Plot stallGuard value

stallGuard_arduino

```cpp
/*
  Trinamic TMC2130 Example
*/

#include <SPI.h>

// Note: You also have to connect GND, 5V and VM.
//       A connection diagram can be found in the schematics.
#define EN_PIN    38  // Nano v3:  16 Mega:  38  //enable (CFG6)
#define DIR_PIN   55  //           19        55  //direction
#define STEP_PIN  54  //           18        54  //step

#define CS_PIN    40  //           17        64  //chip select
#define MOSI_PIN MOSI //51 //SDI/MOSI (ICSP: 4, Uno: 11, Mega: 51)
#define MISO_PIN MISO //50 //SDO/MISO (ICSP: 1, Uno: 12, Mega: 50)
#define SCK_PIN  SCK //52 //CLK/SCK  (ICSP: 3, Uno: 13, Mega: 52)

//TMC2130 registers
#define _WRITE          0x80 //write flag
#define REG_GCONF      0x00
#define REG_GSTAT      0x01
#define REG_IHOLD_IRUN 0x10
#define REG_CHOPCONF   0x6C
#define REG_COOLCONF   0x6D
#define REG_DCCTRL     0x6E
#define REG_DRVSTATUS  0x6F
#define REG_TCOOLTHRS  0x14
#define REG_TPWMTHRS   0x13
#define REG_TSTEP      0x12

#define NUMBER_OF_STEPS 14000
int stepCount = 0;

#include <TMC2130Stepper.h>
TMC2130Stepper TMC2130 = TMC2130Stepper(EN_PIN, DIR_PIN, STEP_PIN, CS_PIN);

uint8_t tmc_write(uint8_t cmd, uint32_t data)
{
  uint8_t s;

  digitalWrite(CS_PIN, LOW);

  s = SPI.transfer(cmd);
  SPI.transfer((data>>24UL)&0xFF)&0xFF;
  SPI.transfer((data>>16UL)&0xFF)&0xFF;
  SPI.transfer((data>> 8UL)&0xFF)&0xFF;
  SPI.transfer((data>> 0UL)&0xFF)&0xFF;

  digitalWrite(CS_PIN, HIGH);

  return s;
}

uint8_t tmc_read(uint8_t cmd, uint32_t *data)
{
  uint8_t s;

  tmc_write(cmd, 0UL); //set read address

  digitalWrite(CS_PIN, LOW);

  s = SPI.transfer(cmd);
  *data  = SPI.transfer(0x00)&0xFF;
  *data <<=8;
  *data |= SPI.transfer(0x00)&0xFF;
  *data <<=8;
  *data |= SPI.transfer(0x00)&0xFF;
  *data <<=8;
  *data |= SPI.transfer(0x00)&0xFF;

  digitalWrite(CS_PIN, HIGH);

  return s;
}

void setup()
{
  delay(1500);
  pinMode(12, OUTPUT);
  digitalWrite(12, HIGH);
  delay(500);

  cli();//stop interrupts
  //set timer1 interrupt at 1Hz
  TCCR1A = 0;// set entire TCCR1A register to 0
  TCCR1B = 0;// same for TCCR1B
  TCNT1  = 0;//initialize counter value to 0
  // set compare match register for 1hz increments
  OCR1A = 256;// = (16*10^6) / (1*1024) - 1 (must be <65536)
  // turn on CTC mode
  TCCR1B |= (1 << WGM12);
  // Set CS12 and CS10 bits for 1024 prescaler
  TCCR1B |= (1 << CS11);// | (1 << CS10);  
  // enable timer compare interrupt
  TIMSK1 |= (1 << OCIE1A);
  sei();//allow interrupts

  //set pins
  pinMode(EN_PIN, OUTPUT);
  pinMode(DIR_PIN, OUTPUT);
  pinMode(STEP_PIN, OUTPUT);
  digitalWrite(EN_PIN, HIGH); //deactivate driver (LOW active)
  digitalWrite(DIR_PIN, LOW); //LOW or HIGH
  digitalWrite(STEP_PIN, LOW);

  pinMode(CS_PIN, OUTPUT);
  pinMode(MOSI_PIN, OUTPUT);
  pinMode(MISO_PIN, INPUT);
  pinMode(SCK_PIN, OUTPUT);
  digitalWrite(CS_PIN, HIGH);
  digitalWrite(MOSI_PIN, LOW);
  digitalWrite(MISO_PIN, HIGH);
  digitalWrite(SCK_PIN, LOW);

  //init serial port
  Serial.begin(250000); //init serial port and set baudrate
  while(!Serial); //wait for serial port to connect (needed for Leonardo only)
  Serial.println("\nStart...");

  //init SPI
  SPI.setDataMode(SPI_MODE3);
  SPI.setBitOrder(MSBFIRST);
  SPI.setClockDivider(SPI_CLOCK_DIV128);
  SPI.begin();

  //set TMC2130 config
  tmc_write(_WRITE|REG_IHOLD_IRUN, 0x10UL<<0 | 0x10UL<<8); //IHOLD=0x10, IRUN=0x10
  tmc_write(_WRITE|REG_CHOPCONF,   0x4UL<<24 | 0x1UL<<15 | 0x8UL<<0); //16 microsteps, MRES=0, TBL=1=24, TOFF=8
  TMC2130.coolstep_min_speed(1048575);
	TMC2130.diag1_stall(1);
	TMC2130.diag1_active_high(1);
	TMC2130.sg_stall_value(15);
	TMC2130.sg_filter(1);
  digitalWrite(EN_PIN, LOW);
}

ISR(TIMER1_COMPA_vect){
  digitalWrite(STEP_PIN, !analogRead(STEP_PIN));
  if (++stepCount >= NUMBER_OF_STEPS) {
  	//digitalWrite(DIR_PIN, !analogRead(DIR_PIN)); // Change direction
  	stepCount = 0;
  }
}

void loop()
{
  static uint32_t last_time=0;
  uint32_t ms = millis();
  uint32_t data;
  uint8_t s;
    
  if((ms-last_time) > 100) //run every 1s
  {
    last_time = ms;
    s = tmc_read(REG_DRVSTATUS, &data);
    Serial.println(data & 0x3FF, DEC);
  }
}
```