2.5 Amp Motor Controller

Question

Does the same procedure apply to connect the 2.5 amp motor controller to the v4 compared to the v3 2.5 amp motor controller

Rich · Answer

Yes. Just be aware that the 5V in on the H-Bridge needs to be 5V. It wasn't an issue on the V3 as all ports were 5v on the VCC, on the V4 VCC of each port is the same as Vin, so it could be anything between 4.5v and 16v. The H-Bridge wouldn't like that, you will want to put a 5v regulator inline.

Mohamed.r · Answer

Thanks rich does anyone now when the next set of hardware tutorials will come luckily I saved a few of the pages on my home screen so I can access it now when there are not on the website

Rich · Answer

They are being added at the moment one by one. I plan to update my H-Bridge tutorial to cover the V4 as soon as I have a 5V regulator to use. In fact, I plan to update all of my tutorials to cover the V4 when I get the chance. If there is anything specific you want to have covered and EZ-Robots haven't got the new tutorial up or if it's not quite clear enough just shout and I'll see what I can do. Provided I have the required parts I'll gladly throw a text/photo based tutorial together.

bstaehling · Answer

Hey, I'm not 100% certain on this, but I don't think you need to use the +5V input on the 2.5A H-bridge. I think if you supply Vcc, just make sure the little switch is depressed and it uses the linear regulator that's already on the H-bridge board to get 5V from the Vcc you supply it. I'd appreciate it if someone could confirm this.

Mohamed.r · Answer

I am still waiting for my ez robot complete kit to come so I can make my robot it is going to be like boxbot first I will build the original version and the I will add thing like sensors grippers etc and as I go along I might do I few tests like adding a motor and an h bridge so that's why I asked this question.For now I do need any specific tutorial but thanks for asking if I need any tutorial in the future then I will let you know

Dave Schulpius · Answer

I'll be refitting another V4 in place of one of the V3's into my B9 today. I have the V3 now attached to one of these H-Bridges I bought from EZ Robot last year. I'll take some tests and come back later today when I get the swap completed. bstaehling is correct thought this H-bridge does have an onboard regulator that you can be enable/disabled when the button is pushed. Now if it will accept a voltage as low as 3.3 and convert it properly is the question. I've already ran into one instance when retrofitting my first V4 where the supplied 3.3 vdc signal pin on the V4 would not switch a Mosfet on one of my homemade high side power switching boards. The 5v of the old V3 operated it just fine. eyeroll

bstaehling · Answer

Thanks for checking Dave. I took a closer look at the 2.5A H-bridge circuit I have. The regulator chip on the circuit is a linear regulator, ST Micro 78M05. This chip will regulate input above about 7V or so and drop it down to 5V. To be certain it will provide regulated 5V, supply voltage must be 2V higher than the 5V output it is rated to. If you supply lower than this dropout voltage, it will still pass voltage through but it won't necessarily be 5V, it will be 5V or lower (unregulated, basically just operates as a 5V limiter). If you give the regulator 3.3V in, for example, it will output 3.3V or less. The data sheet for the ST Micro L298 full bridge driver says it will accept 4.5V - 7V for logic supply voltage, so I'm guessing the H-bridge circuit won't run with 3.3V.

bstaehling · Answer

I'll also note that the L298 chip will accept 2.3V or higher as logic high. If you can provide sufficient voltage at Vcc and/or the 5V input for the logic side of the L298 chip to operate, it looks like a good chance it will accept 3.3V signals to control it.

Jeremie · Answer

Hey guys I can confirm a few things for you as I use the 2.5A motor controller here at the shop quite often.

The controller does have a 5V regulator on board that supplies the L298 with the voltage it needs as long as you provide (as @bstaehling mentioned) 7V or higher. Only one power line and ground required to attach it from your v4 (fuse protected) or directly from your battery. Just remember to tie all the grounds together.

The controller also accepts 3.3V TTL logic and works flawlessly with the V4 providing the inputs signals, just hook up 4 digital pins from the v4 to the motor controller input signal lines and optionally 2 to the enable lines (pwm h-bridge control) and you are on your way.

Mohamed.r

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