Goodmorning everyone,
I am trying to program a 4DOF robotic arm (using 4 servo motors). I would like to move the servos using an Android app, by means of bluetooth.
I developed the app, in whose interface there are 7 buttons (Up, Down, Left, Rght, Forward, Backward, Save) and a field in which you can type using the keyboard (I attach an image for clarity).
This is the code:
#include <SoftwareSerial.h>
SoftwareSerial BT(10,11); // 10 RX, 11 TX
#include <Servo.h>
char DataBT = ' ';
Servo servo01;
byte pos01_i = 90, pos01_o;
int servo01SP[50]; // for storing positions/steps
int index = 0;
#define ANGLE_STEP 10 // 10 degrees step
void setup() {
Serial.begin(9600);
BT.begin(9600);
Serial.println("");
Serial.println("Starting Control ...");
servo01.attach(12);
servo01.write(pos01_i);
servo01SP[0] = 90; // Initial position
}
void loop() {
if (BT.available()){
DataBT = BT.read();
Serial.println(DataBT);
switch (DataBT){
case('U'):
Serial.println("UP");
if (pos01_i <= 180 - ANGLE_STEP){
pos01_o = pos01_i + ANGLE_STEP;
delay(20);
break;
}
case ('D'):
Serial.println("DOWN");
if (pos01_i >= ANGLE_STEP){
pos01_o = pos01_i - ANGLE_STEP;
delay(20);
break;
}
}
servo01.write(pos01_o);
Serial.println(pos01_o);
pos01_i = pos01_o;
delay(20);
}
}
So far, I tried to manage only Up button (which sens 'U' via bluetooth to arduino) and Down (which sens 'D'), which would move the servo intended for vertical arm movements. That code works quite good, although the app crashes sometimes, but I still can't figure the reason out.
Seen that, what I would like to do now is: once I have moved the servo and reached a particular position, I'd like to save the position of the motor into an array. In order to allow multiple positions saving, after Save button is pressed, I want Arduino to wait for another input from the bluetooth (so that, it would wait for another button to be clicked from the app or for something typed into the dedicated bar from keyboard) that defines the position within the array, in which I save the servo position (eg: I type '2' into the dedicated app bar and Arduino, which is waiting for an input, receiving it, saves the last servo position into the array servo01pos[2]).
What I am not able to do is to make Arduino wait for a new bluetooth input when it receives 'S'. I tried several ways and searched in various forums, but I haven't yet been able to solve the problem.
This is the code of one of the many attempts made:
#include <SoftwareSerial.h>
SoftwareSerial bluetooth(10, 11); //BlueTooth RX ,TX
#include <Servo.h>
unsigned long timestampSend = 0; // BT Write wait period
String readString;
Servo servo01;
byte pos01_i = 90, pos01_o = 90;
#define ANGLE_STEP 10 // 10 degrees step
int servo01pos[50];
void setup()
{
Serial.begin(9600);
bluetooth.begin(9600);
delay(1000);
Serial.print("Ready ...");
Serial.print ("\n");
servo01.attach(12);
servo01.write(pos01_i);
}
void loop()
{
if (millis() >= timestampSend + (1000)) // sending data over BT every 500mS
{
while (bluetooth.available())
{
delay(10);
char data = bluetooth.read();
readString += data;
if (readString.length() > 0) {
Serial.println("Received Value: " + readString);
readString = ""; //clears variable for new input
}
switch(data){
case ('S'): //SAVE
while (bluetooth.available()){
bluetooth.listen();
char button = bluetooth.read(); // the number entered is the button (position) we want to save
Serial.println("SAVING POSITIONS ...");
if (button == '0'){
servo01pos[0] = pos01_o;
} else if (button == '1'){
servo01pos[1] = pos01_o;
} else if (button == '2'){
servo01pos[2] = pos01_o;
}
servo01.write(pos01_o);
Serial.println(pos01_o);
Serial.println(servo01pos[1]);
}
break;
case('U'):
Serial.println("UP");
if (pos01_i <= 180 - ANGLE_STEP){
pos01_o = pos01_i + ANGLE_STEP;
servo01.write(pos01_o);
delay(20);
}
break;
case ('D'):
Serial.println("DOWN");
if (pos01_i >= ANGLE_STEP){
pos01_o = pos01_i - ANGLE_STEP;
servo01.write(pos01_o);
delay(20);
}
break;
}
delay(20);
timestampSend = millis();
}
}
}
I hope I've been sufficiently clear. I apologize for the lack of synthesis.
Thanks in advance to who will answer me.
Giammarco
