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4002 LCD alphanumeric display via I2C

2022-02-06
2022-02-27
1 2 > >> (Page 1 of 2)
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-06

    Hello ... Such displays are available for example on Aliexpress or eBay from "Surenoo Display". Did anybody test such a display, and in which mode ? And generally speaking which value do You use for I2C pullup's ? Thanks for any answer ...

     
    • Anobium

      Anobium - 2022-02-06

      Please be specific. Which product? There will be many Surenoo Dispalys.

       
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-06
     
  • Anobium

    Anobium - 2022-02-06

    The LCD is supported. But as I cannot work out what the I2C interface chip is... no idea. We support two I2C interface chips - is it one of those?

    A gamble unless you know the I2C interface chip.

     
  • Anobium

    Anobium - 2022-02-06

    So, it could be LCD_IO 12

    See the Help for LCD_IO 12, that is PCF8574.

     
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-06

    And concerning the resistors ?

     
    • Anobium

      Anobium - 2022-02-06

      4k pulls on both i2c lines.

       
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-06

    Thanks ... I will test and publish the results as soon as I get the component. The only difficulty is that the standard fonts are English and Japanese, so if I wanna use French diacritic lower case chars (é, ô), maybe I will need to create them.

     

    Last edit: Bertrand BAROTH 2022-02-06
  • Anobium

    Anobium - 2022-02-07

    Your issue will be the implementation/connection of the PCF8574 to the LCD. It may not work out of the box but it will be resolvable.

    :-)

     
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-08

    I saw in the LCD_12 section that 2 ways to connect the data lines seem to exist ... If I see "garbage" I will first try this suggested modification and in worse case contact the seller to know how the lines of the LCD are connected to the I2C adapter.

     
    • Anobium

      Anobium - 2022-02-08

      Your route to sucess.

      1. Try. You wont blow up the devices.
      2. Ask the supplier. Good luck with this as they will point you to the Arduino code libraries.
      3. Ask back here... I will need a hi-res photo of the i2c and the connection to the LCD.

      it will be fun.

       
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-08

    Today I got the mail that the board has been shipped. I will use the old principle : Plug and pray ! At least I have the pinouts both of the adapter and LCD display (look at the datasheet of the adapter, attached), so maybe that I could see the corresponding connections between the LCD and the pins of the SMD interface chip (multimeter ? ) ; and with the datasheet of the IC, I should understand how the systems are connected and if necessary modify the assignments of the pins in the software ... In the worst case and with some "dremelling" and desoldering, I should be able to convert it back to a "parallel" mode display : at least my money won't be completely lost ...

    :)

     

    Last edit: Bertrand BAROTH 2022-02-08
  • stan cartwright

    stan cartwright - 2022-02-11

    I used an i2c to 16 channel adaptor, l used it to drive 12 servos and it's gcb supported-- PCA9685.
    The bought gear I have like a frequency gen is so retro with a 2 line display.
    My component identifier testers uses a glcd. GCB supports many. More fun than 2 line.

     
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-12

    I admit that a GLCD has really more possibilities, but for my application I need only a text display ! Using a GLCD for this purpose is like taking a dozer to crack peanuts ...

     

    Last edit: Bertrand BAROTH 2022-02-12
  • Geoffrey Younger

    They look like two modules I got from EastRising LCD a couple of years ago. I think you will be pleasently surprised. They look like modules manufactured by CJMCU ! I've attached a file I used
    for testing an 8x2 LCD. Hope this helps .
    Cheers

     
  • stan cartwright

    stan cartwright - 2022-02-12

    Anobium has put much effort into glcd,
    Which display is better?

     
  • stan cartwright

    stan cartwright - 2022-02-12

    The component tester cos £7 or less. It does electrolytic capacitor ESR is SO useful.
    It's got an avr something on board that does everything. Displays like ili9341 are cheap and well supported by gcb.
    Anobium has added test pixel cos I just asked him. My more interesting application of using it.
    https://www.youtube.com/watch?v=SGJFApFqx1Q
    Anobium also sorted the ili9341 touch screen capabilities also for the lgt238.
    He's a star. All his work, I think it's a well supported cheap display. Needs a few pins but not many.
    Every device in my house that uses a display does not use a 2 line lcd.

     
  • stan cartwright

    stan cartwright - 2022-02-12

    Bertrand -- get a glcd sir. The ili9341 is well supported by gcb but the ones I use are 3.3V logic . They do need a logic level converter unless you use a pic at3.3v supply or a lgt328 which uses 3.3v logic. Anobium also wrote a xor plot for ssd1306 just cos I asked . How cool is that?
    As is this is easy. https://www.youtube.com/watch?v=axHTYdH9WW8

     

    Last edit: stan cartwright 2022-02-12
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-13

    Thanks for all answers, but a glcd would only be of interest for me coupled with a touch sensitive function. Unfortunately such devices cost an arm and a leg and I didn't find any powered with 5v (I use ATMega8515 or 162 if necessary), only 3.3v (I looked at Reichelt and AliExpress). Surenoo has several models around 60 Euros but there are no technical details concerning connecting and supply voltage.

     
  • stan cartwright

    stan cartwright - 2022-02-14
     

    Last edit: stan cartwright 2022-02-14
  • stan cartwright

    stan cartwright - 2022-02-14

    Bertrand- When my camera has recharged I'll do a quick youtube vid of ili9341 and the touch demo on a lgtnano328.
    The display must have the xpt2046 chip... some don't.
    I have 4 of these displays and they all need 3.3V logic so using a ttl converter adds more wiring and looks messy. As I said a pic running at 3.3V will have 3.3V logic. I like the lgt328 as it uses 3.3V logic when powered from usb 5V.
    I stripped the touch demo to just drawing small circles. Seeing if the x,y touch co-ordinates were within any boxes on the screen would be easy. That's why I'm recommending this to you.
    They are cheap displays. Much cheaper than a Nextion and I think less work to get them going... you have to learn nextion ide.
    OK here's the short video https://www.youtube.com/watch?v=4XfjQE5b5bc
    Anobium had to do extra work for the ili9341 touch to work with lgt328 as it was too fast for hwspi... but he sorted it so the screen is hwspi , which is fast and the touch uses swspi. Amazing guy.

     

    Last edit: stan cartwright 2022-02-14
  • stan cartwright

    stan cartwright - 2022-02-14

    Using an Arduino 328 nano and a logic converter. Messy wiring and not the touch wires connected.
    The display works fine with arduino nano/uno 328.
    It's twice as fast using a lgt328.

     
  • stan cartwright

    stan cartwright - 2022-02-14

    The displays are cheap and well gcb supported. You could make one a fake 2 line display for a "laugh". Thing is they are so versatile with the glcd commands and use few pins imho brill!
    I been messing with trig to do dials. Results look ok. 2 line displays are so retro. Can't do out.

     
  • Bertrand BAROTH

    Bertrand BAROTH - 2022-02-14

    I am afraid that this will become a "gaseous plant" ... The thing which bothers me most is the level conversion, despite of the fact that I found some UNIDIRECTIONAL solutions here :
    https://next-hack.com/index.php/category/electronics-tips/logic-level-conversion/
    Finally I think I will stay with my "old fashioned" 4002 display and mechanical push-buttons ! For a time I had even considered displaying numeric values with ... NIXIES ! :)

     

    Last edit: Bertrand BAROTH 2022-02-14
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