LCD I2C display on Giga

Official Hardware Mega GIGA R1 WiFi
1

Hi all,

struggeling a bit with getting an LCD display to work.
Had this display work on my UNO and wanted to reuse it.
Connected it to I2C1.

As soon as I initiate the display in the code, the Giga crashes (red led blinking 4 times fast, 4 times slow). When I scan the I2C, I find the correct address.

I tried different libraries and get the same results.

#include <Wire.h>
#include <LCD_I2C.h>

#define WIRE Wire1
LCD_I2C lcd(0x27, 16, 2); // Default address of most PCF8574 modules, change according

void setup() {
  WIRE.begin();
  lcd.begin(false);
  lcd.display();
  lcd.backlight();
}

void loop() {
}

Any idea whats going on?

Cheers

2

I'm not familiar with the Giga but the Giga is a 3.3V board; you're LCD is more than likely a 5V device (as it used to work on an Uno).

3

Could be wrong voltage as @sterretje mentioned,

I could be wrong, I have not played with these libraries, but wondering if you are using the
wrong Wire object?

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image724×430 55.1 KB

You mentioned I2C1, which I believe is the Wire1 object. The Wire object I believe uses the
pins I2C over to the right.

It also looks like the LCD_I2C library is hard coded to use the Wire object. Some other
libraries have ways to tell it which of the wire objects to use.

4

Hi,
Thank you for the hints. I think that the voltage is a prime suspect. I'll test it and see if this already fixes the issue.

From my understanding it should be the write wire. Reading the address with a address scan code results in getting the correct address for the display.

I will also look again into the library, but I thought that the begin(false) should take care of that.

Cheers