1602 LCD Display, no text


#1

Hello, new to XOD and excited about working with visual programming.
I tried the basic hello world tutorial (link below) for the 1602 display and have an issue.
The program downloads without errors and the screen is lite and can adjust the contrast but no
text. I am using an Elegoo Uno R3 and the 1602 LCD that came with the kit. The LCD doesn’t appear to have the i2c board. I’ve triple checked the wires and am at a loss at this point. Please, any suggestions, things to check.

LCD Tutorial

Thanks


#2

Update …Display is 1602a


#3

Hello and welcome!

I would recommend checking whether you get any characters displayed without XOD, using only the very basic examples bundled with the LiquidCrystal library in Arduino IDE. If the display work there, we’ll investigate further.

If not, it’s a hardware problem (you’ll need to check the wiring for the fourth time). Perhaps, its contrast set up improperly. Various models of LCDs have a different meaning of the contrast pin. For maximal contrast some require the pin to be pulled up to Vcc, others require pull-down to the ground, while yet others require pulling to exactly ½Vcc. If you did not wire the contrast pin correctly, the display may actually show text but with a zero-contrast and you just don’t see the digits. When the backlight is enabled you should see rectangle outlines, if you don’t, the problem is likely in the contrast.


#5

I ordered a spare 1602a board and will give it another try this evening and update…

Thanks for the responses


#6

I was able to get an i2c board working, not sure what was wrong with the other display.

On a separate note:
I was looking for a way to send different strings to the display based on different button inputs?
I’ve been looking thru the blocks and haven’t seen any way to drive a string to LCD base on a
button or switch input.

Thanks


#7

xod/core/select is probably what you want.


#8

Thanks, i also found the xod/core/if-else seems to work with a button input.

Is there a simple example of the xod/core/select? I’m struggling a bit with the application of it.

Thanks


#9

Select returns the X value associated with the last S pin to receive a pulse (or right-most X value if no pulses have been received).

If-else will work if you only want the text to change while the button is pressed (releasing the button will return to original text).

Select will return text for the last button pushed until another button is pushed (assuming S pins are wired to buttons). Select will also handle more than one button.