Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 4 of 4

Thread: teensy 3.6 and lcd display

  1. #1
    Junior Member
    Join Date
    May 2018
    Posts
    1

    teensy 3.6 and lcd display

    Can anyone suggest an LCD display (2 x 16 is big enough) for use with the teensy 3.6? All the ones I found so far use +5v logic, not the 3.3v logic the 3.6 puts out.

    Fred

  2. #2
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Location
    Ayer Massachussetts
    Posts
    2,992
    Sparkfun sells an OLED display that fits on top of a Teensy:


    Adafruit sells an OLED display that fits into their feather system. For a Teensy, you would get the feather adapter, and the display:


    In addition, Adafruit sells other OLED displays, including:


    You can get clones of this display on ebay much cheaper:


    Note, if you have an i2c display, you may need 2 pull-up resistors, one between pin 17 and 3.3v, and the other between pin 18 and 3.3v. Typically a 2.2K resistor is used on Teensy devices.

    Teensy sells 320x240 displays in their store, and provides a fast driver for it:

  3. #3
    Senior Member
    Join Date
    Apr 2013
    Posts
    1,879
    Also depending a bit on the display most character LEDs can run on 3.3V for the controller. Key thing is that contrast and LED normally need to be 5V. So if you have access to a 2*16 LCD and want to muck around with it a bit you can probably get a mixture of 3.3V and 5V that works. Does depend on having logic and LED+contrast as separate supplies on the header. Not best practice for a commercial product unless you have control of the supply chain but if this is for your use and character LCD readability, size and contrast is a best fit go for the thing that is mass produced and cheap.

  4. #4
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    20,171
    Most of all of the 5V character LCDs have TTL level logic thresholds, where anything over 2.0V is recognized as logic high. So they tend to work with 3.3V only logic, as long as all the signals are from the Teensy to the LCD.

    The LiquidCrystal library has 4 different constructors, for using 6, 7, 10 and 11 signals. Use the 6 signal option, where you connect the R/W signal on the LCD to GND. This mode uses 6 outputs from the Teensy to control the LCD. The LCD never tries to drive 5 volts onto the data pins, because R/W is always low.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •