Stability problem (arduino nano)

[jeremy67]

Hello,
In an associative framework for sick children, I automate an Ironman cosplay.
The project consists of managing the opening of the visor of a helmet via 2 sg90 motors, 2 leds for the eyes, all controlled by an RF433 remote control.

The opening sequence works perfectly with in dry contact.
When I add the RF receiver the opening and closing also works but I see something weird.
The motors vibrate slightly and the LEDs also flash slightly. But as soon as I unplug my receiver, these small oscillations disappear ... (see video: VID_20210420_190025.mp4 - Google Drive)

Currently the nano is powered via the usb port for tests via my pc (I tried with a 2A phone charger, same problem), eventually the nano will be powered by a 9v rechargeable battery (I need a battery life of 6 to 8 hours max for hospital visits)

Here are the receivers that I use for the tests (identical problem with the 2)

code :

#include <RCSwitch.h>
RCSwitch mySwitch = RCSwitch();
#include <Servo.h>
Servo myservo;  // create servo object to control a servo

#define INTERRUPTEUR 10
#define OEILG 14
#define OEILD 15
bool memoInter=false;
int bp1 = 0;            
int bp1Mem = 0;         
int ledOn = 1;          

char str_BPH[]="278308";
char str_BPB[]="278305";
char str_BPS[]="278306";
char str_reception[]="";

void setup() {
  //Serial.begin(9600);
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo.write(0); 
  pinMode(INTERRUPTEUR, INPUT); //interupteur (D10)
  pinMode(OEILG, OUTPUT); //oeil 1 (A0)
  pinMode(OEILD, OUTPUT); //oeil 2 (A1)
  analogWrite(OEILG,0);
  analogWrite(OEILD,0);
  mySwitch.enableReceive(0);  // Receiver on interrupt 0 => that is pin #2
}


void loop() {
  
  bp1 = digitalRead(INTERRUPTEUR);
  
  if (mySwitch.available()) { 
    sprintf(str_reception,"%ld", mySwitch.getReceivedValue());
    if(strcmp(str_reception,str_BPH) == 0  || strcmp(str_reception,str_BPB) == 0 || strcmp(str_reception,str_BPS) == 0){
    bp1=1;
  }
  mySwitch.resetAvailable();
  }
  
  if (bp1 != bp1Mem){
    bp1Mem = bp1;
    
    if (bp1 == 1) {
      
     ledOn = !ledOn;
      //Serial.println("here");
     if (ledOn == 1) {
      analogWrite(OEILG,0);
      analogWrite(OEILD,0);
      myservo.write(0);
    
     }else{
      myservo.write(130);
      delay(800);
      analogWrite(OEILG,511);
      analogWrite(OEILD,511);
    }
   }

  }
bp1=0;
}

[J-M-L]

Hi

how are the servo wired ? do they take power directly through the Arduino 5V pin?

[jeremy67]

yes

[jeremy67]

whether in open or closed position, the motors vibrate and they have little tones
but if I remove the receiver or if I order the code of the receiver, everything is stable

[J-M-L]

That's probably too much current drawn through the Arduino pins.
You might need to power the board on one side and the motor separately, joining GND

[slipstick]

@jeremy67

eventually the nano will be powered by a 9v rechargeable battery (I need a battery life of 6 to 8 hours max for hospital visits)

9V battery is a bad idea. Arduino and servos both run at 5V so what you need is a rechargeable 5V powerbank. Even then you will need to choose carefully to get a long run time.

Steve

[jeremy67]

I tested by adding a separate power supply for the power part. The problem is still here. I replaced the nano with an uno, but the problem remains the same. I am lost there. Is it possible that there is a conflict with the servo and rc-switch libraries?

[J-M-L]

@jeremy67

Is it possible that there is a conflict with the servo and rc-switch libraries?

try with ServoTimer2 to make sure in case it's a timer1 conflict (I use RadioHead and never used RCSwitch)

[jeremy67]

I will test with servotimer2, thanks. I tried RadioHead but I don't know why it doesn't work. I tested with pin 2 and 11, without success

[jeremy67]

I just tested the servotimer2 library, but I have the same problem. I also retested radiohead, but it doesn't work.
Here is a picture of the behavior of the engines: VID_20210421_162854.mp4 - Google Drive

I'm lost and I'm tearing my hair

[jeremy67]

if I remove the line from the code: mySwitch.enableReceive(0); or if I unplug the receiver, the motors no longer move