttonState();

else if (g_mode == MODE_BLUETOOTH || g_lastMode == MODE_BLUETOOTH)

hasBlue = bluetooth.available();

char inDat;

if (hasBlue)

{

ResetUltrasonic(EBRAKE_GO);

inDat = bluetooth.read();

Serial.print(inDat);

readIntoLineBuf(inDat);

if (cmdLineReady())

{

String cmd(g_lineBuf);

if (g_debug)

Serial.println("COMMAND " + cmd);

processCommand(cmd);

}

else if (hasRed)

{

ResetUltrasonic(EBRAKE_GO);

inDat = infrared.read();

switch (inDat)

{

case IR_BUTTON_PLUS:

Forward(g_moveSpeed);

break;

case IR_BUTTON_MINUS:

Backward(g_moveSpeed);

break;

case IR_BUTTON_NEXT:

TurnRight(g_moveSpeed*2);

break;

case IR_BUTTON_PREVIOUS:

TurnLeft(g_moveSpeed*2);

break;

case IR_BUTTON_TEST:

ForwardAndLeft(g_moveSpeed, g_moveSpeed);

break;

case IR_BUTTON_RETURN:

ForwardAndRight(g_moveSpeed, g_moveSpeed);

break;

case IR_BUTTON_9:

ChangeSpeed(g_speedFactor*9+g_minSpeed);

break;

case IR_BUTTON_8:

ChangeSpeed(g_speedFactor*8+g_minSpeed);

break;

case IR_BUTTON_7:

ChangeSpeed(g_speedFactor*7+g_minSpeed);

break;

case IR_BUTTON_6:

ChangeSpeed(g_speedFactor*6+g_minSpeed);

break;

case IR_BUTTON_5:

ChangeSpeed(g_speedFactor*5+g_minSpeed);

break;

case IR_BUTTON_4:

ChangeSpeed(g_speedFactor*4+g_minSpeed);

break;

case IR_BUTTON_3:

ChangeSpeed(g_speedFactor*3+g_minSpeed);

break;

case IR_BUTTON_2:

ChangeSpeed(g_speedFactor*2+g_minSpeed);

break;

case IR_BUTTON_1:

ChangeSpeed(g_speedFactor*1+g_minSpeed);

break;

case IR_BUTTON_POWER:

buzzerOn();

delay(100);

buzzerOff();

break;

case IR_BUTTON_MENU:

if (g_mode != MODE_ULTRASONIC)

{

// go ultrasonic

buzzerOn();

delay(100);

buzzerOff();

delay(100);

buzzerOn();

delay(100);

buzzerOff();

delay(100);

buzzerOn();

delay(300);

buzzerOff();

SwitchMode(MODE_ULTRASONIC);

g_moveSpeed = ULTRASONIC_INIT_SPEED;

}

else

{

// back to manual remote

buzzerOn();

delay(100);

buzzerOff();

digitalWrite(LED_PIN, LOW);

SwitchMode(MODE_IR);

}

break;

default:

break;

}

else

{

if (g_mode == MODE_ULTRASONIC

&& millis() % g_stepPeriod == 0)

doUltrasonicCar();

else if (g_mode == MODE_IR)

Stop();

}

bool processCommand(String cmd)

{

if (cmd == "!beep")

{

buzzerOn();

delay(100);

buzzerOff();

}

else if (cmd.startsWith("!fwd "))

Forward(getSpeed(cmd, 0));

else if (cmd.startsWith("!bwd "))

Backward(getSpeed(cmd, 0));

else if (cmd.startsWith("!left "))

TurnLeft(getSpeed(cmd, 0));

else if (cmd.startsWith("!right "))

TurnRight(getSpeed(cmd, 0));

else if (cmd.startsWith("!fwdleft"))

ForwardAndLeft(getSpeed(cmd, 0), getSpeed(cmd, 1));

else if (cmd.startsWith("!fwdright"))

ForwardAndRight(getSpeed(cmd, 0), getSpeed(cmd, 1));

else if (cmd.startsWith("!bwdleft"))

BackwardAndTurnLeft(getSpeed(cmd, 0), getSpeed(cmd, 1));

else if (cmd.startsWith("!bwdright"))

BackwardAndTurnRight(getSpeed(cmd, 0), getSpeed(cmd, 1));

else

Stop();

}

int getSpeed(String cmd, int idx)

{

int mag = getCmdInt(cmd, idx);

return g_speedFactor * mag + g_minSpeed;

}

int getCmdInt(String cmd, int idx)

{

int spaceIdx = cmd.indexOf(' ');

for (int i=0; i < idx; i++)

spaceIdx = cmd.indexOf(' ', spaceIdx+1);

return cmd.substring(spaceIdx+1).toInt();

}

bool cmdLineReady()

{

if (g_bufReadIdx != 0)

return false; // still building line

if (g_lineBuf[0] != '!')

return false; // not a command line

return true;

}

void readIntoLineBuf(char c)

{

if (c == '\n' || c == '\r' || c == '\0')

{

// finish line for processing, set ready for next line

g_bufReadIdx = 0;

return;

}

if (g_bufReadIdx >= MAXBUFSZ - 1)

{

// drop overflow bytes

return;

}

g_lineBuf[g_bufReadIdx] = c;

g_lineBuf[g_bufReadIdx+1] = '\0';

g_bufReadIdx++;

}

void doUltrasonicCar()

{

int distance = ultrasonic.distanceCm();

boolean isBlocked = (distance > 0 && distance < 60);

if (isBlocked)

g_timeLastBlocked = millis();

else if (millis() - g_timeLastBlocked < 100)

isBlocked = true;

if (isBlocked)

digitalWrite(LED_PIN, HIGH);

else

digitalWrite(LED_PIN, LOW);

boolean isStuck

= (g_numTurnSteps > g_maxTurnSteps

|| g_numStepsForward > g_maxStepsForward);

if (g_ebrake == EBRAKE_STOP && !isBlocked)

{

// /unstuck, ready for go signal

g_ebrake = EBRAKE_WAIT;

return;

}

else if (g_ebrake == EBRAKE_WAIT && isBlocked)

{

// "Go!"

ResetUltrasonic(EBRAKE_GO);

return;

}

else if (g_ebrake == EBRAKE_GO && isStuck)

{

// stuck -- yank ebrake

g_ebrake = EBRAKE_STOP;

Stop();

return;

}

if (g_ebrake != EBRAKE_GO)

{

// halt until !blocked and receive "Go" signal

return;

}

if (isBlocked)

{

// evasive maneuvers!

randomSeed(analogRead(A4));

int randnum = random(300);

if (distance > 30)

{

if (randnum > 150 && !g_rightFlag)

TurnLeft(g_moveSpeed);

else

TurnRight(g_moveSpeed);

}

else

{

if (randnum > 150)

BackwardAndTurnLeft(g_moveSpeed, g_moveSpeed);

else

BackwardAndTurnRight(g_moveSpeed, g_moveSpeed);

}

else

{

// ONWARD!

Forward(g_moveSpeed);

}

void ResetUltrasonic(int brakePos)

{

g_rightFlag = false;

g_numStepsForward = 0;

g_numTurnSteps = 0;

g_ebrake = brakePos;

if (g_debug && g_mode == MODE_ULTRASONIC)

Serial.println("Reset");

}

void Stop()

{

MotorL.stop();

MotorR.stop();

}

void Forward(int speed)

{

g_numStepsForward++;

g_numTurnSteps = 0;

g_rightFlag = false;

MotorL.run(speed * g_leftTrim);

MotorR.run(speed * g_rightTrim);

if (g_debug)

Serial.println("Forward");

}

void ForwardAndLeft(int fspeed, int lspeed)

{

g_numStepsForward++;

g_numTurnSteps++;

g_rightFlag = false;

MotorL.run(fspeed - (lspeed / 2));

MotorR.run(fspeed);

if (g_debug)

Serial.println("Forward+Left");

}

void ForwardAndRight(int fspeed, int rspeed)

{

g_numStepsForward++;

g_numTurnSteps++;

g_rightFlag = true;

MotorL.run(fspeed);

MotorR.run(fspeed - (rspeed / 2));

if (g_debug)

Serial.println("Forward+Right");

}

void Backward(int speed)

{

g_rightFlag = false;

g_numTurnSteps = 0;

MotorL.run(-speed);

MotorR.run(-speed);

if (g_debug)

Serial.println("Backward");

}

void TurnLeft(int speed)

{

g_rightFlag = false;

g_numStepsForward = 0;

g_numTurnSteps++;

MotorL.run(-speed / 2);

MotorR.run(speed / 2);

if (g_debug)

Serial.println("Left");

}

void TurnRight(int speed)

{

g_rightFlag = true;

g_numStepsForward = 0;

g_numTurnSteps++;

MotorL.run(speed / 2);

MotorR.run(-speed / 2);

if (g_debug)

Serial.println("Right");

}

void BackwardAndTurnLeft(int bspeed, int lspeed)

{

g_rightFlag = true;

g_numStepsForward = 0;

g_numTurnSteps++;

MotorL.run(-bspeed + (lspeed / 2));

MotorR.run(-bspeed);

if (g_debug)

Serial.println("Backward+Left");

}

void BackwardAndTurnRight(int bspeed, int rspeed)

{

g_rightFlag = false;

g_numStepsForward = 0;

g_numTurnSteps++;

MotorL.run(-bspeed);

MotorR.run(-bspeed + (rspeed / 2));

if (g_debug)

Serial.println("Backward+Right");

}

void SwitchMode(uint8_t newMode)

{

g_lastMode = g_mode;

g_mode = newMode;

}

void ChangeSpeed(int spd)

{

g_moveSpeed = spd;

}

P.S. I just installed the WordPress “Crayon Syntax Highlighter” plugin. It prettifies blocks of code within ‹pre› tags, like above. I like it so far.

Secret Science Lab

Surprising adventures with science and DIY tech!

Tag Archives: makeblock starter kit

Arduino Vader “Force Grip” remote car (a.k.a. smartphone virtual wheel)

Teaser: Makeblock Robot Starter Kit Cellbot + Sensors + shxtty Path Tracking