Spikes in PS2 joystick readings

Autonomous Robot, Manual Robot, DC Motor Driver, Stepper Motor Driver, Servo, Multi PWM chip.....

Spikes in PS2 joystick readings

Postby alantch » Tue Jun 08, 2021 1:48 pm

I just received a wireless PS2 controller from Cytron and have begun to run some tests on it with the SHIELD-MDD10 driving 2 motors and the PS2X library. What I found was that even with no input to the joysticks, the readings in the serial monitor will spike to maximum occasionally. This causes the motors to jerk when it happens. Below is the code I am using for the test.

CODE: SELECT_ALL_CODE
#include <PS2X_lib.h>           // library for PS2 controller
#include "CytronMotorDriver.h"  // library for Cytron SHIELD-MDD10 driver

/******************************************************************
 * set pins connected to PS2 controller:
 ******************************************************************/
#define PS2_DAT        13 
#define PS2_CMD        12
#define PS2_SEL        11
#define PS2_CLK        10

/******************************************************************
 * select modes of PS2 controller:
 *   - pressures = analog reading of push-butttons
 *   - rumble    = motor rumbling
 * uncomment 1 of the lines for each mode selection
 ******************************************************************/
#define pressures   false
#define rumble      false

PS2X ps2x; // create PS2 Controller Class
//right now, the library does NOT support hot pluggable controllers, meaning
//you must always either restart your Arduino after you connect the controller,
//or call config_gamepad(pins) again after connecting the controller.

CytronMD motor1(PWM_DIR, 3, 2);  // PWM 1 = Pin 3, DIR 1 = Pin 2
CytronMD motor2(PWM_DIR, 6, 7);  // PWM 2 = Pin 6, DIR 2 = Pin 7

int error = 0;
byte type = 0;
byte vibrate = 0;

void setup(){
 
  Serial.begin(57600);
 
  delay(300);  //added delay to give wireless ps2 module some time to startup, before configuring it
   
  error = ps2x.config_gamepad(PS2_CLK, PS2_CMD, PS2_SEL, PS2_DAT, pressures, rumble);
 
  if(error == 0){
    Serial.print("Found Controller, configured successful ");
    Serial.println("Try out all the buttons, X will vibrate the controller, faster as you press harder;");
    Serial.println("holding L1 or R1 will print out the analog stick values.");
    Serial.println("Note: Go to www.billporter.info for updates and to report bugs.");
  } 
  else if(error == 1)
    Serial.println("No controller found, check wiring, see readme.txt to enable debug. visit www.billporter.info for troubleshooting tips");
   
  else if(error == 2)
    Serial.println("Controller found but not accepting commands. see readme.txt to enable debug. Visit www.billporter.info for troubleshooting tips");

  else if(error == 3)
    Serial.println("Controller refusing to enter Pressures mode, may not support it. ");
 
  type = ps2x.readType();
  switch(type) {
    case 0:
      Serial.print("Unknown Controller type found ");
      break;
    case 1:
      Serial.print("DualShock Controller found ");
      break;
    case 2:
      Serial.print("GuitarHero Controller found ");
      break;
   case 3:
      Serial.print("Wireless Sony DualShock Controller found ");
      break;
   }
}

void loop() {
  if(error == 1) //skip loop if no controller found
    return;
 
    ps2x.read_gamepad(false, vibrate); // disable vibration of the controller

    int nJoyL = ps2x.Analog(PSS_LY); // read left stick; 0 - 255 value
    int nJoyR = ps2x.Analog(PSS_RY); // read right stick
   
    // nJoyL = map(nJoyL, 0, 255, 255, -255);  // 0 = stop; 255 = full forward; -255 = full reverse
    // nJoyR = map(nJoyR, 0, 255, 255, -255);

    Serial.print("L : "); Serial.print(nJoyL);
    Serial.print("     R : "); Serial.println(nJoyR);

    motor1.setSpeed(nJoyR);   // Motor 1
    motor2.setSpeed(nJoyL);   // Motor 2
   
    delay(50); 
}


Serial monitor output.
CODE: SELECT_ALL_CODE
11:39:07.042 -> L : 128     R : 128
11:39:07.088 -> L : 128     R : 128
11:39:07.134 -> L : 128     R : 128
11:39:07.228 -> L : 128     R : 128
11:39:07.274 -> L : 128     R : 128
11:39:07.320 -> L : 128     R : 128
11:39:07.367 -> L : 128     R : 128
11:39:07.413 -> L : 128     R : 128
11:39:07.460 -> L : 128     R : 128
11:39:07.553 -> L : 128     R : 128
11:39:07.599 -> L : 128     R : 128
11:39:07.646 -> L : 128     R : 128
11:39:07.692 -> L : 128     R : 128
11:39:07.739 -> L : 128     R : 128
11:39:07.786 -> L : 128     R : 128
11:39:07.833 -> L : 128     R : 128
11:39:07.925 -> L : 128     R : 128
11:39:07.972 -> L : 128     R : 128
11:39:08.018 -> L : 255     R : 255
11:39:08.066 -> L : 128     R : 128
11:39:08.111 -> L : 128     R : 128
11:39:08.158 -> L : 128     R : 128
11:39:08.253 -> L : 128     R : 128
11:39:08.299 -> L : 128     R : 128
11:39:08.345 -> L : 128     R : 128
11:39:08.392 -> L : 128     R : 128
11:39:08.439 -> L : 128     R : 128
11:39:08.485 -> L : 128     R : 128
11:39:08.532 -> L : 128     R : 128
11:39:08.625 -> L : 128     R : 128
11:39:08.672 -> L : 128     R : 128
11:39:08.718 -> L : 128     R : 128
11:39:08.764 -> L : 128     R : 128
11:39:08.811 -> L : 128     R : 128
11:39:08.858 -> L : 128     R : 128
11:39:08.951 -> L : 128     R : 128
11:39:08.999 -> L : 128     R : 128
11:39:09.045 -> L : 128     R : 128
11:39:09.092 -> L : 128     R : 128
11:39:09.138 -> L : 128     R : 128
11:39:09.185 -> L : 128     R : 128
11:39:09.278 -> L : 255     R : 255
11:39:09.324 -> L : 128     R : 128
11:39:09.370 -> L : 128     R : 128
11:39:09.417 -> L : 128     R : 128
11:39:09.464 -> L : 128     R : 128
11:39:09.511 -> L : 128     R : 128
11:39:09.558 -> L : 128     R : 128
11:39:09.651 -> L : 128     R : 128
11:39:09.698 -> L : 128     R : 128
11:39:09.745 -> L : 128     R : 128
11:39:09.792 -> L : 128     R : 128
11:39:09.839 -> L : 128     R : 128
11:39:09.885 -> L : 128     R : 128
11:39:09.979 -> L : 128     R : 128
11:39:10.028 -> L : 128     R : 128
11:39:10.074 -> L : 128     R : 128
11:39:10.121 -> L : 128     R : 128
11:39:10.166 -> L : 128     R : 128
11:39:10.214 -> L : 128     R : 128
11:39:10.308 -> L : 128     R : 128
11:39:10.353 -> L : 128     R : 128
11:39:10.400 -> L : 128     R : 128
11:39:10.446 -> L : 128     R : 128
11:39:10.493 -> L : 128     R : 128
11:39:10.539 -> L : 128     R : 128
11:39:10.586 -> L : 128     R : 128
11:39:10.679 -> L : 128     R : 128
11:39:10.726 -> L : 128     R : 128
11:39:10.772 -> L : 128     R : 128
11:39:10.819 -> L : 128     R : 128
11:39:10.865 -> L : 128     R : 128
11:39:10.912 -> L : 128     R : 128
11:39:11.005 -> L : 128     R : 128
11:39:11.052 -> L : 128     R : 128
11:39:11.100 -> L : 128     R : 128
11:39:11.146 -> L : 128     R : 128
11:39:11.193 -> L : 128     R : 128
11:39:11.240 -> L : 128     R : 128
11:39:11.287 -> L : 128     R : 128
11:39:11.379 -> L : 255     R : 255
11:39:11.426 -> L : 255     R : 255
11:39:11.473 -> L : 128     R : 128
11:39:11.520 -> L : 128     R : 128
11:39:11.566 -> L : 128     R : 128
11:39:11.614 -> L : 128     R : 128
11:39:11.707 -> L : 128     R : 128
11:39:11.753 -> L : 128     R : 128
11:39:11.799 -> L : 128     R : 128
11:39:11.846 -> L : 128     R : 128
11:39:11.892 -> L : 128     R : 128
11:39:11.939 -> L : 128     R : 128
11:39:11.986 -> L : 128     R : 128
11:39:12.078 -> L : 128     R : 128
11:39:12.126 -> L : 128     R : 128
11:39:12.173 -> L : 128     R : 128
11:39:12.221 -> L : 128     R : 128
11:39:12.267 -> L : 128     R : 128
11:39:12.315 -> L : 128     R : 128
11:39:12.363 -> L : 128     R : 128
11:39:12.458 -> L : 128     R : 128
11:39:12.505 -> L : 128     R : 128
11:39:12.551 -> L : 128     R : 128
11:39:12.599 -> L : 128     R : 128
11:39:12.645 -> L : 128     R : 128
11:39:12.692 -> L : 128     R : 128
11:39:12.739 -> L : 128     R : 128
11:39:12.832 -> L : 128     R : 128
11:39:12.878 -> L : 128     R : 128
11:39:12.925 -> L : 128     R : 128
11:39:12.972 -> L : 128     R : 128

What is causing these spikes? Is this normal or could the fault lie with the controller? What else can I try to check? Would Cytron be able to test out my code with a PS2 controller to see if output behaviour is the same?

Thanks,
Alan
alantch
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Posts: 2
Joined: Mon May 31, 2021 10:46 am

Re: Spikes in PS2 joystick readings

Postby ober » Sat Jun 12, 2021 1:43 pm

Try to slow down the SPI communication with the PS2 joystick.

Not very familiar with the protocol, but it should be using some sort of SPI communication to get the data from Joystick. It might improve the stability.

If you want to send back the Joystick, please do contact support@cytron.io
Ober Choo
Cytron Technologies Sdn Bhd
www.cytron.com.my
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ober
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Re: Spikes in PS2 joystick readings

Postby alantch » Mon Jun 14, 2021 2:46 pm

Hi Ober,

The PS2X library has a setting where the clock speed can be changed - but the spikes are still there. Returning the unit will only be logical if it can be proven that another identical PS2 controller does not produce the spikes on the same code (and with the CTRL CLK setting in PS2X_lib.h increased to 40 instead of 4). Otherwise, I'll just have to write some code to remove the spikes or implement a filter to smooth out the signal, which will decrease the responsiveness of the motors.

Thanks,
Alan
alantch
Greenhorn
 
Posts: 2
Joined: Mon May 31, 2021 10:46 am


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