LCD Keypad shield wierd characters [SOLVED]

Hi all.
Few days ago i started playing with LCD Keypad shield from aliexpress (aliexpress.com/item/32506580739.html)
and got problem with “wierd characters” (photo1)

I’m using Arduino UNO R3, all “soldering points” looks good, i’m using DSO203 digital osciloscope and some testing sketches to test pins and voltages - all looks fine.
I have 2 lcd shields, and both behave same. i have other arduino boards, but i was planing using uno for this project - to skip soldering, so still wish to keep this combination of “board-shield”

I’v googled a lot, tested 4/8 bits modes - i see defference, but still “something wierd”, but no “hello world”
I hope, i just miss some small detail, but already 2 days with no clue

(ubuntu, atom+platformio)

simple “hello world” sketch

#include <Arduino.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

void setup() {
  // lcd.begin(16, 2);// optional uint8_t charsize = LCD_5x8DOTS)
  lcd.begin(16, 2, LCD_4BITMODE);// optional uint8_t charsize = LCD_5x8DOTS)
  // lcd.begin(16, 2);
  lcd.setCursor(1, 1);
  lcd.print("hello, world!");
  delay(1500);
}

void loop() {
  // Turn off the display:
  lcd.clear();
  lcd.setCursor(1,1);
  lcd.print(millis()/1000);
  // lcd.noDisplay();
  // delay(500);
   // Turn on the display:
  // lcd.display();
  delay(500);
}

pins test sketch:

#include <Arduino.h>

int pin = 0;
int max = 10;
int i=0;

void setup()
{
  Serial.begin(9600);
  Serial.println("Starting");
}

void blink(int pn,int times = 2, int delay1=500, int delay2=2000)
{
  pinMode(pin,OUTPUT);
  for (i=0;i<times;i++)
  {
    digitalWrite(pin,HIGH);
    delay(delay1);
    digitalWrite(pin,LOW);
    delay(delay1);
  }
  delay(delay2);
}

void loop()
{
  Serial.print("testing pin [");
  Serial.print(pin);
  Serial.println("]");
  blink(pin);
  pin++;
  if (pin>13) pin=0;
}

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[![

](https://forum.arduino.cc/index.php?action=dlattach;topic=660594.0;attach=343301)

photo_2020-01-24_15-14-19.jpg

photo_2020-01-24_15-27-06.jpg

Paul__B, thanks

I really do not know what your problem is but I have seen similar problems when the wiring was not 100% correct. I think it is in the data lines to the display. It is also possible it is not programmed in the mode you are using 4/8 bits. This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil

gilshultz, thanks

i was playing with configuration on photos, but couldn't solve it.
so i just took another board, solder main pins and everithing got perfect!

after getting "working configuration" i try to make small research disconnecting "data pins" one by one, trying to get same problem as i got before, but was no success.

so, i has no clear answer about "what was going", but i can recommend for anyone having same issue - take another board and rewire..

abrakadobr:
after getting "working configuration" i try to make small research disconnecting "data pins" one by one, trying to get same problem as i got before, but was no success.

Yes, I was thinking about the possibility of a missing connection, but given that you were using a shield mounted by its pins to a UNO, a "stuck" pin (to Vcc or ground) or more likely, two data pins shorted together would be more likely.