LCD Screen Problem

Hi I am building a sampler box and I am very excited about it.

It's awesome and thank you for everyone involved into it.

the first build I did works fine either with USB audio and with HDMI Audio so all good from this point of view.
I also added buttons which work fine to change presets

Now I am trying to add a screen LCD and I got the HD44780 1602 and soldered by this by the standard of http://www.nickyspride.nl/sb2/ (see picture below)

Then I noticed that http://homspace.xs4all.nl/homspace/samplerbox/ has a different connection scheme for the LCD

So question number

1) what is the "Samplerbox Standard" for connecting the LCD 16x2 to the GPIO?

I downloaded and "baked" the image "2017-05-17_samplerbox.img.zip" from the this site (samplerbox.org) and booted on my raspberry pi Zero and everything works except the Screen which turns on and shows all squares on the bottom line only.

I configured the file config.ini on the root with the following

MAX_POLYPHONY = 40
MIDI_CHANNEL = 1
SAMPLERATE = 44100
GLOBAL_VOLUME = 100
USE_FREEVERB = False
USE_I2C_7SEGMENTDISPLAY = False
USE_SERIALPORT_MIDI = False
USE_TONECONTROL = False
USE_HD44780_16X2_LCD = True
USE_HD44780_20X4_LCD = False
USE_BUTTONS = True
USE_GUI = False
SAMPLES_DIR = None
AUDIO_DEVICE_ID = 2 (for my USB keyboard/audio interface)
AUDIO_DEVICE_NAME = autodetect
BOXRELEASE = 30
PRESET_BASE = 0
SYSTEM_MODE = 1 (I tried 2 as well)
RAM_LIMIT_PERCENTAGE = 40
INVERT_SUSTAIN = False

PRINT_MIDI_MESSAGES = True
PRINT_LCD_MESSAGES = True

GPIO_LCD_RS = 7
GPIO_LCD_E = 8
GPIO_LCD_D7 = 18 (configured this in accordance to mine)
GPIO_LCD_D6 = 23 (configured this in accordance to mine)
GPIO_LCD_D5 = 24 (configured this in accordance to mine)
GPIO_LCD_D4 = 25 (configured this in accordance to mine)

BUTTON_LEFT_MIDI = 176, 48, <MIDI CONTROLLER NAME>
BUTTON_RIGHT_MIDI = 176, 50, <MIDI CONTROLLER NAME>
BUTTON_ENTER_MIDI = 176, 49, <MIDI CONTROLLER NAME>
BUTTON_CANCEL_MIDI = 176, 65, <MIDI CONTROLLER NAME>

BUTTON_LEFT_GPIO = 26
BUTTON_RIGHT_GPIO = 13
BUTTON_ENTER_GPIO = 6
BUTTON_CANCEL_GPIO = 12

I tired both system mode 1 and 2 and nothing on the screen.

I can adjust the potentiometer for the contrast and if I go full only squares appears otherwise nothing at all.

What am I doing wrong? Please can anyone help? Thank you so much in advance and thank you for this awesome work!!

Hi Ayskura,
2x16 displays are all in independent forks.
Erik used mine = the "homspace one", but after he did I changed the connections of the data lines (so the four solid green lines, the dotted ones are for enabling 8-bit mode).
In Eriks drawing the data lines are brown.

It seems you mixed up the various versions.
You downloaded the official version, which only supports a 3 character display.
The configuration parameters you mention belong to Alex's version which incorporates enhancements of Erik and me.
In Alex's version the connections are different again, but you already adapted config to your soldering.

So I suggest you switch to Alex's version, not only because you made it match your soldering now, but it's also the most user friendly one (for mine you need programming skills and Erik stopped a year ago).
But whatever you do: use the connections belonging to the script you use; the forks are NOT compatible.

Ok thank you HandEhv

I actualy mde a another one work with I2C connection on the back of the 16x2...

I thought they were interchangeable :) thank you