LCD with level shifter problem

Other Hardware General Electronics
1

Hi.

I tryy to use an LCD 2004a screen with arduino DUE. I tried with level shifter (clone from Sparkfun bi-directionnal.

I test the screen with an uno and it work, but when I try with DUE and the level shifter, it only display full black character.

Is there a current limit I could have bust ? I previously test the level shifter with no load, the got 5V but if I read the rs pin when plug in, I read 3.4V.

I do not have the datasheet of the LCD, I buy it from amazon here

It is not clear witch exact model it is, It only have a label "2004A" on the back...

dont now what to do next.

Thanks.

Nitrof

2

A schematic showing how everything is wired may help as well as a photo or 2. I have use the same type of display (5V I2C 4x20 LCD) with MOSFET level shifters and an ESP8266 (3.3v) with good success.

3

I use this connection.

With the DUE, I try the same thing and with all 8 data pin. on those eight pin and enable and RS pin, I put the level shifter:

The arduino is on the LV side, 3.3V and ground, all LCD pin on HV side, 5 and gnd.

4

humm... tested all pin by making a sketch writing all HIGH, and every thing was working, after reload the setch and now the LCD work. Maybe a bad connection into the proto board...

All that said, working.

Thanks.

Nitrof