Add Contrast feature

ui/menu.c

@@ -129,6 +129,7 @@ const t_menu_item MenuList[] =
 	{"SetLow", VOICE_ID_INVALID,                       MENU_SET_LOW       },
 	{"SetPtt", VOICE_ID_INVALID,                       MENU_SET_PTT       },
 	{"SetTot", VOICE_ID_INVALID,                       MENU_SET_TOT       },
+	{"SetCtr", VOICE_ID_INVALID,                       MENU_SET_CTR       },
 #endif
 	// hidden menu items from here on
 	// enabled if pressing both the PTT and upper side button at power-on
@@ -899,6 +900,12 @@ void UI_DisplayMenu(void)
 		case MENU_SET_TOT:
 			strcpy(String, gSubMenu_SET_TOT[gSubMenuSelection]);
 			break;
+
+		case MENU_SET_CTR:
+			sprintf(String, "%d", gSubMenuSelection);
+			gSetting_set_ctr = gSubMenuSelection;
+			ST7565_Contrast();
+			break;
 #endif
 
 	}