antonio mbed

Important changes to forums and questions

All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.

8 years, 6 months ago.

LCD 16X2

Dear All,

Anyone knows if the LCD 16x2 library has changed?

Not it can not display the character in the right orders

Any helps please

Regards

Antonio

1 Answer

Wim Huiskamp
8 years, 6 months ago.

Which lib are you using and how is it connected to your lpc1768 mbed?

Dear, thank you for your replay.

I am using this library:

https://developer.mbed.org/components/HD44780/

The connection is: 1 > 0V 2>Vcc 3V, Vout 3> 0V via potentiometer 5k 4> p15 5>0V 11>p17 12>p18 13>p19 14>p20

Thank you so much for your help

posted by antonio mbed 04 Nov 2015

So your connection is:

1> 0V

2> Vcc 3V, Vout

3> 0V via potentiometer 5k

4> p15

5> 0V

11> p17

12> p18

13> p19

14> p20

In your list it looks like pin6 on the LCD is not connected. That pin is for E (enable) and should be connected to p16 of the lpc1768 mbed. Make sure that all pins are connected correctly.

Make sure your display has the default pinout for an HD44780 16x2 (check datasheet, what is the typenumber?). Also make sure that your display works for 3V3 powersupply . Some displays need 5V powersupply, but will work with 3V3 data and controlsignals.

It may also be better to use a potmeter with ends connected to 3V3 and 0V and wiper to pin 3 of the LCD. A single ended potmeter may have less stable contrast.

Code for connections above should be:

TextLCD lcd(p15, p16, p17, p18, p19, p20); // rs, e, d4-d7
posted by Wim Huiskamp 04 Nov 2015