Processor Units Perun

A processor unit is an advanced electronic system that replaces classic trigger contacts and their mechanical parts. The main brain of the processor is a microprocessor that electronically controls the trigger, fire selector, cycle detection, battery measurement, resistance, and much more.
Compared to a classic MOSFET, the processor contains an active brake and programmable functions. These units allow us to fine-tune our weapons according to our needs and the components used. 
Essentially, each processor unit is unique. Individual manufacturers customize processor units according to their own preferences, whether it be individual settings, programming methods, sensor types, or other technical details, but at the same time, they try to use the same functions and dimensions as other manufacturers for user convenience. Today's units are manufactured as drop-in modules that are inserted directly into the gearbox, so only two cables with connectors lead to the stock.

What weapons are processor units manufactured for?

Processor units are most often manufactured for V2 and V3 gearboxes (M4, Ak, RPK, MP5, etc.). Some manufacturers, such as Perun Airsoft, also manufacture processor units for special weapons. These include processor units for the P90/AUG and Kriss Vector. Unfortunately, processor units are not manufactured for machine guns due to the design of the gearbox and their full auto function, with the exception of, for example, the RPK, which has a V3 gearbox. However, this was once also claimed about the P90 or CZ Evo... 

Advantages of the processor unit

• Longer weapon life
• Faster trigger response 
• Option to set firing modes
• Battery discharge level monitoring 
• Weapon diagnostics and smart safety features
• Special modes (DSG, MDR)
• Special magazine modes
• Imitation of live weapon triggers – Installation of Clickers
• Connecting the weapon to a phone
• Etc.

Processor units also solve the problem of double shots in semi-automatic mode, because when installing the processor unit, we remove the interrupt lever. At the same time, thanks to the replacement of classic switching contacts, we have precise trigger operation that is always the same and can be set exactly according to our requirements.

Imitation of real firearm triggers 

Today's processor units, in an effort to achieve the highest degree of realism, offer various accessories that imitate the trigger action of real weapons. For example, Perun airsoft also has this accessory, called the Clicker. This small accessory is designed for realism lovers who want to have a tactile feeling on the trigger. The Clicker is an accessory designed for use with the Perun V2 / V3 Hybrid device. It introduces a pause in the trigger action that must be overcome in order to fire a shot, which is somewhat similar to how the trigger works in a real firearm. The weight (resistance) of the trigger is adjustable.

Our tip:
There are several versions of Perun clickers (imitation live triggers). Clicker, Clicker PRO, and Speeder Clicker.
- Clicker was the first version of the imitation live trigger from Perun airsoft.
- Clicker PRO was released in 2025 and is designed for maximum realism, higher trigger stiffness, and the ability to secure the replica. 
- Speeder Clicker is designed for fast weapons for CQB, Speedsoft, and the like, speeds up trigger reset, and does not have as much resistance. 

How does detection work in processor units?

In order for the processor unit to correctly detect wheel cycles, switch movements, and, if applicable, breaker lever movements, a suitable detection mechanism must be used. The most commonly used are microswitches, optical sensors, and detection using magnets/Hall probes.

• Microswitches were the first method used to detect the cycles of important parts. The disadvantage is possible mechanical damage or wear of the switch levers. Fortunately, they are easy to replace if damaged. Microswitches have gradually been replaced by more modern optical sensors.

• Magnets are another method of sensing. They are installed on the trigger, switch gate, and piston wheel. The advantage is their virtually infinite durability. When installing magnets, we must ensure that they are positioned as accurately as possible and then glued as securely as possible (otherwise there is a risk of them coming loose and damaging the internal parts of the gearbox).
• Optical sensors are the most popular option today. Thanks to optical sensing, there is no need to glue magnets, and thanks to the absence of mechanical elements, there is no wear and tear. 

• The Hall probe is another commonly used sensor that utilizes the Hall effect, whereby a current flows through a semiconductor plate and, thanks to a perpendicular magnetic field, the charge in the plate is rearranged to one side, creating a measurable voltage at its edges (sides). This voltage is proportional to the strength of the magnetic field. 

Modern processor units can have a combination of several types of sensors. For example, Perun Hybrid uses a hall probe after the trigger and optical sensors to detect the wheel cycle and switch gate.

How are processor units actually programmed?

Processor units are programmed in various ways, namely via the trigger and firing switch, via a special programming module, or via a smartphone app using Bluetooth. We may also encounter programming via multiple options. 

    Programming via the trigger and firing switch 

In this mode, we then move by pressing the trigger and switching between SEMI and AUTO. To facilitate orientation, manufacturers supply programming tables together with the processor units, which indicate how many times we need to press the trigger or where to switch the switch to get to our selected option. In earlier processor units, this setting was done by activating the programming mode immediately after connecting the battery, for example by pressing and holding the trigger. The rest of the procedure was identical to today's versions.

Advantages: Programming speed, no mobile phone required, immediate response (vibration)
Disadvantages: More complicated programming, no possibility to update the processor firmware

Our tip:
Processor units that are programmed via a switch and shutter release are usually very intuitive and programming can be quickly understood – so don't be afraid of them! If necessary, you can find video tutorials on programming all the processor units we sell on our YouTube channel. 

 Programming applications

These applications are a very convenient and quick way to set up a processor unit. Just download the application to your phone, then connect your phone to the processor unit via cable or Bluetooth, and you can start setting it up. Another big advantage is the ability to quickly update the processor's firmware. 

Advantages: Convenience, speed, ability to upgrade firmware
Disadvantages: Possible signal quality issues between the processor unit and the phone, need to have the app installed, during battle the weapon must be connected to the phone to change settings.

   

What features does the processor unit offer?

Processor units are best known for their programmable settings. There are a whole range of programs and subprograms. Each processor unit has a different range of settings and number of programs, but the basics are always similar – shooting mode settings, battery under-voltage monitoring, and active brake are among the basic settings. However, there are many more options. 

Trigger sensivity settings

Thanks to optical sensors or a Hall probe, we can adjust the trigger sensitivity. This is set either via the app or through the trigger, allowing us to fine-tune the sensitivity according to our preferences.

Our tip:
Some manufacturers also sell imitation triggers for their processor units, similar to those found on real firearms. For example, the manufacturer Perun airsoft produces so-called Clickers for its processor units, which make shooting very similar to shooting a real firearm.

Shooting mode settings

We can also set the firing mode for each switch position separately (usually SEMI and AUTO). In this mode, we can set the type of firing for each position of the firing switch. Here we can have SEMI, burst (adjustable number of pellets) or full burst. For special operations, SEMI or AUTO can be deactivated via the processor units.

Reducing the rate of fire (ROF)

Reduces the rate of fire in auto or burst mode for more realistic weapon behavior, or if the replica has such a high rate of fire that the magazines cannot keep up. At the same time, ammunition consumption is reduced. 

Piston pre-cocking

Winning a game is often a matter of fractions of a second. Thanks to piston pre-cocking, you get a trigger response similar to a real weapon. This feature allows you to pre-tension the piston just before the point of firing, so that the piston does not have to travel its entire path when the trigger is pulled, but only part of it. This significantly speeds up the trigger response. This feature puts strain on the spring.

Battery protection

Protection against excessive battery discharge. Modern Li-Po and Li-Ion batteries are very sensitive to excessive discharge. If you don't want to damage the battery and care about its lifespan, this protection is indispensable. The battery type and number of cells can be set in the processor unit settings, or higher-quality processor units will read this data from the battery themselves as soon as the battery is connected to the gun. The microprocessor constantly monitors the battery voltage. When the voltage drops to a critical set level, the processor unit provides feedback to the user. 

Magazine modes

This feature allows you to simulate magazines with a lower capacity than those actually used. Depending on the processor unit, you can set the magazine capacity simulation from 1 BB to 250 BB. After firing a predetermined number of BBs, you will have to wait a predefined amount of time before you can fire another shot, as if you were actually reloading an empty magazine. 

Smart fuse

The intelligent fuse protects the battery, motor, and processor unit from damage. Thanks to the combination of current, voltage, and temperature measurements, you are constantly protected and informed about the measured values when using the app. It protects the processor from overheating, overloading, and short circuits, even in the event of reverse battery connection. If your airsoft gun jams, this feature will protect the motor and battery from damage.

Mosfet

Want to achieve a higher rate of fire and faster trigger response? Mosfet is here for just these requirements. It directs energy from the battery directly to the motor. This gives you a higher rate of fire and faster trigger response.

ACTIVE BRAKE

The active brake (AB) stops the motor after firing, preventing the spring from remaining compressed and eliminating the problem of double shots in SEMI mode in high-rate-of-fire replicas. Braking can also be completely disabled. It is recommended to disable braking or use it at the lowest level when using brushless motors. These motors already include some of the processor unit's functions as standard, and failure to follow the manufacturer's recommendations regarding processor unit settings may result in damage to the motor or the unit itself.

Automatic test and diagnostics

The automatic processor unit test is the first of many ways in which the processor unit protects the weapon from damage. This test always occurs after the battery is connected, when the unit checks for any faults and also tests the battery, determining the number of cells and its charge. If everything is OK, we can use the processor unit; otherwise, we will usually receive a vibration response indicating that there is a problem.
Diagnostics is another indispensable part. This feature allows you to detect and subsequently resolve problems with the processor unit if any anomalies are detected. This mode runs silently in the background and constantly monitors all critical functions of the processor unit. If any error is detected, it will alert you to the problem with vibrations or an acoustic signal and prevent further use of the weapon until the problem is resolved. 
Thanks to live diagnostics, you can quickly check during the game, for example in the app, whether the processor unit is working properly, whether it is overheating, etc. 

Mode for DMR weapons

DMR mode allows only semi-automatic shots and limits their frequency. Its main use is for powerful DMR-type replicas, where we simulate real firing delays. This mode is also suitable for playing fields that require such restrictions. Intervals of 0.25s, 0.5s, 1s, 2s, and 3s are available.

DSG mode

It is recommended to have this feature enabled when using DSG gears to ensure the correct cycle.

Binary trigger

Allows for quick double shots in semi-automatic mode. When this mode is activated, if the weapon is switched to SEMI, the weapon will fire not only when the trigger is pressed, but also when it is released.

2-stage trigger / AUG

The 2-stage trigger, also known as AUG, allows us to set two different trigger sensitivities. With a light pull of the trigger, you shoot in SEMI (or BURST) mode, and with a full pull of the trigger, you have BURST or AUTO mode.

Is the processor unit worth it and what is our recommendation?

In our opinion, processor units are the best choice. There are many manufacturers and types of processor units on the market today. Based on our many years of experience, we can recommend the manufacturer Perun airsoft. Thanks to their price, simplicity, and programming options, they are really great, and we use them in our replicas ourselves.
They can also be combined with Clickers (imitation of a sharp trigger).

If you are looking for a processor unit with the option of connecting to a phone, you can choose from manufacturers GATE or Jefftron – Jefftron is even a Czech manufacturer. Jeftron manufactures processor units for both V2 and V3 mechaboxes as well as for the Scorpion EVO. 
These are also reliable processor units.