This guide just covers Ordnance Survey Grid Reference conversion - we'll cover UTM, MGRS and USNG in a separate guide as they do work a little differently and those three work in a bit more of a roundabout fashion than the Ordnance Survey Grid Reference way.  Although this guide shows Ordnance Survey (Great Britain) grid references, the methodology behind it applies equally to the Ordnance Surven (Ireland) grid references. 

There are two ways to convert between Latitude/Longitude and Ordnance Survey Grid Reference coordinates using NavigX Touch - using the pickers and the map.

You'll need to use the picker method first, as the map needs to know where to start generating from in order to prevent a lot of finger scrolling and zooming. 

When you select the 'Convert' tab on the tab bar at the bottom of the screen, you're presented with three blank boxes.  Touching any one of them will generate a picker.

If you've touched either the Latitude or Longitude cell, you'll have to enter both coordinates to generate your grid reference.  If you touched on the OS Grid cell, you'll just need to enter that to generate your Latitude and Longitude coordinates.

Once you've generated your coordinates, you should see that the 'Map' button appears at the top left corner.

At the right of the navigation bar is a '+' button.  If you touch this, you'll be able to add the converted point to the Waypoint database.  We'll not cover the waypoint database in this guide as it has its own guide. 

Pressing the 'Map' button should see a map slide into view from the bottom of the screen.  This map is centered on the coordinate that you entered on the first conversion screen.

You should see that the grid reference you entered or generated is at the top of the screen and there's a crosshair in the centre of the screen where your grid reference is.

If you're familiar with the iPhone's Maps application, then this view should appear familiar to you. You can use touch gestures on the map in the same way, too. Pinching zooms in or out and moving your finger around on the map scrolls the map around, too.

The crosshairs are fixed in the centre of the map and the grid reference at the top of the map always displays the grid reference of the point on the map under the crosshair.

You'll notice that on both screens, you've got a '+' icon at the right of the navigation bar.  This button allows you to add the point on the map to the waypoint database.

Please note that when you add the point under the map to the database, it isn't the grid reference that is stored.  The point is stored as a Latitude/Longitude coordinate so you'll always get the right point, rather than the origin of the grid square (which is the bottom-left corner of the grid square).

Once you're done with the map view, clicking the 'Back' button will take you back to the original conversion display.  The centre point of the map is taken back to the original display and shown in both Latitude/Longitude format and Ordnance Survey Grid Reference format.

And that's about it for the conversion displays. We've looked at the basics of performing a conversion as well as deriving conversions from the map view.  We've also looked at how to manipulate the map to get the information that you require. If you need any further information, please don't hesitate to let us know.