From d87d2a2e07ebb7e918198b89eb875d55817b006e Mon Sep 17 00:00:00 2001
From: erikkaashoek <erik@kaashoek.com>
Date: Wed, 13 Jan 2021 16:46:12 +0100
Subject: [PATCH] Display test added

---
 nanovna.h |  1 +
 plot.c    | 21 +++++++++++++++++++++
 sa_core.c |  9 +++++++++
 3 files changed, 31 insertions(+)

diff --git a/nanovna.h b/nanovna.h
index c40478f..be5f0ee 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -540,6 +540,7 @@ float get_trace_scale(int t);
 float get_trace_refpos(int t);
 const char *get_trace_typename(int t);
 extern int in_selftest;
+extern int display_test(void);
 
 //
 // Shell config functions and macros
diff --git a/plot.c b/plot.c
index fd4b73d..b466329 100644
--- a/plot.c
+++ b/plot.c
@@ -2386,6 +2386,27 @@ redraw_frame(void)
   draw_cal_status();
 }
 
+int display_test(void)
+{
+//  return true;
+  // write and read display, return false on fail.
+  for (int h = 0; h < LCD_HEIGHT; h++) {
+      for (int w = 0; w < LCD_WIDTH; w++) {
+        spi_buffer[w] =  ((w*h) & 0xfff);
+      }
+      ili9341_bulk(0, h, LCD_WIDTH, 1);
+      for (int w = 0; w < LCD_WIDTH; w++) {
+        spi_buffer[w] = 0;
+      }
+      ili9341_read_memory(0, h, LCD_WIDTH, 1, LCD_WIDTH, spi_buffer);
+      for (int volatile w = 0; w < LCD_WIDTH; w++) {
+        if (spi_buffer[w] != ((w*h) & 0xfff))
+          return false;
+      }
+  }
+  return true;
+}
+
 //#define _USE_WATERFALL_PALETTE
 #ifdef  _USE_WATERFALL_PALETTE
 #include "waterfall.c"
diff --git a/sa_core.c b/sa_core.c
index e9bb41d..c45401e 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -3219,6 +3219,15 @@ void self_test(int test)
     if (setting.test_argument > 0)
       test_step=setting.test_argument-1;
     do {
+      if (test_step == 0) {
+        if (!display_test()) {
+          test_step = TEST_END;
+          show_test_info = FALSE;
+          ili9341_set_foreground(LCD_BRIGHT_COLOR_RED);
+          ili9341_drawstring_7x13("Display read fails", 30, 140);
+          goto resume2;
+        }
+      }
       test_prepare(test_step);
       test_acquire(test_step);                        // Acquire test
       test_status[test_step] = test_validate(test_step);                       // Validate test