In some cases it is difficult or impossible to touch on screen elements at the edges of a touch screen.

Edge adjust (previously referred to as Edge Acceleration) is a feature to deal with such cases. It works by "learning" where the touchable extremities lie and treating this as the input edge.

UPDD uses a setting, edge_adjust_margin, that defines the size in % of a margin around the controlled on screen area (monitor or segment) used by the edge adjust feature. By default this setting is set to 2. This can be adjusted as required in the UPDD Console:

Any touch that falls within edge_adjust_margin % of any edge of a touchable area (monitor, desktop or segment) will be adjusted towards the real edge.

The degree of adjustment takes account of the outer bounding rectangle of previous touches since the last calibration.

In normal use this makes it possible for a user to touch on screen elements at the edges.

Until an extreme edge has been touched there will be a degree of inaccuracy, this reduces the closer to the edge that the user touches and becomes zero in that case that the edge can be and is touched.

This feature can be disabled by setting the Edge acceleration margin to 0.

You can also use the command line interface command to set the setting i.e. 'upddutils set edge_adjust_margin 0' to set for updd device 1