Pololu Robotics & Electronics
Menu
My account Comments or questions? About Pololu Contact Ordering information Distributors

Pololu Forum

Arduino and Micro Serial Servo Controller


#1

I used the Micro Serial Servo Controller (MSSC) with Arduino
to build three dancing matryoshkas. The response
of the MSSC is satisfyingly quick to synchronize
the puppets to a tune (I took a Russian punk rock song)

To create the beat I used an external pushbutton connected
to an input of the Arduino. Ideally, this should create an
interrupt on the Arduino, but there is a problem
in connection with the library SoftwareSerial.h.
Once you use Arduino interrupts the timing does
not work properly any more and SoftwareSerial.h
cannot produce correct serial bytes.
I put a note about it on the arduino forum, maybe it will be solved
later.
arduino.cc/cgi-bin/yabb2/YaB … 8516/13#13

To overcome this problem I used an external Flip-Flop which
catches the signal from the button and must be reset from
Arduino once it took the signal.
Furthermore to turn the puppets to back and front I used
three lever switches.

I do not recommend using the regular Pins 0 and 1 used for serial
communication. You need them usually for debugging and controlling
your program. Better is to use the software serial. You can use the
following code framework

/*
  Pololu Template Program
  It allows to set servos interactively. 

  by Hannes Hassler 
  
  based on examples by Tom Igoe, David Mellis and Heather Dewey-Hagborg
  and on the contribution from Adam (nexisnet) in Thread
  'https://forum.pololu.com/t/arduino-pololu-micro-serial-8-servo-controller/613/1&highlight=arduino'
  discussing mostly between Adam, Phil and Zagrophyte
  
  written: 20 Oct 2008


*/


#include <SoftwareSerial.h>


#define reset 7
#define rxPin 6
#define txPin 5


// set up a new serial port
SoftwareSerial mySerial =  SoftwareSerial(rxPin, txPin);


void setup()  {
  // define pin modes for tx, rx, led pins:
  pinMode(rxPin, INPUT);
  pinMode(txPin, OUTPUT);
  pinMode(reset, OUTPUT);  
  
  resetPololu();
  
  mySerial.begin(9600);
  
  Serial.begin(9600);
}



void resetPololu() {
      digitalWrite(reset, LOW);
      delay(100);
      digitalWrite(reset,HIGH);
}


void send2Pololu(int servo, int angle) {
  
  //maxRightAngle 4850
  //minLeftAngle  1100
  
  unsigned char buff[6];

  unsigned int temp;
  unsigned char pos_hi,pos_low;

  //Convert the angle data into two 7-bit bytes
  temp=angle&0x1f80;
  pos_hi=temp>>7;
  pos_low=angle & 0x7f;

  //Construct a Pololu Protocol command sentence
  buff[0]=0x80; //start byte
  buff[1]=0x01; //device id
  buff[2]=0x04; //command number
  buff[3]=servo; //servo number
  buff[4]=pos_hi; //data1
  buff[5]=pos_low; //data2
  
  
  //Send the command to the servo controller
  for(int i=0;i<6;i++){
   mySerial.print(buff[i]);  
  }
  
  
  
  
}

 


void loop() {
  
  
  static int v = 0;  
  static int servo = 0;
  static int angle = 0;
  static char ch;
  
  static int left=1000;
  static int right=3000;
  
  if (Serial.available()) {    
    
      ch = Serial.read();
    

    /*
    To set a specific servo interactively you
    can use the folling scheme (type in the Serial port entry)
    to select servo No 3, type            : 3s  
    to set servo angle to 2000            : 2000a
    to activate the servo respectively    : d
    set selected servo to its left value  : l
    set left value to 1100                : 1100L
    set selected servo to its right value : r
    set right value to 4500               : 4500R
    reset Pololu                          : z 
    (reset pin 7 must be connected to reset pin of Pololu)
    */
    
    switch(ch) {
      case '0'...'9':
        v = v * 10 + ch - '0';
        break;
      case 's':
       Serial.print("servo:");
       Serial.println(v);
       servo=v;
       v = 0;
       break;
      case 'a':
       Serial.print("angle:");
       Serial.println(v);
       angle=v;
       v = 0;
       break;
       case 'd':
       Serial.print("set servo No:");
       Serial.print(servo);
       Serial.print(" angle:");
       Serial.println(angle);
       send2Pololu(servo, angle);
       break;
       case 'l':
       send2Pololu(servo,left);      
       break;
       case 'L':
       left=v;
       Serial.print("left:");
       Serial.println(v);
       v=0;
       break;
       case 'r':
       send2Pololu(servo,right);      
       break;
       case 'R':
       right=v;
       Serial.print("right:");
       Serial.println(v);
       v=0;
       break;
       case 'z':
       resetPololu();      
       break;
    } 
  }  
}

Micro Serial Servo Controller + Xbee
#2

Hello.

That’s very cool, thank you for sharing your project with us!

- Ben


#3

This is too cool… i love it man! thanks for sharing your project to us…