10 years, 5 months ago.

how to display a word in lpc11u24?

i load this program in my LPC11u24 but it won't display, can any one help

  1. include "mbed.h"
  2. include "TextLCD.h"

TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x4); rs, e, d4-d7

int main() { lcd.printf("Hello World!\n"); }

We cannot magically know what is wrong with it without a proper description: What did you make, how did you connect it, and which results do you observe.

posted by Erik - 22 Nov 2013

2 Answers

10 years, 5 months ago.

The above code should work,

TextLCD lcd(p10, p12, p15, p16, p29, p30); // rs, e, d4-d7 

Asumming, you have connected up the screen correctly, Although, some LCD's need D0..3 set to logic levels, ... (LO, LO, LO, HI)

But most importantly, almost all 'older' LCD's will not work from 3V3, from MBED.

you can try connecting the supply for the LCD to USB 5Volts (pin 39 on MBED)

on an old board I have the connections are:

pinuse
1Gnd
25V0
3V-LCD
4rs
5R/W
6E
7D0
8D1
9D2
10D3
11D4
12D5
13D6
14D7
15LED +
16LED -

10 years, 5 months ago.

If there is enough voltage (5 Volts) then a dark line of pixels will be displayed, for the first 1/2 of the display,

Some displays need a negitive voltage on V-LCD.

what is the part number of the display, eg from farnell.

also show 'us' your connections ...

Lex