Issues while communicating to Arduino

Hello,
I recently built some actuators using stepper motors. The wiring is done and everything is fixed on the chassis. I'm now tackling the software part.
I'm using an Arduino R4 Minima. I plan to use Simtools or FlyPt. I've tested a lot of Arduino code (even Lebois' SRT100) that could work with my stepper, but nothing works, no motor moves. So I downloaded a test code that just moves the actuators up and down without any communication with Simtools or anything else, in a loop. It works perfectly. So there's no problem with the wiring or the motors. I tried the previous codes by testing them on the Serial Monitor. And there, I get nothing. I tested this with eaorobbie's code and this "remix":

Code:

//********************************************************************************************
// Simtools Stepper 1 Axis code
// Based on code By EAOROBBIE (Robert Lindsay)
// By Peter Brennan

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

#include <AccelStepper.h>

#define DEBUG 1                                    // comment out this line to remove debuggin Serial.print lines

// Define a stepper and the pins it will use
AccelStepper stepper(AccelStepper::DRIVER, 2, 3);

const char kEOL = '~';                              // End of Line - the delimiter for our acutator values
const int kMaxCharCount = 3;                        // some insurance...
int valueCharCount = 0;                             // how many value characters have we read (must be less than kMaxCharCount!!
int actuatorPosition = 0;                           // current Actuator position, initialised to 0
int newActuatorPosition = 0;                        // initialise variable to collect new motor position

// set up some states for our state machine
// psReadActuator = 0
// psReadValue = 1
int currentState = 0;

void setup()
{
  // Set base values for stepper speed and acceleration as well as setting current pos to 0
  stepper.setMaxSpeed(2000);
  stepper.setAcceleration(1000);
  stepper.moveTo(0);

   Serial.begin(9600); // opens serial port at a baud rate of 9600
}



// this code only runs when we have serial data available. ie (Serial.available() > 0).
void serialEvent() {
    char tmpChar;
    int tmpValue;

    while (Serial.available()) {
        // if we're waiting for a Actuator name, grab it here
       if (currentState == 0) {
            tmpChar = Serial.read();

#ifdef DEBUG
Serial.print("read in ");           
Serial.println(tmpChar);
#endif

if (tmpChar == 'P') {

#ifdef DEBUG
Serial.print("which is actuator ");           
Serial.println('P');
#endif

currentState = 1;                 // start looking for the Actuator position
valueCharCount = 0;                         // initialise number of value chars read in
                    break;
}
       }
 

// if we're ready to read in the current Actuator's position data
        if (currentState == 1) {       
        
            while ((valueCharCount < kMaxCharCount) && Serial.available()) {
            
                tmpValue = Serial.read();
              
                if (tmpValue != kEOL) {
                
                    tmpValue = tmpValue - 48;
      
                    if ((tmpValue < 0) || (tmpValue > 9)) tmpValue = 0;
                    // Determine the new position for the stepper
                    newActuatorPosition = newActuatorPosition * 10 + tmpValue;
                    valueCharCount++;
                }
                else break;
            }
          
            // if we've read the value delimiter, update the Actuator and start looking for the next Actuator name
            if (tmpValue == kEOL || valueCharCount == kMaxCharCount) {
#ifdef DEBUG           
Serial.print("Move to ");           
Serial.println(newActuatorPosition);
#endif
// Transfer the new actuator value to the current one, and reset the new position
          actuatorPosition = newActuatorPosition;
          currentState = 0;
          newActuatorPosition = 0;
            }
        } }
    }
  
    void loop()
{
// Move the stepper to the desired position if nto already there
     stepper.moveTo(actuatorPosition);
stepper.run();
}

Any help could be precious.
Thank you,
Tintin Boulsard

I also found this one but when I send for example "R170~" in the Serial Monitor, I don't receive anything in return and the stepper motor does not move.
So I think the problem is not coming from the code but from the Arduino or the communication with it. My Arduino R4 Minima is new, I just ordered it a few days ago. I had the same problem with an Arduino R3 before ordering the R4 but it was an unofficial Arduino, so that is matbe why it could not work before.

I hope someone could help me,
Thanks,
Tintin Boulsard

Code:

//
#define DEBUG 1                                    // comment out this line to remove debuggin Serial.print lines

// Declare pins
int STEP[] = {31,33,35,37,39,41};    // Step Pins,  active HIGH
int DIR[] = {30,32,34,36,38,40};     // Direction Pins, active HIGH
byte DIR_ACTIVE[] = {LOW, LOW, LOW, LOW, LOW, LOW};

const int kAxisCount = 6;                          // how many axis we are handling

int Pos[] = {0,0,0,0,0,0}; //Position logging

const char kAxisName[kAxisCount] = {'R','P','H','Y','S','U'};    // the letters ("names") sent from Sim Tools to identify each axis
const int kAxisScale[kAxisCount][6] = { {0,999},{0,999},{0,999},{0,999},{0,999},{0,999} };  //Scaling
const char kEOL = '~';                             // End of Line - the delimiter for our acutator values
const int kMaxCharCount = 3;                       // some insurance to 8 bit...
int axisPosition[kAxisCount] = {0,0,0,0,0,0};         // current Axis positions, initialised to 127 middle for 8 bit
int currentAxis;                                   // keep track of the current Axis being read in from serial port
int valueCharCount = 0;                            // how many value characters have we read (must be less than kMaxCharCount!!

// set up some states for our state machine
// psReadAxis = next character from serial port tells us the Axis info that follows
// psReadValue = next characters from serial port until we hit our kMaxCharCount or kEOL which tells us the value
enum TPortState { psReadAxis, psReadValue };
TPortState currentState = psReadAxis;

void setup()  {
  Serial.begin(921600);
 
  // Define pins
  for (int i=0; i < kAxisCount; i++)  {
    pinMode(STEP[i], OUTPUT);
    pinMode(DIR[i], OUTPUT);
  }
}

void loop()
{
for (int i = 0; i < kAxisCount; i++) {
// check new position
if (Pos[i] != axisPosition[i])  {
 
  // check direction and write DIR pin
  if (Pos[i] >= axisPosition[i])  {
  digitalWrite(DIR[i], LOW);
  Pos[i] = Pos[i] - 1;
    }
 
  if (Pos[i] < axisPosition[i])  {
  digitalWrite(DIR[i], HIGH);
  Pos[i] = Pos[i] + 1;
    }
 
    // make one step
    digitalWrite(STEP[i], HIGH);
    delayMicroseconds(500);
    digitalWrite(STEP[i], LOW);
    delayMicroseconds(500);
 
    //break;
}}}

// this code only runs when we have serial data available. ie (Serial.available() > 0).
void serialEvent() {
    char tmpChar;
    int tmpValue;

    while (Serial.available()) {
        // if we're waiting for a Axis name, grab it here
        if (currentState == psReadAxis) {
            tmpChar = Serial.read();
         
#ifdef DEBUG          
Serial.print("read in ");          
Serial.println(tmpChar);          
#endif
        for (int i = 0; i < kAxisCount; i++) {    // look for our axis in the array of axis names we set up
        if (tmpChar == kAxisName[i]) {
#ifdef DEBUG          
Serial.print("which is axis ");          
Serial.println(i);          
#endif
                    currentAxis = i;                            // remember which axis we found
                    currentState = psReadValue;                 // start looking for the Axis position
                    axisPosition[currentAxis] = 0;              // initialise the new position
                    valueCharCount = 0;                         // initialise number of value chars read in
                    //break;
                }
            }
        }
     
        // if we're ready to read in the current Axis position data
        if (currentState == psReadValue) {
            while ((valueCharCount < kMaxCharCount) && Serial.available()) {
                tmpValue = Serial.read();
                if (tmpValue != kEOL) {
                    tmpValue = tmpValue - 48;
                    if ((tmpValue < 0) || (tmpValue > 9)) tmpValue = 0;
                    axisPosition[currentAxis] = axisPosition[currentAxis] * 10 + tmpValue;
                    valueCharCount++;
                }
                else break;
            }
         
            // if we've read the value delimiter, update the Axis and start looking for the next Axis name
            if (tmpValue == kEOL || valueCharCount == kMaxCharCount) {
           
           
              // scale the new position so the value is between 0 and 179
              axisPosition[currentAxis] = map(axisPosition[currentAxis], 0, 255, kAxisScale[currentAxis][0], kAxisScale[currentAxis][1]);
              // updateAxis(currentAxis);
           
#ifdef DEBUG          
Serial.print("read in ");          
Serial.println(axisPosition[currentAxis]);
Serial.print("Position ");          
Serial.println(Pos[currentAxis]);
#endif
             
                currentState = psReadAxis;
            }
        }
    }
}

i also into steppenmotor setup . arduino setup ,nema 34 with 12 nm . arduno uno , got 2 of them here r3 . a red one and a bleu one . did do a blink test with them and figure out that the blue did not recieve code ..not blinking no writing onto it , broke ? , the red one did blink and accept writing..what arduino are you using ? red , blue , black ? i.m in the proces to wire things up , but do steppenmotors not need a ..home ..position ? with switch ? i got steppenmotors with no encoders . looking to ad home switch onto it . will this weekend wire them up and using the code above . with my other wp motors motion rig i did get the same problem , orderd a new uno r3 elegoo black . for going from 2 dof to 4 dof , blinking test onto my home pc did work . game pc wil not see the new uno ? 2 uno setup is with direct usb input to the game pc , not with a hub ..game pc is with new install windows 11 , maybe i,m missing some drivers ? i did wanted to open a new topic for steppenmotors , but i did see this topic , so i,m jumping into this one .. seem to be that whe are in the same direction and procedure ..and problems

Hi harrie,
Welcome to this topic... I can see that we are working on a same project. So that's nice, maybe will we work together and help each other....
For info, I use 4 stepper motors with encoder of 8,5Nm. I first decided to buy them in open loop and 12Nm but I read on Internet that closed loop were more precise, and also there was much more infos were I bought them.
I'm using an official Arduino R4 Minima, so it is not totally blue but between the green and the blue. Often, the red, blue and black Arduino s are not official.
Personally, I don't use any home position switches, I'm going to calibrate them my self on the software, such as Simtools or FlyPt Mover.
Normally, you should be able to connect the Arduino to your gaming PC without any problem. You don't need any driver, except the Arduino IDE software.
I'll do more tests with Arduino and the steppers, and I'll send you the results. Maybe it will help you if I arrive to make it work.

Tintin Boulsard

hi @Tintin Boulsard.

i,m using the nema 34 without encoder , because i did update my cnc machine with servos . so left over 4 x nema 34 . wil gone wiring up 1 nema this weekend and test it with above sketch : this sketch is for mega 2560 when i see pin connections ?


// Declare pins
int STEP[] = {31,33,35,37,39,41}; // Step Pins, active HIGH
int DIR[] = {30,32,34,36,38,40}; // Direction Pins, active HIGH
byte DIR_ACTIVE[] = {LOW, LOW, LOW, LOW, LOW, LOW};

and nice to share for to setting this up . when wired up i give it a test and writhe the result in here . i did printed the actuator parts in 10% alu filament , verry rare and absoluut strong filament . printing with 170 C , the setup is with 1605 trapezium tread and pom-c ballnuts . got the tool for making these ballnuts . did orderd the alu profiles 300mm lengte , amazone, its all a cheap setup for parts , but i wanted to give it a try because the leftover nema,s .. did read alot onto this forum , but not much for steppenmotors . my first sim motion rig is working for now with 2 dof , this steppenmotor setup wil go into the ferrari p4/5 project .

Hi @harrie,
The code above is made for the Arduino Mega, as you said, but you can easily modify it for your 4 motors and your Arduino Uno :

Code:

// Declare pins
int STEP[] = {2,4,6,8};    // Step Pins,  active HIGH
int DIR[] = {3,5,7,9};     // Direction Pins, active HIGH
byte DIR_ACTIVE[] = {LOW, LOW, LOW, LOW};

const int kAxisCount = 4;                          // how many axis we are handling

int Pos[] = {0,0,0,0}; //Position logging

const char kAxisName[kAxisCount] = {'R','P','H','Y'};    // the letters ("names") sent from Sim Tools to identify each axis
const int kAxisScale[kAxisCount][6] = { {0,999},{0,999},{0,999},{0,999} };  //Scaling
const char kEOL = '~';                             // End of Line - the delimiter for our acutator values
const int kMaxCharCount = 3;                       // some insurance to 8 bit...
int axisPosition[kAxisCount] = {0,0,0,0};         // current Axis positions, initialised to 127 middle for 8 bit
int currentAxis;                                   // keep track of the current Axis being read in from serial port
int valueCharCount = 0;                            // how many value characters have we read (must be less than kMaxCharCount!!

It looks like you 3D printed the slider used for the OpenSFX100 but these use a 100x100 aluminium profile. And as I can see, you ordered 80x80 profiles, so it will not work. Am I wrong ?

Tintin Boulsard

And here is the wiring I use, if it can help you...

you are wright , sfx-100 slider . the slider was my first print from a stl site sfx-100 . based onto the nema 80x80 dimension i design the actuator 80x80x300., did have an arduino mega and already downloaded the sketch onto it . after a error type error my motion seat 1 is broke , gone fix this tomorrow , and get back to wiring up the nema setup .. we wil see if it wil work with this sketch , i wil posting here when i got them wired up and testrun

I tested multiple codes.
None of the Arduino codes above work, so I'm writing my own code and testing it step by step. It is for the moment working perfectly. I have to add a few others lines to make it totally work with Simtools, and I'll share it with you..

Tintin Boulsard

Hi @harrie !
Did you wired yours actuators? And tested them?

I just finished the code, which is working almost perfectly! You can run it using Simtools, or in DEBUG mode in the Serial Monitor but you have to uncomment the "//define DEBUG 1" line. Actually, I'm using a code made by @eaorobbie that I then modified to make it work properly on stepper motors.
If you want to use it, you must install the StepperDriver library and modify the pins in the code, depending on you wiring.
The datas sent are in this format : "Rxxx~" where xxx is a value between 0 and 255. Also, there is a scaling value that corresponds in this code to the range (look at picture below). I don't know if this value is in steps or microsteps, or other but I recommend you to test, and adjusting to the range of your actuator, by increasing a little bit at each time. Attention, leave the negative sign : { -10000, 10000 }.
You can modify the speed of the stepper : #define RPM 400.
It is for the moment for only one axis, but I'm going to modify it for 4 axis soon.
And lastly, the only issue I have is that when I "Output Test" the code and steppers with Simtools, I have to slide the cursor slowly, otherwise, it goes in multiple directions fastly, and after a few seconds it stops and works well again. I have to fix that, but I'm using Simtools in Demo, so maybe it is not coming from my code, so I'll buy a licence.

Tintin Boulsard

Code:

#include <BasicStepperDriver.h>

//------------------------- Can be modified --------------------------//
#define STEP 3
#define DIR 4
#define RPM 400
#define MICROSTEPS 16
#define MOTOR_STEPS 200
//define DEBUG 1
//--------------------------------------------------------------------//

BasicStepperDriver stepper(MOTOR_STEPS, DIR, STEP);

const int kActuatorCount = 1;  //Number of actuators
const char kActuatorName[kActuatorCount] = {'R'};
const int kActuatorScale[kActuatorCount][2] = { { -10000, 10000 } }; //Scaling, where 1000 is the range
const char kEOL = '~';
const int kMaxCharCount = 3;
int actuatorPosition[kActuatorCount] = {0};
int actuatorPosition2[kActuatorCount] = {0};
int currentActuator;
int valueCharCount = 0;
int remember[kActuatorCount] = {0};
enum TPortState { psReadActuator, psReadValue }; 
TPortState currentState = psReadActuator;

void setup(){
  Serial.begin(9600);
  stepper.begin(RPM, MICROSTEPS);
  }

void loop()
{
}

void serialEvent(){
    char tmpChar;
    int tmpValue;

    while (Serial.available()) {
        if (currentState == psReadActuator) {
            tmpChar = Serial.read();
  
#ifdef DEBUG           
Serial.print("read in ");           
Serial.println(tmpChar);           
#endif

            for (int i = 0; i < kActuatorCount; i++) {
                if (tmpChar == kActuatorName[i]) {

#ifdef DEBUG           
Serial.print("which is actuator ");           
Serial.println(i);           
#endif

                    currentActuator = i;
                    currentState = psReadValue;             
                    actuatorPosition[currentActuator] = 0; 
                    valueCharCount = 0;         
                    break;
                }
            }
        }
      
        if (currentState == psReadValue) {
            while ((valueCharCount < kMaxCharCount) && Serial.available()) {
                tmpValue = Serial.read();
                if (tmpValue != kEOL) {
                    tmpValue = tmpValue - 48;
                    if ((tmpValue < 0) || (tmpValue > 9)) tmpValue = 0;
                    actuatorPosition[currentActuator] = actuatorPosition[currentActuator] * 10 + tmpValue;
                    valueCharCount++;
                }
                else break;
            }
          
            if (tmpValue == kEOL || valueCharCount == kMaxCharCount) {

#ifdef DEBUG           
Serial.print("read in ");           
Serial.println(actuatorPosition[currentActuator]);           
#endif


                actuatorPosition[currentActuator] = map(actuatorPosition[currentActuator], 0, 255, kActuatorScale[currentActuator][0], kActuatorScale[currentActuator][1]);
#ifdef DEBUG           
Serial.print("scaled to ");           
Serial.println(actuatorPosition[currentActuator]);   
#endif

actuatorPosition2[currentActuator] = actuatorPosition[currentActuator] - remember[currentActuator];
remember[currentActuator] = actuatorPosition[currentActuator];   //Remember actuator position
                updateActuator(currentActuator);
                currentState = psReadActuator;
            }
        }
    }

    
}


void updateActuator(int thisActuator) {
    stepper.move(actuatorPosition2[thisActuator]); 
}

Range Image

SimTools Settings

Hi @harrie,
Have a look to this post, maybe it can help you : LINK.

Best regards,
Tintin Boulsard

just did cnc make some parts for the broken rig , got the actuator parts almost ready now and will assemble it and test run when wiring up the whole thing ...stil bizzy with assembeling the new/broken motion box .

what i understand is that the demo simtool works like the licens , with lfs for a demo game . did workt here onto the other rig i got .licens is only for that you can ad more plugins? correct me if i,m wrong .. and yes , always start low in settings and dont make a typing error ...... like i did .. thats why the other rig motionbox did broke . realy did lift me out of the seat

Hello @harrie,
Be careful with your "motion box" ! The goal of motion simulators is not to hurt you...
Your rig looks awesome! Did you make it yourself?
Yes, you can download Simtools plugins from the "Downloads" section of XSimulator website, or buy a licence so you can download as much plugins as you want, in addition to the Simtools software licence.
Which Arduino code are you going to use? The one a modified myself, one of the codes at the top of this topic, or even an other one?
For the home position switch, I see that you absolutely want to use them, so you can easily add some lines to the code. I recommend you to use the code I modified because I added a variable that "remember" the position of the actuators, so it calculate the distance to go, either it will turn again and again, thinking at each loop that the actuator is at the home position. I do my best to explain you that in English, so sorry if I'm not clear enough. Then you can add some precision in the position of the actuator, by using your home switches and adding in the loop something like "if the Arduino receive a signal from the switch, it set my "remember" variable to '0' (127 coming out of Simtools then scaled to 0 for the StepperDriver library).

I hope you can understand me,
Best regards,
Tintin Boulsard

the rig nr 1 , home made prototype . al plans in autocad , free to share . al made on my home cnc . verry nice fitting/assembeling , cheap wooden parts . the body position is perfect .... al evening dirtrally , no problem with not good sitting , pain ore something .. it is a prototype and already making it in alu and carbon parts . al wil be finish in alcantare like the seat . complete rig in alcantara ...the side arms that go up for getting into the seat is electrik . also foot pedals are electric forward ore backwards .
good idee for me is to wait with the software , i,m seeing you are better with arduino writing then me.. this setup is for rig nr 2 ferrari , i,m not in a hurry with it . got it al layout now , nema motor , driver , power , wiring to arduino mega2560 . but no software onto the mega yet ...
motion box almost ready again , for a new testdrive again ....and now with 3 dof and yaw motion .

I tried this code in V3, but doesn't work for me. The stepper just starts turning randomly when I click test in interface settings. What should the microstepping dip switches be set to on the stepper?

Hi @early_m,
I'm sorry that the code doesn't work for you.
Try to replace the line "//define DEBUG" by "#define DEBUG". Check that Simtools is totally closed. Then open the Serial Monitor from Arduino IDE, select 9600 baud rate, and try to send "R127~". Normally, it should not move, or only of one or two steps. Then send "R255~" and it should turn a lot in a direction, and if you send R127~ again, it should turn in the opposite direction, to get back at the first position.
If it works, your issue maybe comes from the communication with Simtools... Which version of Simtools are you using?
And please, can you send me what stepper are you using, and the name of the driver, so I can send you back the driver switches configuration.

Best regards,
Tintin Boulsard

Edit : If it works in the Serial Monitor, compare the Simtools configuration with the one I published there. If it still doesn't work, try to change the Output Type to Binary, Hex, or Decimal....and remove all your axis assignments, and in Output Test, select, instead of DOF axis, the second option where you can find Axis1a...

I tried serial monitor, it works fine. I close down Arduino IDE and test in simtools - no joy.

I am using simtools V3 with the interface settings in your post. I've tried binary/hex/decimal - still does not work.

My stepper is this one https://www.aliexpress.com/item/100....order_list.order_list_main.15.6e601802T6MHSm it has a built in driver

Thanks for your help

As it works well in the Serial Monitor, it seems that the problem is coming from the communication between Simtools and the Arduino.
You should try installing Simtools v2, the v3 is still in Beta, so maybe it will work better using Simtools v2...
Which Arduino do you use? I had an unofficial Arduino Uno R3, that I had bought on AliExpress, but thinking it would be more reliable, I bought an official Uno R4 Minima. I then tested my code on the R4, using the Serial Monitor and it was working well. But, on Simtools, there was no any response. No any motor moved. So I tested with my "fake" Uno R3, and it worked perfectly on Simtools. As a conclusion, my fake Uno R3 works better than my official Uno R4 Minima.
So maybe using a different Arduino will work?
And for the switches configuration, you normally have a sticker on the stepper where you have all the configurations. I use the "3200" one, but it is not our problem, as it is working in the Serial Monitor...

Best regards,
Tintin Boulsard