16 x 2 alphanumeric LCD display is not working

[shindehari]

Hi,

I have successfully tested the 16x4 LCD display with my C code. I was trying to use the same code for 16x2 LCD display and it is not working. I am using same hardware for 16x2 and 16x4 LCD display.

Please let me know is there anything need to be changed for 16x2 LCD display.

 

[BobK]

Not working is not very descriptive.

Bob

 

[Harald Kapp]

I am using same hardware for 16x2 and 16x4 LCD display.

That's not possible. a 2 line display has hardware differebt from a 4 line display.
Let us at least know the types (part numbers) of your displays .

 

[kellys_eye]

The 2 and 4-line displays are via the same pinout connector but use different (Additional) registers for the different lines in use.

The OP may simply have failed to readjust the contrast setting for the different devices.

 

[shindehari]

Thanks for the reply,

Please find attached display connector hardware for LCD display.

LCD display model number is LCD1602

 

[BobK]

Are you using the busy signal or using delays between commands? If the latter, up the delays a bit and see if it works any better.

Bob

 

[hexreader]

I reckon kellys_eye hit the nail on the head.

Pin 3 should be connected to a contrast control pot, not left open.

 

[kellys_eye]

Your wiring diagram shows pin 3 as unconnected. This should have a variable DC voltage (from the wiper of a 10k pot connected across the 5V supply) to allow adjustment of the screen contrast.

It's a simple fit and ESSENTIAL for correct operation.

Hmmmph - typing on a tablet is sssllloooowwwwww!