Use as follows

SoftwareSerial mySerial=SoftwareSerial(rx, tx, true); //Rx, Tx pins

The parameter  true (lower case) enables reading inverted serial input

Wire.begin() added in setup().  Random write still persists

I assumed it would be called in the lcd.init() since this is an i2c device.
Nonetheless, I'll give it a sot and see what shakes.  -Thanks.

I am running a simple sketch to display captured analog values to am i2c  NHD LCD.. and am getting unexpected results..  After about 5 minutes, the program writes the analog values at unpredictable locations.  On occasions the write is not even numbers.  It's almost as if the LCD clear and position is lost when the next write happens.  The Arduino code is straight forward enough, I wonder if there is a problems with the i2c LCD display or the NHD i2c LCD library.  See sketch code here.  Appreciate your thoughts

#include <Wire.h>
#include <LCDi2cNHD.h>
#include <stdio.h>
#include <stdlib.h>

LCDi2cNHD lcd=LCDi2cNHD(4, 20, 0x50>>1, 0);

int sensor1Pin = 1;    // select the input pin for the potentiometer
int sensor2Pin = 3;    // select the input pin for the potentiometer
int sensor1Value = 0;  // variable to store the value from the sensor
int sensor2Value = 0;  // variable to store the value from the sensor
int delayValue;

void setup() {
  lcd.init();
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("ADC1.angle");
  lcd.setCursor(1, 0);
  lcd.print("ADC2.angle");
  pinMode(ledPin, OUTPUT);  
}

void loop() {
  char s[10];
  float angle;
  // read the value from the sensor:
  sensor1Value = analogRead(sensor1Pin);  
  sensor2Value = analogRead(sensor2Pin);
  angle=360.0*float(sensor1Value)/1024.0;
  dtostrf(angle, 5,2,s);
  lcd.setCursor(0,12);
  lcd.print(s);

  angle=360.0*float(sensor2Value)/1024.0;
  dtostrf(angle, 5,2,s);
  lcd.setCursor(1,12);
  lcd.print(s);
  delay(100);                  
}

There could be a few things messing you up..
Most servos I have fooled with do not like to be driven to their limits (min, max).  
Limit numbers are unique to each servo model and brand
So you have to increase Min number and decrease Max number until your servo behaves.
Heavier servos likely draw down more current (especially if you have a load on the servo)

In any case, I have attached a simple servo sweep code which works fine on my nano.  Hopefully it will run on your board.. do vary the digital pin you connect the servo to.  

Good luck!

PS> never mind the comments.. they are a carry over from the original sweep code.

#include <Servo.h>
 
Servo myservo;  // create servo object to control a servo
                // a maximum of eight servo objects can be created
 
int pos = 0;    // variable to store the servo position
 
void setup()
{
  myservo.attach(12);  // attaches the servo on pin 9 to the servo object
}
 
 
void loop()
{
  for(pos = 50; pos < 150; pos++)  // goes from 0 degrees to 180 degrees
  {                                  // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position
  }
  for(pos = 150; pos>50; pos--)     // goes from 180 degrees to 0 degrees
  {                                
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(25);                       // waits 15ms for the servo to reach the position
  }
}