Hello all,
I have a LCD2004A 20x4 module, without I2C contoller.
how can I use it with Arduino UNO.
Sorry if this is a repeated thread. I have searched in google and Arduino form, but no luck.
I have another HD44780 16x2, it was working fine with my UNO.
I needed little more space for the display, then I upgraded to LCD2004A 20x4.
I thought both are compatable but after changing its not working.
please help me.
Well, I suppose if you explain "not working" in terms of what it does or does not show - illumination, line of blocks, whatever - as well as a perfectly focused photograph of your set-up with all wires and parts clearly visible as they terminate on the modules and show that as a link in the text, not an attachment, then we might be able to start.
The best way to do this is to take it outside in full daylight but not direct sun and use a digital camera at least a metre away from directly above (or very slightly offset to ensure all the connections are able to be distinguished) using the (actual) zoom to just include all parts of the assembly.
And having first read the instructions for submitting queries, then post your code -the non-working version and perhaps the working version so we can see what you might have changed. (It makes perfect sense incidentally, to try the unchanged working code on the alternate display, having checked again that it still works on the 1602.)
You should be able to substitute your 20x4 for the 16x2 and have it function without making any changes to your sketch. Just get the 16x2 working, turn off the power and swap modules, and then reapply power. Make sure you reset the Arduino if it wasn't powered down along with the LCD module.
You may have to readjust the contrast potentiometer, but other than that you should get the same display on the top two lines of your 20x4 as you had on your 16x2. After you get things working you can change the lcd.begin(...) statement to get the cursor positioning working correctly for the bottom two rows.
Don