2 replies to this topic

[MagnusBuildsComputers]

Hello nerfers!

 

So I had a idea to make a select fire stampede. My thoughts were to perhaps do it with an ardunio

 

So I was going to have a circuit where the negative wire of my 3s lipo is connected to the negative terminal of the motor, and the positive rail is going from my lipo would be connected to the collector of a transistor, with the ardunio hooked up to the base and the motor connected to the emitter. 

 

So when the trigger switch is activated, then the ardunio would send a signal to the base for a certain amount of time, then stop, the amount of time depending on a switch wired to the ardunio for the firing modes such as semi, burst and full auto. This would allow the current to flow from the collector to the emitter, making the motor run for a specific amount of time.

 

Sorry if that's not very clear, but what are your thoughts? Problems? Any help would be appreciated. (Especially with programming)

Thanks

Magnus 

(forgot to include trigger switch in the diagram and explanation, it would be connected to the ardunio to control when it sends a signal)

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[DjOnslaught]

There was a arduino thread for this blaster started by Kingbob that me and him worked on in the thread and he did that. Reference that thread for help

[Kingbob]

What you're proposing will work to drive the motor, but, the time to run the motor will vary by voltage. If you run it from a lipo it will turn faster so need to run less time.

Instead, use a switch to detect when the firing plunger has fired, and then stop the motor. Don't need to time anything then, can just run the motor until the switch is pressed.

I'd also put a pull down resistor on the arduino pin driving the transistor. Otherwise when the arduino turns on, the voltage on that pin might briefly go high and run the motor.
Also, think about using a h-bridge instead of transistor. Can run it from a pwm arduino pin and control the speed more accurately.