Choose an alphanumeric LCD display

Discussion in 'Embedded Systems and Microcontrollers' started by Albe, Aug 20, 2012.

  1. Albe

    Thread Starter New Member

    May 16, 2010
    I'm doing a project of a small unit for my tractor, this contain a pic, rtc, digital thermometer and a hall sensor for read rpm. All the data will display on alphanumeric lcd.
    I have to work both day and night, so I need a lcd with backlight.
    I would read correctly the lcd on day without turn on the backlight and on night turn on the light.
    What kind of lcd I have to choose?
    I see this: Link
    Can go?
    Ps. I have a display with backlight but i can't read it without turn on backlight.
    I apologise in advance for my poor/bad English.
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    That looks like a fine choice: two lines each having 16 characters. There are separate pin to turn on a LED backlight. You might find out leaving it on in the day time is OK, unless you are worried about the (battery?) power it needs. I've used a transistor driven by a PIC to turn these backlights on and off.
  3. Albe

    Thread Starter New Member

    May 16, 2010
    I have already used a lcd so I know this.
    I'm sorry but I didn't understand well what you want say.
    I haven't nothing problem of power, I have a battery of 120Ah and a alternator of 750W.
    My problem is know if it's readable on day without power the backlight led.
    I'm not sure of this becouse, as said before, I have used a lcd that you can't read it without led powered.
    Thank you very much.
  4. Albe

    Thread Starter New Member

    May 16, 2010
    Nobody did some similar experiment/project?
  5. JohnInTX


    Jun 26, 2012
    If what you are asking is will the display will be readable in daylight, it will be readable.

    Most LCDs are readable primarily by ambient light. For best contrast and viewing angle, look for 'supertwist' STN / FSTN displays.
    Last edited: Aug 25, 2012
    Albe likes this.
  6. absf

    Senior Member

    Dec 29, 2010
    So you're doing a project using PIC to display time, temperature and RPM of your tractor on LCD....Which PIC are you using? Did you have any experience with PIC before? Without knowing your electronics background, it is hard to give you any pointer.....

    May be you can take a look here.
    There are projects like PR#3 - interfacing between 16F877A with LCD,
    PR#12 - RTC on LCD
    PR#11 - Temperature control using LM35.

    All schematics and source codes in Hi Tech C are free to download.
    There is also a tutorial section where there are more simple projects.

  7. takao21203

    Distinguished Member

    Apr 28, 2012
    I have a new revision for character LCD interface here:

    It is 4-bit mode, and 16f1824 is used. But also works on 18F PICs.

    Most character LCDs can be read w/o backlight. Except the dark blue one's maybe. TFT LCDs in general need backlight to be readable.
  8. Albe

    Thread Starter New Member

    May 16, 2010
    The lcd that I linked it's a FSTN than it should be fine.

    Thank for the information. I have good knowledge on PIC.
    I have already made the software and test it on easy pic 5, it work.

    The lcd on easypic5 is Blue/white and without backlight I can't read it, but the lcd that I have to buy (linked before) isn't blu.

    PS. The first version of project it's this.
    Thank for all answers.