Laser Blaster garden game - kinda working but hardware advice needed

Using Arduino Project Guidance
1

Hi all

I'll go through this as logically as possible...

Project description
I've been making a laser blaster game for about 7 years now. I kinda drift in and out of it so it never gets my full attention. In short, the blaster uses an Arduino Nano and has three inputs - trigger, align switch (this turns the laser on permanently for alignment purposes) and a 3 position rotary switch so there's 3 firing options - single shot, 3 shot blast and full auto.

In terms of outputs, the Nano sends a signal direct to a sound board for a blaster noise and the laser and 6v 2a recoil solenoid are each handled by a STP55NF06L Mosfet. The whole thing is powered by a 2s lipo. Image below is the wiring diagram and below that an image of the board. Not shown in either image is the flyback diode on the solenoid and the voltage regulator that's soldered to the laser module.

Blaster diagram
Blaster diagram1020×674 198 KB

20241103_202905
20241103_2029051920×754 215 KB

Issue
Single shot works fine but on 3 shot burst, the solenoid can lock sometimes rather than recoil. In full auto mode, the solenoid will lock after a few shots with the laser staying on too. Its easy to reset though with the nano's on-board reset button or a quick power cycle.

How I think it can be resolved
Firstly, I don't believe its the code causing the issue as the system does work, at least for a little while. Having had a read online, what I believe is causing the issue is the lack of any resistors on the Mosfet circuitry. However, I'm confused about where they might go, the required resistor values and whether, most importantly, that adding them would solve the issues I'm having.

Any advice would be great!
Cheers
Dan

2

Use a 180 - 220 ohm resistor between the gate and the output. Connect a 10k ohm resistor between controller output and GND.
Make sure the FET is a **logic level N channel MOSFET **.

3

thank you. So the 200ohm resistor is connected to the gate and drain/ output pins of each Mostfet? and the Mosfet pins on the Nano are to have 10k resistors connected to GND too? Want to make sure I'm understanding you right!

4

No!
Connec the 200 ohm resistor between each gate and its controller output.
Yes. Each controller output should have a 10 k connected to GND.
Sorry, only a tablett in use, no Pc and drawiings available.

5

See e.g. the schematic at Gammon Forum : Electronics : Microprocessors : Driving motors, lights, etc. from an Arduino output pin. You're also missing a flyback diode (D1 in linked article).

These might or might not be the cause of your issue.

6

thank you. get it now. I think i can bodge my existing PCB and components quite easily to fit these in so that's good.

If this isn't the issue, its got to be a component issue somewhere.

7

Fitted some 200 and 10k resistors as suggested as its working much better. Thank you! its still getting confused on the full auto setting though after a handful of shots, almost as if the system can't keep up with itself. Any ideas?