Is it feasible to power an external device directly from variable Arduino voltage output?

Projects General Guidance
1

I don't even own an Arduino yet, but I am just wanting to check whether this project is feasible first.

What I would like to do is put an "exhaust" pipe on a bicycle that pushes out bubbles. The amount of bubbles depends on the instantaneous acceleration of the bike.

The basic idea is:

  1. Measure acceleration using an accelerometer (presumably with an arduino)

  2. Map that acceleration to to a value within some output voltage range and actually send that voltage out (presumably also from the same arduino). (I dont expect to have any problem implementing the code for this... I have already done accelerometer apps before on Android, for example)

  3. Connect this voltage directly from the arduino to a modified bubble gun

The main problem I would expect to run into is that the arduino is going to be limited on how much current it can supply... and the bubble gun may exceed that... so some intermediate power supply might be needed, but I don;'t know what that would be or how that would work.

So, my basic question is whether it is trivial to do this? Are there any existing concrete tutorials that do something similar?

2

The maximum recommended current from an Arduino (Uno, Nano, Mega) is 20mA. Other processors vary, but are mostly the same or less. So you will need an external power supply and a driver that you control with the Arduino that in turn controls the motor.

The driver can be a simple MOSFET driver for a motor that does not need to be reversible. The motor speed can be controlled by PWM (Pulse Width Modulation).

mosfet motor driver
mosfet motor driver840×654 43.7 KB

Or an H-bridge motor driver for a motor that runs in both directions.

3

Most Arduinos do not have a "variable output voltage." analogWrite() is normally PWM.

4

The Arduino can send control signals that steer a motor or open a valve, and provide power for a couple of LEDs or a sensor.

The stuff that does the real work in your project must have its own power supply.

5

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