From 1625019b7a82c467735b91872717bf6699643eee Mon Sep 17 00:00:00 2001
From: Carsten Schmiemann <carsten.schmiemann@pfalz-mail.de>
Date: Sun, 20 Nov 2022 01:09:02 +0100
Subject: [PATCH] Add graph autoscale

---
 src/display.cpp | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/display.cpp b/src/display.cpp
index 33ff4d4..4afe00a 100644
--- a/src/display.cpp
+++ b/src/display.cpp
@@ -253,8 +253,6 @@ void display_screen_graph(float values[100], char* key, int buffersize)
             display_header(title_graph);
             display.drawLine(7, 60, 9, 60); //X mark
             display.drawLine(9, 8, 9, 62); //Y boarder
-            display.drawStr(1,17, "1");
-            display.drawStr(1,40, "5");
             display.drawStr(1,63, "0");
             display.drawLine(7, 36, 9, 36); //marker Y 5
             display.drawLine(7, 13, 9, 13); //marker Y 1
@@ -264,11 +262,39 @@ void display_screen_graph(float values[100], char* key, int buffersize)
                 display.drawLine(i, 60, i, 62); //marker X
             }
 
-            //Data display
+            // Auto-scale graph (scale 1kW to 15kW automatically)
+            float max = values[0];
+            // find highest value
             for (int i = 0; i<buffersize; i++)
             {
-                display.drawLine((10+i), 60, (10+i), map(values[i], 0, 1000, 60, 10));
+                if (max < values[i])
+                {
+                    max = values[i];
+                }
             }
+            int graph_max_kW = 1000;
+            if (max > 2000) { graph_max_kW = 2000; }
+            else if (max > 3000) { graph_max_kW = 3000; }
+            else if (max > 4000) { graph_max_kW = 4000; }
+            else if (max > 4000) { graph_max_kW = 4000; }
+            else if (max > 5000) { graph_max_kW = 5000; }
+            else if (max > 6000) { graph_max_kW = 6000; }
+            else if (max > 7000) { graph_max_kW = 7000; }
+            else if (max > 8000) { graph_max_kW = 8000; }
+            else if (max > 9000) { graph_max_kW = 9000; }
+            else if (max > 10000) { graph_max_kW = 10000; }
+            else if (max > 11000) { graph_max_kW = 11000; }
+            else if (max > 12000) { graph_max_kW = 12000; }
+            else if (max > 13000) { graph_max_kW = 13000; }
+            else if (max > 14000) { graph_max_kW = 14000; }
+            else if (max > 15000) { graph_max_kW = 15000; }
+            else if (max > 16000) { graph_max_kW = 16000; }
+            display.drawStr(1,17, (char*)(graph_max_kW/1000));
 
+            for (int i = 0; i<buffersize; i++)
+            {
+                display.drawLine((10+i), 60, (10+i), map(values[i], 0, graph_max_kW, 60, 10));
+            }
+            display.drawStr(120, 10, key);
         } while ( display.nextPage() );
 }
\ No newline at end of file