The DryFire Universal Trigger Unit

The DryFire Universal Trigger unit attaches to your own firearm.

The trigger unit consists of the following parts:

A – Release mode jumper
B – Status indicator LED
C – Trigger switch connector
D – IR laser

E – Power switch

Release mode jumper

By default, the trigger unit will fire when the trigger switch is pressed. Insert a jumper across the release mode header to make the unit fire when the trigger switch is released.

Status indicator LED

The LED lights up when the unit is powered up and when a shot is fired.

Trigger switch connector

Wrap the trigger switch around the trigger on your firearm and plug the cable into the connector on the trigger as shown in the diagram.

IR laser

SAFETY INFORMATION: Even though the laser flashes at low power for a fraction of a second, make sure you do not look directly into the laser or point it into the face of another person.


The trigger unit contains a bluetooth chip, which allows it to be configured from a computer (running with BLE connectivity on Windows 10) or from a suitable iOS device. An app to configure the trigger unit will be available soon.

Changing batteries

The trigger unit takes 4 LR44 (1.5V) batteries. The unit unscrews at the power switch end:

Insert new batteries with the positive terminal towards the switch.

Configuring the trigger Unit from Windows 10

System requirements

The DryFire Trigger Configuration tools for Windows requires a PC running Windows 10 (OS version 1703) that has Bluetooth Low Energy (BLE) connectivity. It is best to update to the latest version of Windows 10.


The configuration tools is a separate installer to DryFire V4.

  1. Download DryFireTriggerConfig from the DryFire website.
  2. Double click on TriggerApp.appxbundle to run the installer

Configuring the trigger Unit from an iPhone or iPad

System requirements

The iPhone or iPad must be running iOS 8.0 or later.


The configuration tool for iOS is available as a free app on the Apple App Store.

  1. Download and install DryFire Trigger Unit App

Configuring the trigger unit

When the configuration program is launched, it connects to the trigger unit and reads settings. The trigger unit must be advertising before it can connect. When the unit is first switched on, it advertises for about a minute. Alternatively, you can hold down the trigger switch for 5 seconds to start advertising; the LED will stay on for a second and then you can release the trigger switch.

The trigger unit shows it is advertising by flashing its LED every 2 seconds.

When the settings have been read, they are displayed as follows:

Trigger Unit Settings

Firing settings

The trigger unit has three firing modes. Fire on press fires the laser when the trigger switch is pressed. Fire on release fires the laser when the trigger switch is released. Universal mode fire the laser based on detecting vibrations consistent with the actual trigger being pressed.

Note that setting the firing mode here, will override the state of the release mode jumper.

Laser settings

The laser pulse length is the number of milliseconds for which the laser is active when it is fired. This must be a multiple of 10. A value of 40 milliseconds should be sufficient.

Universal settings

The trigger sensitivity is a value that reflects how much jerkiness in the movement of the sensor causes the unit to fire. The Weight X, Y and Z values (in advanced settings) determine how much movement along the respective axes influence the trigger sensitivity.