How to Connect this Bubble Machine

Hi everyone,

I’m a long time lurker, built my own quad using an APM 2,6 and one for a friend. Both work very well after following all the useful info on this site.

I’m looking for a bit of help. I bought one of these

And thought it was going to be simple to add. The bubble maker is a simple motor, there is no PWM or other control signal, when connected to 6V it spins and works. However, I just cannot understand how I can control this via the APM.

I think I need to use A9 as a relay(?) but I’m really strugging on how to wire everything up.

Any help would be greatly apprciated, and a circuit diagram would help :slight_smile:



Why not just control it from a servo out and switch on your TX?

Hi Gary,

I am very green at setting up the transmitter/receiver so apologies if I sound a bit simple.

I have set up on my transmitter ch7 switch and on Mission Planner I can see that toggling from low to high when I operate the switch. Are you saying it’s as simple as connecting the bubble machine to Channel 7 output of the receiver (NOT the APM)?

Thanks again Gary


Hi Gary,

I have my a switch on my transmitter set to CH7 and on mission planner, it goes high/low when the transmitter switch is operated. Are you saying all I need to do is connect the bubble machine to channel 7 of the receiver not the APM? There is no PWM control signal to the bubble machine, its a simple motor.



You need a PWM to O/Off switch like this:

Thanks TCIII, one on order, I shall let everyone know the outcome

Thanks for your help, I didn’t even know those switches existed!


Is the PWM on/off switch the only way to do it? I am in a similar situation, where all I need is for the switch on my transmitter to turn one signal pin from 0v to 5v. I figured setting channel 7 to Relay On/Off (CH7_OPT = 28) would fit the bill perfectly, but it doesnt appear to do anything to pin A9.

Surely theres some way to do it without additional hardware?

You need something to drive the motor, the PIXHAWK’s outputs won’t supply enough current. You could probably do it with a relay or a single transistor and resistor from radioshack. Will the bubble blower run on 5V?

Well I ended up buying one of these … EBIDX%3AIT

It worked a treat, however the bubble machine was utter pants, I’ve dribbled bigger bubblles. That was 5 quid up in smoke!

Thanks for all the help people!


You could try getting it the specced 6v by plugging it into 4 AA batteries. If it still sucks, increase the voltage until it either doesn’t suck or doesn’t blow.