From b0901daa85d95a4020056a030c6aecb02df22d1e Mon Sep 17 00:00:00 2001
From: Iakabos <46475652+Iakabos@users.noreply.github.com>
Date: Sun, 19 Jul 2020 17:18:08 -0700
Subject: [PATCH] display: Add configuration options for OLED displays (#3084)

Add user-configurable contrast, vcomh (affects "smearing"), and invert options for SSD1306/SH1106 type OLED displays.

Signed-off-by:  James Esau <james_esau@hotmail.com>
---
 config/example-extras.cfg       | 12 ++++++++++--
 klippy/extras/display/uc1701.py |  9 ++++++---
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/config/example-extras.cfg b/config/example-extras.cfg
index 6ab4398b..f5f6bdb4 100644
--- a/config/example-extras.cfg
+++ b/config/example-extras.cfg
@@ -1831,8 +1831,16 @@
 #   optional. The cs_pin and a0_pin parameters must be provided when
 #   using an uc1701 display.
 #contrast: 40
-#   The contrast to set when using a uc1701 type display.  The value may
-#   range from 0 to 63.  Default is 40.
+#   The contrast to set when using a uc1701 or SSD1306/SH1106 type display
+#   For UC1701 the value may range from 0 to 63.  Default is 40.
+#   For SSD1306/SH1106 the value may range from 0 to 256.  Default is 239.
+#vcomh: 0
+#   Set the Vcomh value on SSD1306/SH1106 displays. This value is
+#   associated with a "smearing" effect on some OLED displays.
+#   The value may range from 0 to 63. Default is 0.
+#invert: FALSE
+#   TRUE inverts the pixels on certain OLED (SSD1306/SH1106) displays
+#   The default is FALSE
 #cs_pin:
 #dc_pin:
 #spi_bus:
diff --git a/klippy/extras/display/uc1701.py b/klippy/extras/display/uc1701.py
index bcca8a5e..1c491dd3 100644
--- a/klippy/extras/display/uc1701.py
+++ b/klippy/extras/display/uc1701.py
@@ -202,6 +202,9 @@ class SSD1306(DisplayBase):
             io_bus = io.spi
         self.reset = ResetHelper(config.get("reset_pin", None), io_bus)
         DisplayBase.__init__(self, io, columns)
+        self.contrast = config.getint('contrast', 239, minval=0, maxval=255)
+        self.vcomh = config.getint('vcomh', 0, minval=0, maxval=63)
+        self.invert = config.getboolean('invert', False)
     def init(self):
         self.reset.init()
         init_cmds = [
@@ -215,12 +218,12 @@ class SSD1306(DisplayBase):
             0xA1,       # Set Segment re-map
             0xC8,       # Set COM output scan direction
             0xDA, 0x12, # Set COM pins hardware configuration
-            0x81, 0xEF, # Set contrast control
+            0x81, self.contrast, # Set contrast control
             0xD9, 0xA1, # Set pre-charge period
-            0xDB, 0x00, # Set VCOMH deselect level
+            0xDB, self.vcomh, # Set VCOMH deselect level
             0x2E,       # Deactivate scroll
             0xA4,       # Output ram to display
-            0xA6,       # Normal display
+            0xA7 if self.invert else 0xA6, # Set normal/invert
             0xAF,       # Display on
         ]
         self.send(init_cmds)