Using Arduino for a cable cam motor and gimbal control via wifi.

Hi there.

My name is Jonty and I'm in my 4th year doing Product Design and Manufacture (MEng) at Nottingham University.

For my major project I have been designing a wifi controlled cable camera for a GoPro, and am about to start computer modelling my design. For this I need to know what electronics I am going to be using so I can model my parts around them.

I haven't had much teaching in electronics so I feel very lost as to what I need to be using, so would really appreciate any help or advice anyone can offer.

The design uses a motor to drive a main wheel which will allow the unit to travel in both directions along a wire/cable, as well as a 3-axis gimbal for the gopro camera. Both of these will be able to be controlled via an app on a phone/tablet for the position on the wire and the movement of the camera in the gimbal.

So far I understand that I will need an Arduino Uno, an Arduino Wifi shield to receive the signal and an Arduino motor shield to drive the motor. I would also like to have a small LED screen, and an on/off switch for the system and i'm a bit confused as to what else I would need/if I am correct in thinking these items are what I need already.

If possible I would also like some advice on what I will need to connect to the gimbal - the ones I have been researching come with their own board and I am unsure if I can just connect these to the Uno or if I will need something extra.

Many thanks for reading, and thank you in advance for any help.

Jonty

jontywhiter: So far I understand that I will need an Arduino Uno, an Arduino Wifi shield to receive the signal and an Arduino motor shield to drive the motor. I would also like to have a small LED screen, and an on/off switch for the system and i'm a bit confused as to what else I would need/if I am correct in thinking these items are what I need already.

If you definitely need WiFi you should consider using a Yun. It has the advantage of a complete Linux computer as well as a "Leonardo"

Either way, you don't necessarily need a "shield" to interface with a DC motor. You can buy h-bridge motor drivers that are not shields. They might give you more connection flexibility.

Rather than have an LED screen you could "view" the output on a browser on a laptop or tablet that connects with WiFi. This EzScrn project I have been working on might give you some ideas.

...R

Thanks for the reply! Having a look now

If you've been googling for inexpensive gimbals you've probably found the one based on a MultiWii controller. These use servo control signals and require no extra driver -- just three lines from the Arduino.

If you want good speed control of your motor as it rides across the cable you should use a stepper motor. With a typical DC motor the speed will vary based on how much load the motor is pushing (varying inclines will cause uneven speeds). With a stepper you can command precise rotational speeds, or with a DC motor with an encoder you can get feedback on the speed and adjust current accordingly -- the latter being a bit trickier in software but still doable. Small, NEMA17-size steppers require a "Stepstick" to drive them and DC motors will require a motor driver capable of supplying the necessary current, but whatever you do you should avoid the motor shields based on L293 chips. They're old technology; there are better solutions available.

Is the gimbal stabilised? Then get one of the off-the-shelf items which has its own microcontroller on board. (Many of them use the same processor as an Arduino.) It should have 'servo' inputs to control pitch, roll, yaw. Use the Arduino servo library on your 'main' controller to drive those inputs.

Thank you for the help. I will definitely be using an off-the-shelf gimbal, and have seen the one based on the MultiWii controller, but I would ideally like a 3-axis stabilised gimbal with its own microcontroller, does anyone know of any good off-the-shelf versions?

I definitely will be using a stepper motor after what you have told me Chargin, it seems far more appropriate.

So currently I know believe that I need:

  • An Arduino Uno
  • A stepper motor and 'stepstick'
  • A yun or wifi shield to recieve the signal
  • A 3-axis gimbal with it's own microcontroller
  • Appropriate battery

Does this sound a bit closer?

Thanks again for all the help.

These gimbals have yaw stabilization -- do you need that on a cable-riding camera? Couldn't the gimbal be positioned for pan and tilt control and stabilization?

If you plan on controlling this camera wholly manually then it might be a better idea to just use a full RC setup for the control. Gimbals are already compatible with servo control signals so all you would need would be one more hefty servo configured for continuous rotation to run your mount across the cable -- not as smooth as a stepper but much less expensive, lighter, and less power hungry.

What are you planning on using this camera for - timelapse photography or e.g. shooting a sporting event?

The rig will be used for filming sports like downhill mountain biking, skiing, or anywhere where you can set up the cable to a rigid object. So no timelapse function. I'm going to have a look at a few gimbals etc and see what I can come up with and report back.

Cheers for the help again.