(II) C++ crash examples tutorial using Robotis CM-900 board and IDE (II)

In this post I will try to show one important C++ feature, virtual classes as interfaces, defining a rol that several classes can implement. Also

Here you can download the file with the source code.



[sourcecode language="cpp"]

// C++ crash tutorial with Robotis CM-900.

// First example: http://softwaresouls.com/softwaresouls/

/*
Classes inheritance and interface creation in C++
*/

// Abstract class as Interface for communication device classes http://www.cplusplus.com/doc/tutorial/polymorphism/
class CommunicationDevice
{
public:
virtual void setup(int baudrate=0)=0; // baudrate=0, default parameter in case is not passed any parameter.
//...)=0; is a pure virtual method that convert the class in abstract http://www.cplusplus.com/doc/tutorial/polymorphism/
//      because is not straight usable , a derived classimpllementing the pure virtual methods must be created
virtual void send(char *message)=0;   // default parameter in case is not passed any parameter.

virtual void send(int i)=0; //Method overloading http://www.cplusplus.com/doc/tutorial/functions2/ Same method name with different parameter types

};

class Zigbee : public CommunicationDevice //inherits the interface a should define the methos to be able to create objects.
{
public:
void setup(int baudrate=0);
void send (char *message);
void send(int i);
};

class USB : public CommunicationDevice //inherits the interface a should define the methos to be able to create objects.
{
public:
void setup(int baudrate=0);
void send (char *message);
void send(int i);
};

class Debug {
CommunicationDevice &commDevice;
public:
Debug(CommunicationDevice &aCommDevice) : commDevice(aCommDevice) {}; // member object commDevice is instantiated by reference to avoid object copy
void show(char *message)
{
commDevice.send(message); // the "commDevice"  method called depends on the object passed to the constructor
}

void show(int i)
{
commDevice.send(i);
}
};

void Zigbee::setup(int baudrate)
{
if (baudrate==0)
baudrate=57600; //only changes local copy, not the variable passed as value parameter http://www.cplusplus.com/doc/tutorial/functions2/
Serial2.begin(baudrate);
}

void Zigbee::send(char *message)
{
Serial2.println(message);
}

void Zigbee::send(int i)
{
Serial2.println(i);
}

void USB::setup(int baudrate)
{
SerialUSB.begin();
}

void USB::send(char *message)
{
SerialUSB.println(message);
}

void USB::send(int i)
{
SerialUSB.println(i);
}

Zigbee zigbee;
USB usb;

const byte NumberOfCommsDevices=2;
CommunicationDevice *commsDevices[]={&usb, &zigbee};
//={usb, zigbee};

void setup()
{
//  Individually:

//  zigbee.setup();
//  usb.setup();

//  collectively. using the common Interface "CommunicationDevice"
for (int i=0;i<NumberOfCommsDevices;i++) commsDevices[i]->setup();
delay(2000); // waiting for 2 seconds, let the user activate the monitor/console window (Control+Shift+M).
}

int counter=0;
void loop()
{
++counter;
Debug debug1(usb); // Debug constructor accepts any class inhereting the Interface "CommunicationDevice", Debug(CommunicationDevice &aCommDevice)
debug1.show("Hola"); //debug object will call the method "send" implemented in the object passed to the constructor. In this case "usb.send"

//Showing the counter for each iteration until the 2000th iteration
if (counter <=2000)
debug1.show(counter);
else
{
// Showing the counter every 100 iterations and waiting for 2 seconds
if (counter%100==0) // Operator modulo http://www.cplusplus.com/doc/tutorial/operators/ (returns the remainder)
{
debug1.show(counter);
delay(2000);
}
}
}

[/sourcecode]

Bioloid Workbench Windows C++ examples

This post presents the Windows version of two examples/utilities built, this time, with MS Visual C++ and QT Creator, a great open source IDE and framework.

The first utility has a comand line user interface, being an easy example with only two DLL dependencies to the Visual C++ runtimes.



The second example utility has a graphic user interface created with QT Creator.



Here you can find the bin executables and the projects with the source code.

This is the main function of the first example, the command line:

[sourcecode language="cpp"]
int _tmain(int argc, _TCHAR* argv[])
{
cout << "AXControl_v2_VS_CPP test v0" << endl;

bool quit=false;
MyBasicSystem::BasicSystem mySystem;
UI ui(mySystem);
do
{
ui.showMenu();
int selected=ui.selectOption();
if (selected==ui.OptionQuit)
quit=true;
ui.executeSelectedOption(selected);
}while (!quit);

mySystem.dynamixelCommunication.close();

return 0;
}
[/sourcecode]

[Update] Yesterday I discovered a subtle but ugly bug. Can you spot it? Send an email to if you can't find it but you want to know the danger bug.

It use two classes, the "BasicSystem" (in the library "VS_CPP_AXControl_lib.lib") and a simple "UI" class that receives the input from the user and use the operations offered by the "BasicSystem" class.

For example:

[sourcecode language="cpp"]
int UI::getPosition()
{
int position=0;

do
{
cout << "Type a value between 0 and 1023 to set the AX-12 in that position" << endl; cin>>position;

}while(!validRange(position, 0, 1023));

cout << "Position:" << position << endl;

return position;
}
...
void UI::doSetPosition()
{
int ax12Id=getId();
int position=getPosition();

mySystem.dynamixelCommunication.sendOrder(ax12Id, MyCommunications::GoalPosition,(short) position);
}
[/sourcecode]

And all the cource code:

[sourcecode language="cpp"]
/*------------------------------------------------------------------------------*\
* This source file is subject to the GPLv3 license that is bundled with this *
* package in the file COPYING. *
* It is also available through the world-wide-web at this URL: *
* http://www.gnu.org/licenses/gpl-3.0.txt *
* If you did not receive a copy of the license and are unable to obtain it *
* through the world-wide-web, please send an email to *
* siempre.aprendiendo@gmail.com so we can send you a copy immediately. *
* *
* @category Robotics *
* @copyright Copyright (c) 2011 Jose Cortes (http://www.siempreaprendiendo.es) *
* @license http://www.gnu.org/licenses/gpl-3.0.txt GNU v3 Licence *
* *
\*------------------------------------------------------------------------------*/

#include "stdafx.h"
#include
#include "BasicSystem.h"
#include "Util.h"

using namespace std;

class UI
{
public:
static const int OptionQuit=8;

UI(MyBasicSystem::BasicSystem& aMySystem) : mySystem(aMySystem) {}

void showMenu();
int selectOption();
bool executeSelectedOption(int selected);
void doBeep();

private:
MyBasicSystem::BasicSystem mySystem;

static const int OptionSetLEDOnOff=1;
static const int OptionQueryAX12=2;
static const int OptionMoveAX12=3;
static const int OptionTorqueAX12=4;
static const int OptionQuerySensor=5;
static const int OptionShowMenu=6;
static const int OptionBeep=7;

static const int MinOption=OptionSetLEDOnOff;
static const int MaxOption=OptionQuit;

bool validRange(int value, int MinValue, int MaxValue);
bool nonValidOption(int option);
int getPosition();
int getId();
int getSensorPort();
void doGetPosition();
void doSetPosition();
void doQuerySensor();
void doSetLEDOnOff();
void doSetTorqueOnOff();

};

void UI::showMenu()
{
cout << "V02" << endl;

cout << OptionSetLEDOnOff << ".- Toggle AX-12 LED" << endl;
cout << OptionQueryAX12 << ".- Query AX-12" << endl;
cout << OptionMoveAX12 << ".- Move AX-12" << endl;
cout << OptionTorqueAX12 << ".- Torque AX-12" << endl;
cout << OptionQuerySensor << ".- Query CM-510 sensor" << endl;
cout << OptionShowMenu << ".- Show menu" << endl;
cout << OptionBeep << ".- Beep" << endl;
cout << OptionQuit << ".- Quit" << endl;
}

bool UI::nonValidOption(int option)
{
return (optionMaxOption);
}

int UI::selectOption()
{
int option=-1;

while (nonValidOption(option))
{
cout << "Select option (" << MinOption << "-" << MaxOption << ")" << endl; cin >> option;
if (nonValidOption(option))
{
cout << endl;
cout << endl;
cout << "(" << option << ") is NOT a valid option" << endl; } } return option; } bool UI::validRange(int value, int MinValue, int MaxValue) { return (value>=MinValue && value<=MaxValue);
}

int UI::getPosition()
{
int position=0;

do
{
cout << "Type a value between 0 and 1023 to set the AX-12 in that position" << endl; cin>>position;

}while(!validRange(position, 0, 1023));

cout << "Position:" << position << endl; return position; } int UI::getId() { int ax12Id=1; do { puts ("Type the ID of the AX-12 to use, a value between 1 and 18, "); cin >> ax12Id;

}while(!validRange(ax12Id, 1, 18));

cout << "AX12 Id:" << ax12Id << endl; return ax12Id; } int UI::getSensorPort() { int sensorPort=1; do { puts ("Type the sensor Port to read, a value between 1 and 6, "); cin >> sensorPort;

}while(!validRange(sensorPort, 1, 6));

cout << "Sensor Port number:" << sensorPort << endl;

return sensorPort;
}

void UI::doBeep()
{
cout << "Beep" << endl;
mySystem.dynamixelCommunication.sendOrder(100, AXS1_Buzzer, (byte) DO, (short) 500);
Sleep (2);
mySystem.dynamixelCommunication.sendOrder(200, MyCommunications::Beep, (byte) 5);
}

void UI::doGetPosition()
{
int ax12Id=getId();

int position = mySystem.dynamixelCommunication.readValue(ax12Id, MyCommunications::PresentPosition);
cout << "the position is: [" << position << "] " << endl << endl << endl;
}

void UI::doSetPosition()
{
int ax12Id=getId();
int position=getPosition();

mySystem.dynamixelCommunication.sendOrder(ax12Id, MyCommunications::GoalPosition,(short) position);
}

void UI::doQuerySensor()
{
int sensorPort=getSensorPort();

int value=mySystem.dynamixelCommunication.readSensorValue (200, ReadCM510SensorRaw, sensorPort);
cout << "the sensor reads: [" << value << "] " << endl << endl << endl;
}

void UI::doSetLEDOnOff()
{
byte lByte=0, hByte=0;
int ledValue;

int ax12Id=getId();

ledValue=mySystem.dynamixelCommunication.readValue(ax12Id, MyCommunications::LED);
Hex::toHexHLConversion(ledValue, hByte, lByte);

bool onOff=false;
if (lByte!=0)
onOff=true;

cout << "The LED is: [" << (onOff?"on":"off") << "], putting it: [" << (onOff?"Off":"on") << "] " << endl << endl << endl;
mySystem.dynamixelCommunication.sendOrder(ax12Id, MyCommunications::LED, byte(onOff?0:1));
}

void UI::doSetTorqueOnOff()
{
byte lByte=0, hByte=0;
int ax12Id=getId();

int torque=mySystem.dynamixelCommunication.readValue(ax12Id, MyCommunications::Torque);
Hex::toHexHLConversion(torque, hByte, lByte);
bool onOff=(lByte!=0?true:false);

cout << "The Torque is: [" << (onOff?"on":"off") << "], putting it: [" << (onOff?"Off":"on") << "] " << endl << endl << endl;

mySystem.dynamixelCommunication.sendOrder(ax12Id, MyCommunications::Torque,(byte) (onOff?0:1));
}

bool UI::executeSelectedOption(int option)
{
bool isOk=true;
cout << endl;
cout << endl;

cout << "Selected option: [" << option << "] " << endl; switch(option) { case OptionSetLEDOnOff: doSetLEDOnOff(); break; case OptionQueryAX12: doGetPosition(); break; case OptionMoveAX12: doSetPosition(); break; case OptionTorqueAX12: doSetTorqueOnOff(); break; case OptionQuerySensor: doQuerySensor(); break; case OptionShowMenu: showMenu(); break; case OptionBeep: doBeep(); break; } return isOk; } [/sourcecode]

The code for the Qt version is more complex, but as an example, the same operation that the example for the command line:

[sourcecode language="cpp"] int MainWindow::getAX12_1_Id() { // Get the value from the edit control for the first AX-12 QString qStr=ui->SB_AX12_1_ID->text();
int id=Util::convertToInt(qStr.toStdString());

return id;
}
...
void MainWindow::on_B_AX12_1_SET_POS_clicked()
{
int id = getAX12_1_Id();

// Get the target position from the UI edit control as string and a convert it to int
short position= ui->SB_AX12_1_POS->text().toInt();

// Send the order to the AX-12 with the "id" to go to "position"
pDynComm->sendOrder(id, MyCommunications::GoalPosition,position);
}
[/sourcecode]

Arduino C++ crash examples tutorial using Duemilanove (I)

This is the first example in a serie of cheap (absolutely free and cheap) articles to get some basic and practical C++ knowledge. It will references the great explanations provided at www.cplusplus.com C++ tutorial. Using Arduino Duemilanove (well, really it's a Funduino).

Here you can download The file with the code, and you can find links to a lot of free tutorials, courses and books to learn C++ here.


[sourcecode language="cpp"]
// C++ crash tutorial with Arduino Duemilanove.

// First example: http://softwaresouls.com/softwaresouls/2013/06/23/c-crash-tutorial-using-robotis-cm-900-board-and-ide-i/

/*
Hello World shows messages on construction and destruction
Also it lets you to salute.
Showing always its assigned identifiction number MyId
*/
class HelloWorld
{
private:
int myId; //Object identification num ber

public:

// class constructor http://www.cplusplus.com/doc/tutorial/classes/
HelloWorld(char *message, byte id)
{
myId=id;
Serial.print(message);
printId();
}

// class destructor http://www.cplusplus.com/doc/tutorial/classes/
~HelloWorld()
{
Serial.print ("Destructing object: ");
printId();
}

void printId()
{
Serial.print(" ID:");
Serial.println(myId);
Serial.println(" ");
}

void Salute(char *name)
{
Serial.print("Hi!, ");
Serial.println(name);
Serial.print("Regards from object: ");
printId();
}
};

/*
void setup() function it's only executed one time at the start of the execution.
It is called from a hidden main() function in the Ronbotis CM-900 IDE core.

\ROBOTIS-v0.9.9\hardware\robotis\cores\robotis\main.cpp
Note: "while (1)" is a forevr loop ( http://www.cplusplus.com/doc/tutorial/control ):

(Basic structure http://www.cplusplus.com/doc/tutorial/program_structure/)

int main(void) {
setup();

while (1) {
loop();
}
return 0;
}
*/
void setup()
{
Serial.begin(57600); //initialize serial USB connection
delay(3000); //We will wait 3 seconds, let the user open (Control+Shift+M) the Monitor serial console
}

//We will not see neither the construction nor the destruction of this global object because serial port it's not still initiated
HelloWorld hw0("construction object", 0); //Object construction http://www.cplusplus.com/doc/tutorial/classes/

// A counter to see progress and launch events
int iterationCounter=0; //An integer variable to count iterations http://www.cplusplus.com/doc/tutorial/variables

// void loop() will be executing the sentences it contains while CM-900 is on.
void loop()
{
// Lets's show only the first 5 iterations http://www.cplusplus.com/doc/tutorial/control/
if (iterationCounter<5)
{
Serial.print("starting iteration #");
Serial.println(++iterationCounter); // firts, iterationCounter is incremented and then printed

// We will see the consttructiona and destruction messages from this local (inside the loop function) object. Object construction http://www.cplusplus.com/doc/tutorial/classes/
HelloWorld hw1("constructing object", 1);
hw1.Salute("Joe");

if (iterationCounter==3)
{
// We will see the consttruction and destruction messages from this local (inside the "if" block inside the "loop" function) object. Objet construction http://www.cplusplus.com/doc/tutorial/classes/
HelloWorld hw2("constructing object", 2);
hw2.Salute("Jones");
} // Objet hw2 destruction http://www.cplusplus.com/doc/tutorial/classes/

//Let's show that object hw0 is alive
hw0.Salute("Pepe");

Serial.print("ending iteration #");
Serial.println(iterationCounter++); // first cpunter is printed, then incremented.
} // Objet hw1 destruction http://www.cplusplus.com/doc/tutorial/classes/
} // Program end. Objet hw0 destruction http://www.cplusplus.com/doc/tutorial/classes/
[/sourcecode]

(I) Robotis CM-900 C++ crash examples tutorial

This is the first example in a serie of cheap (absolutely free and cheap) articles to get some basic and practical C++ knowledge. It will references the great explanations provided at www.cplusplus.com C++ tutorial. And using the very cheap and opensource (about 20$/€) Robotis 32 bits microcontroller board CM-900 (STM32 based) and Arduino based IDE.

Here you can download the file with the code, and you can find links to a lot of free tutorials, courses and books to learn C++ here.


[sourcecode language="cpp"]
// C++ crash tutorial with Robotis CM-900.

// First example: http://softwaresouls.com/softwaresouls/2013/06/23/c-crash-tutorial-using-robotis-cm-900-board-and-ide-i/

/*
Hello World shows messages on construction and destruction
Also it lets you to salute.
Showing always its assigned identifiction number MyId
*/
class HelloWorld
{
private:
int myId; //Object identification num ber

public:

// class constructor http://www.cplusplus.com/doc/tutorial/classes/
HelloWorld(char *message, byte id)
{
myId=id;
SerialUSB.print(message);
printId();
}

// class destructor http://www.cplusplus.com/doc/tutorial/classes/
~HelloWorld()
{
SerialUSB.print ("Destructing object: ");
printId();
}

void printId()
{
SerialUSB.print(" ID:");
SerialUSB.println(myId);
SerialUSB.println(" ");
}

void Salute(char *name)
{
SerialUSB.print("Hi!, ");
SerialUSB.println(name);
SerialUSB.print("Regards from object: ");
printId();
}
};

/*
void setup() function it's only executed one time at the start of the execution.
It is called from a hidden main() function in the Ronbotis CM-900 IDE core.

\ROBOTIS-v0.9.9\hardware\robotis\cores\robotis\main.cpp
Note: "while (1)" is a forevr loop ( http://www.cplusplus.com/doc/tutorial/control ):

(Basic structure http://www.cplusplus.com/doc/tutorial/program_structure/)

int main(void) {
setup();

while (1) {
loop();
}
return 0;
}
*/
void setup()
{
SerialUSB.begin(); //initialize serial USB connection
delay(3000); //We will wait 3 seconds, let the user open (Control+Shift+M) the Monitor serial console
}

//We will not see neither the construction nor the destruction of this global object because serial port it's not still initiated
HelloWorld hw0("construction object", 0); //Object construction http://www.cplusplus.com/doc/tutorial/classes/

// A counter to see progress and launch events
int iterationCounter=0; //An integer variable to count iterations http://www.cplusplus.com/doc/tutorial/variables

// void loop() will be executing the sentences it contains while CM-900 is on.
void loop()
{
// Lets's show only the first 5 iterations http://www.cplusplus.com/doc/tutorial/control/
if (iterationCounter<5)
{
SerialUSB.print("starting iteration #");
SerialUSB.println(++iterationCounter); // firts, iterationCounter is incremented and then printed

// We will see the consttruction and destruction messages from this local (inside the loop function) object. Object construction http://www.cplusplus.com/doc/tutorial/classes/
HelloWorld hw1("constructing object", 1);
hw1.Salute("Joe");

if (iterationCounter==3)
{
// We will see the consttructiona and destruction messages from this local (inside the "if" block inside the "loop" function) object. Objet construction http://www.cplusplus.com/doc/tutorial/classes/
HelloWorld hw2("constructing object", 2);
hw2.Salute("Jones");
} // Objet hw2 destruction http://www.cplusplus.com/doc/tutorial/classes/

//Let's show that object hw0 is alive
hw0.Salute("Pepe");

SerialUSB.print("ending iteration #");
SerialUSB.println(iterationCounter++); // first cpunter is printed, then incremented.
} // Objet hw1 destruction http://www.cplusplus.com/doc/tutorial/classes/
} // Program end. Objet hw0 destruction http://www.cplusplus.com/doc/tutorial/classes/
[/sourcecode]

Robotis CM-900 in Toss Mode and querying connected sensors

CM-900 is a very cheap and tiny Robotis Dynamixel controller based in the STM32 ARM 32 bits microcontroller. Here you can find several links to documents.



I think it's ideal as a controller managed with, for example, a Raspberry Pi or a Pandaboard, so I have created a program which can be managed externally to control Dynamixel items (AX-12, AX-S1), Toss Mode, and sensors connected to the CM-900 with a simple protocol similar but simpler than the Dynamixel protocol:

[Headers] [ID] [Command code] [Nº Params] [Param1] [Param2] [ParamN]

Toss Mode works like USB2Dynamixel, but with this program in addition you can get sensor vales.

Toss Mode was a software feature, at least since CM-5, which allows you to use the elements connected to the controller from another device, usually a more powerful computer. What it receives from the USB or serial is sent to the Dynamixel bus, and whatever it receives from Dynamyxel bus is sent to the serial or USB connection.

Example for blinking twice: { 0xFF, 0xFF, 90, 1, 1, 2 }

Headers: 0xFF 0xFF

ID: 90

Command code: 1

Number of parameters: 1

Parameter 1: 2

Example for reading ultrasonic sensor (HC-SR04) : { 0xFF, 0xFF, 90, 2, 0 }

[sourcecode language="CPP"]

void MainWindow::testCM900_Sensor_US()
{
const int size=5;
byte buffer2[size] = { 0xFF, 0xFF, 90, 2, 0 };
pDynComm->rawWrite(buffer2, size);
}
[/sourcecode]

[caption id="attachment_1753" align="alignleft" width="320"] Ultrasonic sensor hc-sr04[/caption]

And here the file with the code for Robotis CM-9 IDE version 0.9.9. You also need to copy Prof. Mason library for ultrasonic sensor to CM 900 IDE libraries folder. Althought it i still a beta version, I think it works ok. Asigning true to these variables, the messages for debugging are sent either to USB connection o Serial2 (connecting Zigbee is the easy option):

[sourcecode language="CPP"]
bool debugOutputSerial2On=true;
bool debugOutputOn=false;
[/sourcecode]

Arduino LCD 1602 (16x2) display

Another little pearl from www.dx.com is the Arduino compatible LCD 1602 (16 characters each of the 2 rows) display:



It's really cheap, 6$/4.5€, works very fine and it's easy to use! I will use as a handy debug display and little dashboard (it has 6 buttons at the bottom) while on field robots debugging, but this wioll be a near post with the sourcecode (that also will be a order receiver to program a Rapsberry Pi to control a robot using and Arduino Funduino Duemilanove.)



Two easy examples from the Arduino IDE wondeful examples, it's important that you notice that the initialization sentence should be:

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

The hello world
[sourcecode language="C"]
/*
LiquidCrystal Library - Hello World

Demonstrates the use a 16x2 LCD display. The LiquidCrystal
library works with all LCD displays that are compatible with the
Hitachi HD44780 driver. There are many of them out there, and you
can usually tell them by the 16-pin interface.

This sketch prints "Hello World!" to the LCD
and shows the time.

The circuit:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)

Library originally added 18 Apr 2008
by David A. Mellis
library modified 5 Jul 2009
by Limor Fried (http://www.ladyada.net)
example added 9 Jul 2009
by Tom Igoe
modified 22 Nov 2010
by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/LiquidCrystal
*/

// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
//LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("Te, amo, Nuriitaa!");
}

void loop() {
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of seconds since reset:
lcd.print(millis()/1000);
}
[/sourcecode]

Testing buttons
[sourcecode language="C"]
//Sample using LiquidCrystal library
#include <LiquidCrystal.h>

/*******************************************************

This program will test the LCD panel and the buttons
Mark Bramwell, July 2010

********************************************************/

// select the pins used on the LCD panel
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

// define some values used by the panel and buttons
int lcd_key = 0;
int adc_key_in = 0;
#define btnRIGHT 0
#define btnUP 1
#define btnDOWN 2
#define btnLEFT 3
#define btnSELECT 4
#define btnNONE 5

// read the buttons
int read_LCD_buttons()
{
adc_key_in = analogRead(0); // read the value from the sensor
// my buttons when read are centered at these valies: 0, 144, 329, 504, 741
// we add approx 50 to those values and check to see if we are close
if (adc_key_in > 1000) return btnNONE; // We make this the 1st option for speed reasons since it will be the most likely result
if (adc_key_in < 50) return btnRIGHT;
if (adc_key_in < 195) return btnUP;
if (adc_key_in < 380) return btnDOWN;
if (adc_key_in < 555) return btnLEFT;
if (adc_key_in < 790) return btnSELECT;
return btnNONE; // when all others fail, return this...
}

void setup()
{
lcd.begin(16, 2); // start the library
lcd.setCursor(0,0);
lcd.print("Push the buttons"); // print a simple message
}

void loop()
{
lcd.setCursor(9,1); // move cursor to second line "1" and 9 spaces over
lcd.print(millis()/1000); // display seconds elapsed since power-up


lcd.setCursor(0,1); // move to the begining of the second line
lcd_key = read_LCD_buttons(); // read the buttons

switch (lcd_key) // depending on which button was pushed, we perform an action
{
case btnRIGHT:
{
lcd.print("RIGHT ");
break;
}
case btnLEFT:
{
lcd.print("LEFT ");
break;
}
case btnUP:
{
lcd.print("UP ");
break;
}
case btnDOWN:
{
lcd.print("DOWN ");
break;
}
case btnSELECT:
{
lcd.print("SELECT");
break;
}
case btnNONE:
{
lcd.print("NONE ");
break;
}
}
}
[/sourcecode]

Robotis CM-900 as a tosser for Dynamixel commands

CM-900 is really tiny and cheap, so is perfect to use as communication bridge between any computer (Raspberry Pi, Pandaboard, etc. included, of course) and the Dynamixel bus. Whatever it receives from the Serial USB (usually commands and queries) is sent to the Dynamixel bus, and what it receives from the Dynamixel bus is sent to the SerialUSB (usually answers)

Here is the source code of the little program for CM-900 IDE:

[sourcecode language="C"]
int counter;
bool onlyOnceHappened;

void blinkOnce()
{
digitalWrite(BOARD_LED_PIN, LOW);
delay_us(100);
digitalWrite(BOARD_LED_PIN, HIGH);
}

void setup()
{
pinMode(BOARD_LED_PIN, OUTPUT);

onlyOnceHappened=false;
counter=0;

//USB Serial initialize
SerialUSB.begin();
// SerialUSB.attachInterrupt(USBDataReceived);
//DXL initialize
Dxl.begin(1);
}

byte aByte=0;
uint8 aUint8;

void loop()
{
// SerialUSB.println (counter++);

if (onlyOnceHappened==false)
{
blinkOnce();
onlyOnceHappened=true;
delay (3000); //Some time to the user to activate the monitor/console
SerialUSB.println ("v1.1.1 Orders receiver started");
}

if (SerialUSB.available())
{
aUint8=SerialUSB.read();
blinkOnce();
Dxl.writeRaw(aUint8);
// delay(20);
}

if (Dxl.available())
{
aByte=Dxl.readRaw();
blinkOnce();
SerialUSB.write(aByte);
// delay(20);
}
}

[/sourcecode]

Here the file.

In the next post I will include an improved version that could read sensors connected to the CM-900, "expanding" the Dynamixel protocol.