I bought an inflatable dinghy and electric trolling motor and am planning to make it controllable via RC to control the steering via H bridge motor controller (L298N) to control a 24V linear actuator (1-2A continuous current, 30 Watts).
I would like to use the Arduino to interpret the RC transmitter and controller to send PWM signal to the L298N H bridge for the linear actuator (steering), and PWM 5V to the 200A PWM motor controller potentiometer to control the speed (forward/reverse).
I bought the trolling motor (model P300) from Alibaba.com with the following specs:
24V, 70A, 1680W; my battery is 24V, 150AH.
I just bought the Arduino kit to model and test this setup. This is my first Arduino project, and I’m new to electronics so please bare with me and feel free to give me any pointers in regards to protecting the electronic components, as well as the Arduino from getting fried. Should I consider back EMF, etc?
I have a few questions to start with.
The L298N H bridge can draw 25 Watts of power. I have not bought the linear actuator yet, but I am looking to buy a 24V, 150N, 70mm/sec, 6” stroke actuator that requires a max of 30 Watts. Will I be able to use the L298N, even though it can’t push the max 30 Watts needed for the linear actuator, or will it work but just not reach its maximum speed?
How to power the L298N and Arduino? Can I use a DC-DC 12V/24V to 5V, 5A, 25W buck converter?
The trolling motor is a brushless DC (BLDC) motor. Any issues with using PWM with BLDC motors? Are there any issues with controlling the 5V potentiometer on the PWM controller from the Arduino?
I have a lot more questions in my head that I need to sort out, but wanted to get the general idea and ask for help with any caveats I can’t think of. All advise and suggestions are welcome! Thanks for listening.
How about a link to the motor not just the Alibaba front page?
Your controller is for brushed motors. You say the motor is a brushless motor. These don't generally work together.
I wouldn't use the antique L298N for anything and I certainly would try to run one anywhere near it's maximum spec. There are many better motor drivers available now. E.g. have a look at Pololu - Brushed DC Motor Drivers
Your controller is for brushed motors. You say the motor is a brushless motor. These don't generally work together.
Can you advise the reason, as I would generally like to understand the workings of PWM better. I wanted to learn Arduino and start to understand electronics at a level to understand how it works. Would it cause any damage to the motor electronics if I used the PWM controller with the motor directly?
I wouldn't use the antique L298N for anything and I certainly would try to run one anywhere near it's maximum spec. There are many better motor drivers available now.
Thanks, I’ll definitely take a look at pololu link you provided. I got the idea to use the linear actuator from Linear Actuator Arduino Control L298N with RC Transmitter and Receiver
That’s why I chose the L298N controller. But I will definitely heed your advice on getting a better motor controller for the actuator.
Unfortunately I can't see any useful information on the page you linked.
In general a BLDC motor has 3 leads not 2 and needs a specialised motor driver because it needs some complex electronics just get it moving. It may be that your motor has a built in controller. I can't tell from the little information on that page. Either way it has nothing at all to do with PWM.
No, it can't. It can switch 1A continuous current to a load, but more than that causes it to overheat and shut down. And it cannot support the start/stall current of the actuator, which is probably around 7A.
You will have to replace that ancient, inefficient L298 with a modern motor driver. I use this one with 24V linear actuators: Pololu G2 High-Power Motor Driver 18v17
I’m connecting the PWM to an already working brushless DC trolling motor, not to a stand alone BLDC without the electronic means to control the commutation of the motor (electronic methods to charge/not charge depending on the position of the rotor and stator, i.e., with hall effect sensors, etc) so I think it’s safe to assume that the electronics to get it moving are already there. As I mentioned, it’s already a working motor. Not a BLDC motor built from scratch.
I could just connect the PWM to the trolling motor right now and find out if it works. My concern would be if doing so could damage the PWM or the trolling motor. I don’t want to fry the electronics without proper precautions. Any other precautions I am overlooking such as back EMF, current ripple etc that I need to be aware of, or could you suggest precautions to take before connecting the PWM to the motor so that I don’t damage the electronics of either device?
So why not go the route of buying an off-the-shelf rc tx rx and go from there...???
Many cheap units such as an FS-i6 have many features, enough to do what you want and keep you busy for ages, and at the same time, eliminating what will surely be, a weak link.
Thank you very much and I agree that I will need to swap out the L298N. I saw on the pololu page that the 18v17 you suggested:
Note: Battery voltages can be much higher than nominal voltages when they are charged, so the maximum nominal battery voltage we recommend is 18 V (and use with 24 V batteries is notrecommended) unless appropriate measures are taken to limit the peak voltage.
Would the 24v13 or 24v21 be a better choice with a max nominal battery voltage of 28V, compared with the 18V max nominal battery voltage of the 18v17?
I bought the boat and motor first to enjoy it on the lake. I plan on hacking it because it seems like a fun first project to try. Whether it works or not, I still plan on using the boat.
I’ve seen YouTube videos already of people using RC tx rx, with the L298N and Arduino to control a linear actuator. So I know that part works.
The part I have a big question mark with is if I can control the 200A PMW controller with the Arduino/RC to control the PWM with the 0-5V potentiometer, and forward reverse.
In case you wanted to know what RC tx rx I plan on using, I already ordered a Radiolink RC6GS.
Yes, of course. I actually use an 18V drill battery in my installation, as I don't need the full power or speed of the 24V actuator I had on hand. Actuator voltage ratings are nominal in any case.
What others already said, you don't need Arduino for this. That's making it more complicated than it needs to be.
What you're looking for in a motorcontroller is one that is capable of 6S, meaning 6 cells of 3.3 nominal voltage. Google 'ESC 6S brushed' for more options.
Your trolling motor pulls 70A if I read the data correctly.
So I would start with something like the HC960A to experiment with. It connects to a standard RC remote control receiver and is affordable https://www.aliexpress.com/item/32846485854.html. I'm sure there are water cooled high power esc's as well but that's up to you to find those.
I want to thank you for pointing me in this direction. I really had no idea RC motor controllers were capable of such high Amps and voltage!
Can you tell me if the ESC uses PWM and is able to control the speed of my brushless trolling motor?
I’m looking at the HC960A, and it’s a little confusing to me. Can you explain what Crawler mode/No Brake mode, and which one I should use for a boat?
the total length of the power cord should not exceed 20CM
That seems unmanageable to me on my boat. Does the ESC really need to be 20CM from the battery or can the 20CM be to a busbar?
For steering I'd suggest two 60Kg servo's
First off I’m really amazed they even make servos that large. Can you explain why you would need 2x servos? Or point me to an example of how to rig up two servos for steering? I can’t visualize why you need the 2x servos or how to implement it versus one.
Thank you very much for opening a new path way in my brain and opening up a whole new world of RCs and servos as an option.
Both signal wires of both servo's go to the same pin of the receiver so they move the same direction. You'll need to do some snipping and soldering to connect the servo's to their power supply and signal wire to the receiver.
Easy....mechanically link a servo output arm to the pot.
If you need 270 degrees pot travel, connect it from the servo output via step up gearing....works, I've done it before........
