Diodo Laser Head | mini moduli a diodi laser a 1 punto da 650 nm, 5 mW, 5 V

Buongiorno
mi serviva una conferma, se devo utilizzare questo diodo con arduino non devo mettere alcun resistore giusto?

can anyone please help me,
i am working on weight sensor i.e., hx711 with 10kg load cell on arduino.It is showing some weight in serial monitor when no weight is also placed and that output is in -ve values. Readings are not constant even after sometime when trying to take calibration values.so,unable to get the calibration properly and no accurate weight.This is my code for calibration.

#include "HX711.h"

#define DOUT A1
#define CLK A0

HX711 scale;
//long val=0;

float calibration_factor = -16454.36;

void setup() {
Serial.begin(9600);
Serial.println("HX711 calibration sketch");
Serial.println("Remove all weight from scale");
Serial.println("After readings begin, place known weight on scale");
Serial.println("Press + or a to increase calibration factor");
Serial.println("Press - or z to decrease calibration factor");

scale.begin(DOUT, CLK);
scale.set_scale();
scale.tare(); //Reset the scale to 0

long zero_factor = scale.read_average(); //Get a baseline reading
Serial.print("Zero factor: "); //This can be used to remove the need to tare the scale. Useful in permanent scale projects.
Serial.println(zero_factor);
}

void loop() {

scale.set_scale(calibration_factor); //Adjust to this calibration factor
Serial.print("Reading: ");
Serial.print(scale.get_units(), 3);
Serial.print(" kgs"); //Change this to kg and re-adjust the calibration factor if you follow SI units like a sane person
Serial.print(" calibration_factor: ");
Serial.print(calibration_factor);
Serial.println();

if(Serial.available())
{
char temp = Serial.read();
if (temp == '+' || temp == 'a')
calibration_factor += 10;
else if (temp == '-' || temp == 'z')
calibration_factor -= 10;
}
}

so,please tell me how to get proper +ve calibration values .It has to show zero when no weight is placed and proper weight when weight is placed.
NOTE:
calculated resistance values for load cell. R1/R2=R3/R4. Already load cell is changed.Values are keep on increasing continously.

this is the ouput i got when no weight is placed

Reading: -1.167 kgs calibration_factor: -16454.36
Reading: -1.169 kgs calibration_factor: -16454.36
Reading: -1.174 kgs calibration_factor: -16454.36
Reading: -1.182 kgs calibration_factor: -16454.36
Reading: -1.179 kgs calibration_factor: -16454.36
Reading: -1.184 kgs calibration_factor: -16454.36
Reading: -1.187 kgs calibration_factor: -16454.36
Reading: -1.192 kgs calibration_factor: -16454.36
Reading: -1.188 kgs calibration_factor: -16454.36
Reading: -1.183 kgs calibration_factor: -16454.36
Reading: -1.170 kgs calibration_factor: -16454.36
Reading: -1.166 kgs calibration_factor: -16454.36
Reading: -1.161 kgs calibration_factor: -16454.36
Reading: -1.160 kgs calibration_factor: -16454.36
Reading: -1.175 kgs calibration_factor: -16454.36
Reading: -1.177 kgs calibration_factor: -16454.36
Reading: -1.179 kgs calibration_factor: -16454.36
Reading: -1.182 kgs calibration_factor: -16454.36
Reading: -1.188 kgs calibration_factor: -16454.36