Help using serial data to control a stepper motor

Projects Programming
1

This will be my first ever submission to the forum as I am royally stumped, I had made a functional version of the code that had first used the parseFloat and that had the unintended effect of halting the code per line of serial update. I successfully can interpret the serial data again this time using the serial input basics examples to parse my data, unfortunately with liveWeightFunc unsuppressed I stop receiving serial data and if I modify the while statement the stepper motor runs without stopping. I'm confused because I can print the variable but as soon as I try to compare liveWeight to targetWeight the code breaks. My understanding of the void loops vs external type functions are limited. Any help would be greatly appreciated.

#include <TMCStepper.h>
//#include <AccelStepper.h>

#define EN_PIN           5 // Enable
#define DIR_PIN          2 // Direction
#define STEP_PIN         3 // Step
#define SW_SCK           4 // Software Slave Clock (SCK)

#define SERIAL_PORT Serial1 // TMC2208/TMC2224 HardwareSerial port
#define DRIVER_ADDRESS 0b00 // TMC2209 Driver address according to MS1 and MS2
#define R_SENSE 0.11f //SilentStepStick series use 0.11

TMC2209Stepper driver(&SERIAL_PORT, R_SENSE, DRIVER_ADDRESS); // Hardware Serial
//AccelStepper stepperA = AccelStepper(stepperA.DRIVER, STEP_PIN, DIR_PIN);

constexpr uint32_t steps_per_round = 200*16;

const byte numChars = 32;
char receivedChars[numChars];
char tempChars[numChars];        // temporary array for use when parsing

      // variables to hold the parsed data
char messageFromPC[numChars] = {0};
int integerFromPC = 0;
float liveWeight = 0;      //Live Weight

boolean newData = false;

float targetWeight = 0.5; //Target
int steps = 0;            // Steps to Target


void setup() {
  Serial.begin(9600);   // Serial Monitor
  Serial2.begin(9600, SERIAL_8N1, 8, 9);  // RS232    8RX 9TX ON THE CONVERTER
  delay(50);

  pinMode(EN_PIN, OUTPUT);
  pinMode(STEP_PIN, OUTPUT);
  pinMode(DIR_PIN, OUTPUT);
  digitalWrite(EN_PIN, HIGH);      

  SERIAL_PORT.begin(115200);      // HW UART drivers
  driver.begin();                 //  SPI: Init CS pins and possible SW SPI pins
  driver.toff(5);                 // Enables driver in software
  driver.rms_current(200);        // Set motor RMS current
  driver.microsteps(16);          // Set microsteps to 1/8th

//driver.en_pwm_mode(true);       // Toggle stealthChop on TMC2130/2160/5130/5160
  driver.en_spreadCycle(true);   // Toggle spreadCycle on TMC2208/2209/2224
  driver.pwm_autoscale(true);     // Needed for stealthChop

//  stepperA.setMaxSpeed(steps_per_round*20); // 100mm/s @ 80 steps/mm
//  stepperA.setAcceleration(5000); // 2000mm/s^2
//  stepperA.setEnablePin(EN_PIN);
//  stepperA.setPinsInverted(false, false, true);
//  stepperA.enableOutputs();
//  stepperA.setCurrentPosition(0);

}

bool shaft = false;

void loop() {
  recvWithStartEndMarkers();  // Serial Input format is "   0.000g"
    if (newData == true) {
        strcpy(tempChars, receivedChars);
          // this temporary copy is necessary to protect the original data
          //   because strtok() used in parseData() replaces the commas with \0
        parseData();
        showParsedData();
        newData = false;
        
    }


  //targetWeightFunc();


  //if(targetWeight, 3 > liveWeight, 3){
  //  digitalWrite(EN_PIN, LOW);
  //  while (1) {

  //    digitalWrite(DIR_PIN, HIGH);
  //    digitalWrite(STEP_PIN, LOW);
  //    delayMicroseconds(100);
  //    digitalWrite(STEP_PIN, HIGH);
  //    delayMicroseconds(100);

  //  }
  //}
  //else{
  //  digitalWrite(EN_PIN, HIGH);
  //}

  //shaft = !shaft;
  //driver.shaft(shaft);
}

//============

void recvWithStartEndMarkers() {
    static boolean recvInProgress = false;
    static byte ndx = 0;
    char startMarker = '   ';
    char endMarker = 'g';
    char rc;

    while (Serial2.available() > 0 && newData == false) {
        rc = Serial2.read();

        if (recvInProgress == true) {
            if (rc != endMarker) {
                receivedChars[ndx] = rc;
                ndx++;
                if (ndx >= numChars) {
                    ndx = numChars - 1;
                }
            }
            else {
                receivedChars[ndx] = '\n'; // terminate the string
                recvInProgress = false;
                ndx = 0;
                newData = true;
            }
        }

        else if (rc == startMarker) {
            recvInProgress = true;
        }
    }
}

//============

void parseData() {      // split the data into its parts

    char * strtokIndx; // this is used by strtok() as an index
    strtokIndx = strtok(tempChars, "g");
    liveWeight = atof(strtokIndx);     // convert this part to a float

}

//============

void showParsedData() {
  Serial.println(liveWeight, 3);
}

//void targetWeightFunc() {
//  if(liveWeight, 3 < targetWeight, 3){
//    digitalWrite(EN_PIN, LOW);
//    while (1) {

//      digitalWrite(DIR_PIN, HIGH);
//      digitalWrite(STEP_PIN, LOW);
//      delayMicroseconds(100);
//      digitalWrite(STEP_PIN, HIGH);
//      delayMicroseconds(100);

//    }
//  }
//  else{
//    digitalWrite(EN_PIN, HIGH);
//  }

//  shaft = !shaft;
//  driver.shaft(shaft);

//}
2

Welcome and thanks for using code tags in your first post.

There is no liveWeightFunc in your code.

What kind of construction is that? What do you think that it achieves?

Below demonstrates what happens when using the comma operator

void setup()
{
  float a = 3;
  float b = 5;
  float c;

  Serial.begin(115200);
  c = a, b;
  Serial.println(c);
  c = (a, b);
  Serial.println(c);
}

void loop()
{
}

I guess you do not want to use the comma operator in those if statements.

3

I apologize for taking your time I should have just stuck with it a little longer. I had commented out the code to the point where it worked again but if I had included those portions I was getting nothing. I have it currently working I couldn't say where the problem lied. Off to find another.....

I was hoping that limiting the floating size would make the function work, thinking it was a limitation of the esp32 chip. I corrected it to elminate the ", 3".