Help Requested: Python Setup 763-NHD-0420CW-AW3

kilian579

• February 22, 2019 08:07

Good Morning,

I have purchased a 763-NHD-0420CW-AW3 NewHaven Character Dipslay and I'm currently trying to get it to run.
To send data to the display, I'm using a Raspberry Pi 3 and simple python scripts.
I have used some other Newhaven character display before this one.

The problem is that I'm unable to figure out if i connected the Pins correctly, since the screen displays nothing, when I run the test script.

The Script is asking for this:
 __init__(self, dc, clk, cs, d0, d1, d2, d3, d4, d5, d6, d7, reset):

And I've tried the display pins that sounded most alike (display manual) to GPIO pins and hand them over:
lcd=NhdLcd(2,3,18,26,19,13,6,4,17,27,22,10)

Got my test script from here:
https://github.com/wjskrydl/nhd-oled


Power etc should also be connected correctly.
Is there something special, that I need to keep in mind with this specific display?
Is my Pin layout correct?

0

• 

  Ted M.

  NHD Staff

  • February 22, 2019 09:07

  Please check pins 17-19 for BS0 to BS2 on the display.  For an 8-bit parallel interface, pin 17 is tied low, pins 18 and 19 are tied high.
  
  Best Regards,

  0
• 

  garbage98

  • February 27, 2019 09:07

  SOLVED
  We tried connecting the Display using the user manual (https://www.mouser.de/datasheet/2/291/NHD-0420CW-AW3-1266321.pdf)
  
  This is our working setup:

  

  A few necessary additions in our code:

          self.__b0=16
          self.__b1=20
          self.__b2=21
  
          #B
          GPIO.setup(self.__b0, GPIO.OUT)
          GPIO.setup(self.__b1, GPIO.OUT)
          GPIO.setup(self.__b2, GPIO.OUT)
          GPIO.output(self.__b0, GPIO.LOW)
          GPIO.output(self.__b1, GPIO.HIGH)
          GPIO.output(self.__b2, GPIO.HIGH)

  thank you!

  0
• 

  garbage98

  • February 27, 2019 11:07

  pin 17 is tied low, pins 18 and 19 are tied high.

  What does tie high and tie low mean exactly? How do I need to connect them?
  -> Send GPIO.High/GPIO.LOW by default
  
  
  Further questions:
  Should I rather use 2.8V or 5V mode?
  
  EDIT:
  Thank you i figured it out and managed to display text.

  0
• 

  Ted M.

  NHD Staff

  • February 27, 2019 15:07

  Thanks for posting the update.  Nice to see you have it working! 
  
  Best Regards,

  0

Please sign in to leave a comment.