problems with LCD driver

Posted on
  • Hi Kim,

    Did you actually have problems, or do you want me to delete this post?

  • I still have quite a lot of issues with the PCD8544 display. At times, it just works. And whenever it is working, I can do with it whatever I want. As soon as the power to the Espruino is cut though it's a gamble whether I'll get access to the display again (without changing any of the cables). The only solution seems to be to power down and power up the Espruino repeatedly until it finally starts working again. The only error I get in the latest version is INTERNAL ERROR: Timeout on SPI RX, but I also seem to get this error when the display is working properly, so I don't know if that is of much use ...

    PS: sorry, for the empty post at first, something must have gone wrong.

  • Hmm, that's odd. I haven't had any troubles but it could be something to do with the reset. Do you wait until a few ms after startup before your write to the screen?

    The internal timeout thing is something I'll look into, but you can get around it by specifying a baud rate - maybe 100000.

  • Well, I still use the code example you provided to initialise everything so I think that the waiting is indeed sufficiently dealt with. The baud rate I use has one more 0 than yours, but given that you warn about rates below 1Mhz I assume that this is what you meant.

    When the screen isn't working though, I am capable of turning the backlight on and off, so I assume it must be an issue related to the initialisation of the screen.

  • The backlight isn't connected to the screen at all really - it's just an LED that's controlled from an IO pin.

    It's strange - I've heard that the displays are a bit picky with reset, but apart from issues when I was initially developing the module, it's all seemed pretty reliable.

  • Post a reply
    • Bold
    • Italics
    • Link
    • Image
    • List
    • Quote
    • code
    • Preview

problems with LCD driver

Posted by Avatar for Kim @Kim