Display corrupts when a string containing "Mod" is printed

[per1234]

Moved from https://github.com/arduino/Arduino/issues/9887 by @Camo2000

I have found an issue with the LCD display Output, it works fine until you add the word "Mode" as a string. The display then corrupts and I can not see why unless there is a method to control the LED display with text. However if you use any string with the word in it, it still corrupts:-

• "Mode"
• "Edit Mode"
• "Active Mode"

All fail.

String MyTitles[ARRAYSIZE]={"Mode", "Effect", "Pallete", "Sin8", "Sin16", "Speed", "LED Spacing"}; this fails if Mode is in the list

Hope some of you can replicate this.

[per1234]

From per1234 on 2020-03-18:

Please post your full sketch.

[per1234]

From Camo2000 on 2020-03-18

#define ARRAYSIZE 7
String newtit[ARRAYSIZE]={"Apple","Effect","Pallete","Sin8","Sin16","Speed","LED Spacing"};
int iValues[ARRAYSIZE] = {1,2,3,4,5,6,7};
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 7;// initialize the library by associating any needed LCD interface pin
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);// with the arduino pin number it is connected to

void setup() { 
  Serial.begin(9600); 
  lcd.begin(16, 2); // set up the LCD's number of columns and rows:
  lcd.print("Display Active"); // Print a message to the LCD.
  delay(2000);
}
void loop() {
  int iSelection=0;
  lcd.setCursor(0, 1);
  String message =(String)"A" + iValues[iSelection] + " " + newtit[iSelection] + "          ";
  Serial.println(message);
  lcd.print(String(message));
  delay(5000);
}

[per1234]

From Camo2000 on 2020-03-18

just change the word "APPLE" to "Mode" and the LCD will fail or any word in the array once accessed. use int iSelection=0; to select the array space Apple is 0 but you can put the word Mode anywhere in the array and when accessed it fails. It also fails on the word "Mod" maybe this is what it is picking out PLEASE NOTE: the serial.print works fine, it is the lcd.print that fails

[per1234]

From per1234 on 2020-03-18:

Which board are you using?

[per1234]

From Camo2000 on 2020-03-18

it is the standard LCD board 1602A

[per1234]

From per1234 on 2020-03-18:

Which Arduino board. For example: Uno, Leonardo, Mega, MKRZero, Nano 33 IoT...

[per1234]

From Camo2000 on 2020-03-18

Uno R3, but the board seems to be working the LCD only fails if a word containing this sequence "MOD" are sent to the LCD

[per1234]

I was not able to reproduce this issue. It might be specific to one particular variant of the LCD driver.