
woodylv

Hello All.
I need a suggestion for a motor controller to drive 2 arms that are connected to 2 screw drive actuators. (Aproximately 2 amps each)
I wanted to get some advice before I purchase anything.
I bought some other controlers with out thinking and they ended up not working.
I already have a sabretooth driving the wheels so I need something else that would work with a joy stick or a button pad.
Thanks for any advice.
Michael
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Although don't give up on your other one yet, I'm sure we can make it work.
Thanks as always for your input.
I can tell you what happens is when I try to connect my other motor controler using the pwr in (The 12 v for the motors) Nothing happens
When I switch it to the Vin(From the EZB) It causes a power circut issue which has been blowing boards.
And it makes my bot run in circles
Plus for $15 its not worth the hassel.
But if you have any more sugestions I am open to them.
How can I use the PWM and Digital controls to work with a joy stick ?
Servo Power Boards
Do is till need the regulator:
Servo regulator
And, can't I control the arms without a motor controller? I will use the dual H-bridge for the base.
That's the plan anyway.
The L298n is 2.5A. I don't know if that's total shared or per motor - you may need 2 if your motors use 2A and you plan to move both at the same time. Try it on one first, it should only brown out if it can't drive both.
Using it with a joystick may be a little bit complicated as you already have a Movement Panel so can't add a second. You will need to write scripts for each movement i.e. left arm up, left arm down etc. Then call those scripts in the joystick configuration for when a button is pressed. I don't use joystick so am not sure if you can map anything to the stick that isn't a servo or Movement Panel though, but I'm confident we can get something sorted on it.
Once it's wired up and working we can tackle the joystick part.
To check it's working just write a few scripts and run them for each movement.
Assuming D0, D1, D2, D3, D4 and D5.
D0 - In1
D1 - In2
D2 - In3
D3 - In4
D4 - PWM Motor 1
D5 -PWM Motor 2
Motor 1 Forwards Full Speed
Code:
Motor 1 Forwards Half Speed
Code:
Motor 1 Reverse Full Speed
Code:
Motor 1 Reverse Half Speed
Code:
Motor 1 Stop
Code:
Motor 2 Forwards Full Speed
Code:
Motor 2 Forwards Half Speed
Code:
Motor 2 Reverse Full Speed
Code:
Motor 2 Reverse Half Speed
Code:
Motor 2 Stop
Code:
If you save all of those as separate scripts in the script manager control you can call them as required with ControlCommand(). You can assign each one to a button press on a joystick, and on button up assign the stop script. If that doesn't make sense I will do a quick tutorial with screenshots to show it when I have ARC in front of me.
It's always a good idea to put in limit switches if using motors and a H-Bridge to control things like arms. This way if, for any reason, the motor doesn't stop moving the switch will kill the movement saving you from damaged robot bits. I think Dave as something like this set up on his B9 build.
However I'm not quite sure where the external servo power board comes in to play on this topic. @woodylv is planning to use motors & a H-Bridge to control arms not servos. I assume he has his reasons for doing so.
thanks,
Download it here
As always thanks for the consice input.
The reason I am trying a motor controler is that the devices connected to the arms are actuator type screw drive motors.
I was not involved in the design of this.
So if I put 12v to the wires the arms go up. When I reverse the polarity they come down.
I was assuming that a motor controler was the only way to go but maybe I am mistaken.
Do you think I should use a H Bridge or Motor Controler or do you have other options ?
I think that calling the script from the buttons will work just fine.
I am wondering how to put the limit switches on the screw drives since its sealed but maybe you can help on that too.
I think I am at the near end of this issue just need to buy the controler.
Let me know what you guys think.
And thanks again everyone for your input.
Later,
Michael
With limit switches, you may want to make a new topic asking about those. I've not used them but know other users have. They should be able to give more details but may not have seen this topic.
I ordered ten of the HJ S3315D.
Thanks again for all the help guys.
Later,
Michael