Here are the I2C devices
UU is the reading of when only the DigiOne is connected.
The 27 is the LCD display.
I can confirm that the SDA & SCL positions are correct.
I tried adjusting the contrast controls (and it adjusts contrast) but nothing else. This is the default look of the display
When I run: sudo systemctl restart pydpiper.service I get no errors nor confirmation of success. Just a clear terminal.
look for the error. misspelled driver parameters or pages file.
A systemctl services file has been provided with examples for several different popular configurations. You will need to enable the appropriate ExecStart line for your particular configuration. You do this by removing the ‘#’ character at the start of the line for the ExecStart that is appropriate. It is possible that you will also need to edit some of the values for the ExecStart command if your configuration is different than what was provided.
IMPORTANT: There must be one and only one ExecStart enabled within the file.
The general format for the ExecStart lines is as follows:
ExecStart=/usr/bin/docker run --network=host --privileged -v /var/log:/var/log:rw dhrone/pydpiper:latest python /app/pydPiper.py --<musicdistro> --driver <driver> --width <width> --height <height> --i2caddress <i2caddress> --i2cport <i2cport> --rs <rs> --e <e> --d4 <d4> --d5 <d5> --d6 <d6> --d7 <d7> --timezone <timezone> --temperature <temperature> --lmsplayer <lmsplayer> --pages <pagefile>
Definitions for command line Parameters
<driver> – Driver for your display. Possible values are ‘winstar_weg’, ‘hd44780’, ‘hd44780_i2c’, ‘ssd1306_i2c’
<musicdistro> – Sets the type of music player pydPiper is installed on. Possible values are ‘volumio’, ‘rune’, ‘lms’
<width> – width of your display in pixels. If you are using a character display, each column is 5 pixels wide <height> – height of your display in pixels. If you are using a character display, each line is 8 pixels high
For I2C displays <i2caddress> – The I2C address your display is installed on. Normally 0x27. <i2cport> – The I2C port your display is attached to. Normally 1.
This is what I entered into the prompts triggered by:
sudo ./install_volumio.sh
For the last command:
sudo systemctl restart pydpiper.service
Should it be pydpiper.service or pydpiper.volumio.service being passed into the above command?
pydpiper. service.
everything is correct for you and should work. further I am powerless. examine the log file of the program.
https://community.volumio.com/search?context=topic&context_id=12383&q=Pydpiper&skip_context=true
SUCCESS!
I did a fresh flash of the latest version of buster and re-installed using the install guide on https://github.com/dhrone/pydPiper
Thank you so much for helping me work thru this 
I have to see about tweaking the formatting (note the un-used line)
but so excited to have it working now.
Do you have to do anything special to implement the display changes?
I stripped down
pages_lcd_20x4.py
to the bar bones display setting on the pydPiper github like this:
but my screen is still stuck looking like this:
my example file in the post above.
to edit the file, you have to figure it out yourself. it will take time and patience.
restart the service after each change.
I ask for help for a 20x4 LCD modules.
I can’t get the display to work 
does anyone have a tip for me ?
Raspberry 3b+, Volumio 3x
https://www.amazon.com/SunFounder-Serial-Module-Arduino-Mega2560/dp/B01GPUMP9C?th=1
To begin with, you need to get the following result. Two stripes on the screen. https://community.volumio.com/uploads/default/original/2X/3/35dc2477c644686f11376b6716709da158e416a3.jpeg
Didn’t you turn the blue potentiometer on I2C-board?
Maybe this will get you going:
Yes 
unfortunately without change
I am desperate, could someone offer the pydpiper directory for download ?
Try a clean Volumio installation and then PydPiper.
