add micro and pi

Font5x7.c

@@ -549,38 +549,38 @@ const uint16_t x5x7_bits [] =
      +----------------+
      |                |
      |                |
-     | ***            |
-     | * *            |
+     |*****           |
      | * *            |
      | * *            |
+     |*  **           |
      |                |
      +----------------+ */
   0x0000,
   0x0000,
-  0x7000,
-  0x5000,
+  0xf800,
   0x5000,
   0x5000,
+  0x9800,
   0x0000,
 
   /* Character (0x1d):
      bbw=5, bbh=7, bbx=0, bby=-1, width=5
      +----------------+
      |                |
-     |   *            |
-     | ***            |
-     |  *             |
+     |                |
+     |*  *            |
+     |*  *            |
+     |*  *            |
      |***             |
      |*               |
-     |                |
      +----------------+ */
   0x0000,
-  0x1000,
-  0x7000,
-  0x2000,
-  0x7000,
-  0x4000,
   0x0000,
+  0x9000,
+  0x9000,
+  0x9000,
+  0xe000,
+  0x8000,
 
   /* Character (0x1e):
      bbw=5, bbh=7, bbx=0, bby=-1, width=5

nanovna.h

@@ -122,6 +122,8 @@ void draw_cell_all(void);
 extern const uint16_t x5x7_bits [];
 extern const uint32_t numfont20x24[][24];
 
+#define CHAR_PI    '\0x1c'
+#define CHAR_MICRO '\0x1d'
 #define CHAR_OHM   '\0x1e'
 
 int caldata_save(void);