From d9106c6951e63a2b6a4a884e5f91a5feca7af51d Mon Sep 17 00:00:00 2001
From: Adam Wonak <adam.wonak@gmail.com>
Date: Sun, 8 Jun 2025 11:39:12 -0700
Subject: [PATCH] refactor calibrate analog demo to use tge u8g2 library.

---
 .../calibrate_analog/calibrate_analog.ino     | 63 ++++++++++++-------
 1 file changed, 40 insertions(+), 23 deletions(-)

diff --git a/examples/calibrate_analog/calibrate_analog.ino b/examples/calibrate_analog/calibrate_analog.ino
index 4dc1e2a..c3e6a5f 100644
--- a/examples/calibrate_analog/calibrate_analog.ino
+++ b/examples/calibrate_analog/calibrate_analog.ino
@@ -19,6 +19,10 @@
 
 #include "gravity.h"
 
+#define TEXT_FONT u8g2_font_profont11_tf
+#define INDICATOR_FONT u8g2_font_open_iconic_arrow_1x_t
+#define U8G2_UP_ARROW_GLYPH 0x43 // caret-up '˄'
+
 byte selected_param = 0;
 
 // Initialize the gravity library and attach your handlers in the setup method.
@@ -46,7 +50,7 @@ void CalibrateCV(Direction dir, int val) {
             cv->AdjustCalibrationLow(val);
             break;
         case 1:
-            cv->AdjustCalibrationOffset(val);
+            cv->SetOffset(val);
             break;
         case 2:
             cv->AdjustCalibrationHigh(val);
@@ -55,51 +59,64 @@ void CalibrateCV(Direction dir, int val) {
 }
 
 void UpdateDisplay() {
-    gravity.display.clearDisplay();
-    DisplayCalibration(&gravity.cv1, "CV1: ", 0);
-    DisplayCalibration(&gravity.cv2, "CV2: ", 1);
-    gravity.display.display();
+    gravity.display.firstPage();
+    do {
+        // Set default font mode and color for each page draw
+        gravity.display.setFontMode(0); // Transparent font background
+        gravity.display.setDrawColor(1); // Draw with color 1 (ON)
+        gravity.display.setFont(TEXT_FONT);
+        DisplayCalibration(&gravity.cv1, "CV1: ", 0);
+        DisplayCalibration(&gravity.cv2, "CV2: ", 1);
+    } while (gravity.display.nextPage());
+
 }
 
-void DisplayCalibration(AnalogInput* cv, String title, int index) {
+void DisplayCalibration(AnalogInput* cv, const char* title, int index) {
+    
     int barWidth = 100;
     int barHeight = 10;
     int textHeight = 10;
     int half = barWidth / 2;
     int offsetX = 16;
     int offsetY = (32 * index);
-    int color = 1;
+
+    // U8g2 draw color: 1 for foreground (white/on), 0 for background (black/off)
+    gravity.display.setDrawColor(1);
 
     // CV value reading.
-    int value = constrain(cv->Read(), -512, 512);
+    int value = cv->Read();
 
-    gravity.display.setCursor(0, offsetY);
+    // Set cursor and print title and value
+    gravity.display.setCursor(0, offsetY + textHeight); // Adjust y-position to align with text base line
     gravity.display.print(title);
-    gravity.display.print(value >= 0 ? " " : "");
+    if (value >= 0) gravity.display.print(" "); // Add space for positive values for alignment
     gravity.display.print(value);
 
-    gravity.display.setCursor(92, offsetY);
-    gravity.display.print(value >= 0 ? " " : "");
-    gravity.display.print(cv->Voltage());
+    // Print voltage
+    gravity.display.setCursor(92, offsetY + textHeight); // Adjust x,y position
+    if (cv->Voltage() >= 0) gravity.display.print(" ");
+    gravity.display.print(cv->Voltage(), 1); // Print float with 1 decimal place
     gravity.display.print(F("V"));
 
-    gravity.display.drawRect(offsetX, textHeight + offsetY, barWidth, barHeight, color);
+    // Draw the main bar rectangle
+    gravity.display.drawFrame(offsetX, textHeight + offsetY + 2, barWidth, barHeight); // Using drawFrame instead of drawRect
+
     if (value > 0) {
         // 0 to 512
-        int x = (float(value) / 512.0) * half;
-        int fill = min(x, 512);
-        gravity.display.fillRect(half + offsetX, textHeight + offsetY, fill, barHeight, color);
+        int x = map(value, 0, 512, 0, half); // Map value to bar fill width
+        gravity.display.drawBox(half + offsetX, textHeight + offsetY + 2, x, barHeight); // Using drawBox instead of fillRect
     } else {
         // -512 to 0
-        int x = (float(abs(value)) / 512.0) * half;
-        int fill = min(half, x);
-        gravity.display.fillRect((half + offsetX) - x, textHeight + offsetY, fill, barHeight, color);
+        int x = map(abs(value), 0, 512, 0, half); // Map absolute value to bar fill width
+        gravity.display.drawBox((half + offsetX) - x, textHeight + offsetY + 2, x, barHeight); // Using drawBox
     }
 
     // Display selected calibration point if selected calibration point belongs to current cv input.
     if (selected_param / 3 == index) {
-        int left = offsetX + ((half - 2) * (selected_param % 3));
-        int top = barHeight + textHeight + offsetY + 2;
-        gravity.display.drawChar(left, top, 0x1E, 1, 0, 1);
+        int charWidth = 6;
+        int left = offsetX + (half * (selected_param % 3) - 2); // Adjust position
+        int top = barHeight + textHeight + offsetY + 12;
+        // Drawing an arrow character (ASCII 0x1E is often an up arrow in some fonts, might need adjustment)
+        gravity.display.drawStr(left, top, "^"); // Draw the arrow character
     }
 }