I’m working on a 4 wheeled robot driven with stepper motors. I have a Raspberry Pi that sends a random (based on input image) pulse count to the Arduino board serially and then steps that amount. I’m using an Arduino CNC board to drive all 4 stepper motors, just FYI. My problem is that currently my steppers will not simultaneously move. I’ve read over the documentation for the AccelStepper library pretty well and tried some of the example code with no luck. I have a lot of function/ parsing code prior to the actual stepper code. It’s almost at the end, the function called ‘yMovement’. Currently, the int value is received then yStepper moves, then yStepper1 moves after.
My updated code now makes them move simultaneously but the done command does not behave as before.
#include <AccelStepper.h>
const int stepperCount = 4;
AccelStepper FLStepper(AccelStepper::FULL2WIRE, 2, 5);
AccelStepper FRStepper(AccelStepper::FULL2WIRE, 3, 6);
AccelStepper BRStepper(AccelStepper::FULL2WIRE, 4, 7);
AccelStepper BLStepper(AccelStepper::FULL2WIRE, 12, 13);
bool movementComplete = false;
// defines pins numbers
//Front left wheel
const int stepX = 2;
const int dirX = 5;
//Front right wheel
const int stepY = 3;
const int dirY = 6;
//Back left wheel
const int stepZ = 4;
const int dirZ = 7;
//Back right wheel
const int stepA = 12;
const int dirA = 13;
const int enPin = 8;
char split = ':'; //this is the character that would be used for seperating the different parts of your commands
//the syntax for commands would be: command:value1:value2
int listSize = 5; //the amount of commands in the list
String commands[] = {"hello", "add", "sub", "YMOV", "XMOV"}; //the list of every command name
void setup()
{
Serial.begin(115200); //sets the data transfer rate for the serial interface
//9600 is good for basic testing, but should be as high
//as possible for both devices.
FRStepper.setMaxSpeed(500);
FRStepper.setAcceleration(400);
BRStepper.setMaxSpeed(500);
BRStepper.setAcceleration(400);
FLStepper.setMaxSpeed(500);
FLStepper.setAcceleration(400);
BLStepper.setMaxSpeed(500);
BLStepper.setAcceleration(400);
pinMode(stepX, OUTPUT);
pinMode(dirX, OUTPUT);
pinMode(stepY, OUTPUT);
pinMode(dirY, OUTPUT);
pinMode(stepZ, OUTPUT);
pinMode(dirZ, OUTPUT);
pinMode(enPin, OUTPUT);
digitalWrite(enPin, LOW);
digitalWrite(dirX, HIGH);
digitalWrite(dirY, HIGH);
digitalWrite(dirZ, HIGH);
digitalWrite(dirA, HIGH);
}
void loop()
{
CommCheck(); //checks serial buffer for data commands
runMotors();
}
void runMotors()
{
if ((FLStepper.distanceToGo() != 0) || (FRStepper.distanceToGo() != 0) || (BLStepper.distanceToGo() != 0) || (BRStepper.distanceToGo() != 0))
{
FLStepper.run();
//BLStepper.run();
FRStepper.run();
//BRStepper.run();
movementComplete = true;
}
if (movementComplete == true)
{
CommConfirm();
movementComplete = false;
}
//if ((FLStepper.distanceToGo() == 0) && (FRStepper.distanceToGo() == 0) && (BLStepper.distanceToGo() == 0) && (BRStepper.distanceToGo() == 0))
//if ((FLStepper.distanceToGo() == 0) || (FRStepper.distanceToGo() == 0) || (BLStepper.distanceToGo() == 0) || (BRStepper.distanceToGo() == 0))
//{
//movementComplete = true;
//}
}
void CommCheck()
{
if(Serial.available()) //checks to see if there is serial data has been received
{
//int len = Serial.available(); //stores the character lengh of the command that was sent
//this is used for command parsing later on
String command = Serial.readString(); //stores the command as a text string
int len = command.length();
//Serial.println(command);
Serial.flush();
//command.remove(len-2,1); //removes characters added by the pi's serial data protocol
//command.remove(0,2);
//len -= 3; //updates the string length value for parsing routine
int points[2] = {0, 0}; //offset points for where we need to split the command into its individual parts
for(int x = 0; x < len; x++) //this loop will go through the entire command to find the split points based on
{ //what the split variable declared at the top of the script is set to.
//Serial.print("Char ");
//Serial.print(x);
//Serial.print("- ");
//Serial.println(command[x]);
if(command[x] == split) //this goes through every character in the string and compares it to the split character
{
if(points[0] == 0) //if the first split point hasn't been found, set it to the current spot
{
points[0] = x;
}
else //if the first spot was already found, then set the second split point
{ //this routine is currently only set up for a command syntax that is as follows
points[1] = x; //command:datavalue1:datavalue2
}
}
}
CommParse(command, len, points[0], points[1]); //now that we know the command, command length, and split points,
} //we can then send that information out to a routine to split the data
} //into individual values.
void CommParse(String command, int len, int point1, int point2)
{
//Serial.print("Command Length: ");
//Serial.println(len);
//Serial.print("Split 1: ");
//Serial.println(point1);
//Serial.print("Split 2: ");
//Serial.println(point2);
String com = command; //copy the full command into all 3 parts
String val1 = command; //this is needed for the string manipulation
String val2 = command; //that follow
com.remove(point1, len - point1); //each of these use the string remove to delete
val1.remove(point2, len - point2); //the parts of the command that aren't needed
val1.remove(0, point1 + 1); //basically splitting the command up into its
val2.remove(0, point2 + 1); //individual pieces
val2.remove(val2.length()-1,1);
CommLookup(com, val1, val2); //these pieces are then sent to a lookup routine for processing
}
void CommLookup(String com, String val1, String val2)
{
int offset = 255; //create a variable for our lookup table's offest value
//we set this to 255 because there won't be 255 total commands
//and a valid command can be offset 0, so it's just to avoid
//any possible coding conflicts if the command sent doesn't
//match anything.
for(int x = 0; x < listSize; x++) //this goes through the list of commands and compares
{ //them against the command received
if(commands[x] == com)
{
offset = x; //if the command matches one in the table, store that command's offset
}
}
switch(offset) //this code compares the offset value and triggers the appropriate command
{
case 0: //essentially a hello world. | Syntax: hello:null:null
CommHello(); //this activates the hello world subroutine | returns Hello!
break;
case 1: //adds both values together and return the sum. | Syntax: add:value1:value2
CommAdd(val1.toInt(), val2.toInt()); //this activates the addition subroutine | returns value1 + value2
break;
case 2: //subtracts both values and return the difference | Syntax: subtract:value1:value2
CommSub(val1.toInt(), val2.toInt()); //this activates the subtraction subroutine | returns value1 - value2
break;
case 3:
yMovement(val1.toInt(), val2.toInt());
break;
case 4:
xMovement(val1.toInt(), val2.toInt());
default: //this is the default case for the command lookup and will only
Serial.println("Command not recognized"); //trigger if the command sent was not known by the arduino
break;
}
}
void CommHello() //each of these routines are what will be triggered when they are successfully processed
{
Serial.println("Hello!");
CommConfirm();
}
void CommAdd(int val1, int val2)
{
Serial.println(val1 + val2);
CommConfirm();
}
void CommSub(int val1, int val2)
{
Serial.println(val1 - val2);
CommConfirm();
}
void yMovement(int val1, int val2)
{
if (val1 < 0) {
int yMoveNew = (val1 * (-4));
//Serial.println(val1 * (-1));
//delay(500);
FRStepper.moveTo(-yMoveNew);
BRStepper.moveTo(-yMoveNew);
FLStepper.moveTo(-yMoveNew);
BLStepper.moveTo(-yMoveNew);
//delayMicroseconds(500);
}
else {
int yMoveNew = (val1 * 4);
//Serial.println(val1);
//delay(500);
FRStepper.moveTo(yMoveNew);
BRStepper.moveTo(yMoveNew);
FLStepper.moveTo(yMoveNew);
BLStepper.moveTo(yMoveNew);
//delayMicroseconds(500);
}
}
void xMovement(int val1, int val2)
{
if (val1 < 0) {
int xMoveNew = (val1 * (-4));
//Serial.println(val1 * (-1));
//delay(1000);
FLStepper.moveTo(-xMoveNew);
BLStepper.moveTo(-xMoveNew);
FRStepper.moveTo(-xMoveNew);
BRStepper.moveTo(-xMoveNew);
//delayMicroseconds(500);
}
else {
int xMoveNew = (val1 * 4);
//Serial.println(val1);
//delay(1000);
FLStepper.moveTo(xMoveNew);
BLStepper.moveTo(xMoveNew);
FRStepper.moveTo(xMoveNew);
BRStepper.moveTo(xMoveNew);
//delayMicroseconds(500);
}
}
void CommConfirm()
{
Serial.println("Done");
}
