Hello guys, I just recieved my controller board and Im in need of help right now.
I have got an hybrid stepper motor (can be setup as a bipolar or unipolar), and the controll board I ordered is called Dual H Bridge DC Stepper Motor Drive Controller Board Module L298N .
I think Ive understood how to make this work, but Im stille unsure and would like to be on the safe side before I start to put this together.
As you can see there are two channels, A and B that has to be activated. And there are 4 inputs, and from the digital inputs from the arduino I shall connect em together.
When that is done, I have 4 outputs. Output A and output B, each got 2 ouputs. This is where I should connect the wires from the stepper motor. But the question is, in what order?
Here is how the ports look like:
If you'd like to see full description on the controller board, you can find it here
I gave it another shot now. I also gave it 5v through the "+5v power", AND it started to shake as hell when I compiled the code.
It gave me a small rotation but then stopped and vibrated really strong.
Also the L298N chip got really hot, so that was not so clever of me I guess.
But I read that the chip needs 2 voltage inputs, one for the chip and one for the motors.
However, does any1 understand what he really means with this?
This module is integrated with a built-in 5V power.When the drive voltage is 7V-35V,
it can enable the onboard 5V logic power supply;afterthe power supply,don't input
voltage in the interface+5V power supply,but you can lead the 5V for external use.
So, as Ive given the module an input voltage of 14V, I should not be in need to input the 5V necessesery for the chip itself?
Chip_Partner makes two contradictory statements in his ebay presentation:
2.This module can use built-in 78M05 for electric work via a driving power supply part. But to avoid the damage of the voltage stabilizing chip, please use an external 5V logic supply when using more than 12V driving voltage.
-- and then --
This module is integrated with a built-in 5V power. When the drive voltage is 7V-35V, it can enable the onboard 5V logic power supply; after the power supply, don't input voltage in the interface +5V power supply, but you can lead the 5V for external use.
/*
The placement of "5V Enable" shunt isn't shown on the ebay schematic. If you're supplying 5V, from an external source, I suppose that that should be pulled out.
The L298's "logic supply" (the 5V) is called, by them and absurdly, VSS. The motor supply is called VS, just to keep things confusing.
So far as how to place the stepper wires, if you trust your 'sketch' then just swap them around till it starts rotating; jack-rigging it like that won't take it down.
*/
So if the voltage supply is more than 12V I should use an external 5V supply, so that is what I did and I also pulled the jumper out so that the 14V cant supply the chip, instead the 5V will do so.
But nothing happened.
So I placed the jumper back and the stepper started to rotate atlast! But the chip is still getting really heated. So there is clearly something wrong with the volt supplies, now we do know that..
Any conclusions?
Edit:
By watching the schematics on the link provided. I cannot see that the +12V by any possibilities is providing any voltage to the chip. All I see is that the +12V is connected to the motors.
I also used a 7.2V battery, it did not heat up that fast but after like 20sec it started to get hot.
Is this normal?
The L298 will run rather hot which is why your board is provided with a heatsink. The chip does have overtemperature protection so it should shut down before any damage is done. For driving a stepper with the L298 I would suggest using an L297 chip which provides for current regulation which can minimise overheating. It also provides switching logic which simplifies the input signals to simple step and direction.
I also suggest studying the data sheet which will explain all this.
I will attach the data sheet and application notes to this post.
I see, they are explaining how to combine the l297 with the l298 chip in the datasheet.
Well, so Im not doing anything wrong then. Is this overheating something normal?
Because it does say that you dont need to input +5V to the Vss (for the chip) if you are supplying the Vs with 7-12V (for the motor). But in my case that does not work.
I must supply Vss with 5V.
I mean, why do they sell this kind of stuffs if they get overheated? I dont see the point...
Well, like I said, it is normal for that chip to get hot, nothing out of the ordinary there. The board may be defective in that it won't let you use the 5V from the onboard regulator. But I wouldn't complain. The chip and heatsink alone are worth the $5.47 you paid!
What is the current rating of your motor? If it is more than 2 A you will definitely need to limit the current. (actually, like most manufaturers ratings 2A is optimistic).
It says that the current/phase is 1.8A, so I guess I shouldnt worry. And that I also should be glad cause of the price of this board hehe
I actually got things working now, Im using a battery with 5V for the motors and its way less heated compared to when I input 12V.
How about the rpm, the thing is that I want to make myself a frameless laserharp but it doesnt seem to be as fast as I need it to be.
What do I need to consider making it faster, is it the ampere or the voltage?
freak174:
What do I need to consider making it faster, is it the ampere or the voltage?
The speed is determined by the rate of the Inputs (Gray) code. The faster those update, the faster the rotation, but only up to a point - that's where the speed of the code >= the motor's ability to keep up, to go from one position to the next.
I felt the need to put my 2 cents in after reading this page almost 3 years after the fact, mostly for people like myself searching for information on this circuit board.
The way I understand it is the 5v is an output only. it comes from a 5v regulator that is fed from the 12v or main power input. It's used to power the logic (Arduino) that steps the motor . If you are feeding the board more that 12v, then you will overload the 5v regulator. In that case, use a separate 5v power supply to power the logic & remove the jumper to separate the regulator from the power supply.
Also: I find it very informing to use a continuity tester to probe out unfamiliar circuit boards (Not powered up of course). If you probe this circuit, you will notice how it is wired. With & without the jumper.
a little bit out off the topic, forgive me, I am new here. Opinion on where to find similar drive controller
under this price. I heard I can get one for less than $100, for a 3D printer.
