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How To: Use a L298N Dual H-Bridge with a Microcontroller (QuickStart Board) - Page 2 — Parallax Forums

How To: Use a L298N Dual H-Bridge with a Microcontroller (QuickStart Board)

2

Comments

  • whiteoxewhiteoxe Posts: 794
    edited 2014-07-14 02:12
    When I went to convert the video to a file to upload I had never seen so many different fikle conversion options. For me it was very confusing. Im sure you will be far more familiar as to what type of file you wish to upload. I made a couple of silly errors, I should have put in another diagram or any picture when I realised I was still talking while the screenj went blank.
    And Im just throwing breadboards and things around to demonstrate ive not thought out yet how to put it all together yet. I actually am even thinkin of getting acouple more of those motors and wheels and making this a 4wd, if I think I can line everything up correctly ?
    But if you want to try the easy VSDC movie editor google it and get it from its own site so you are not asked to download other stupid programs. My main disapointment was a logitech webcam was doing close ups better than the DSLR camera i purchased.(only with video, the DSLR can take better closer macro shots) It is far easier to use than those expensive video editors that often are included when you buy a new video camera. Pinnacle and the like, yuck !

    http://youtu.be/1jlAX52zaVA

    PS. The format I uploaded , youtube said it did not recognize it but would try anyhow...... well it did upload and play as you can see on the link but the quality did suffer a tiny little bit.
  • SavageCircuitsSavageCircuits Posts: 256
    edited 2014-07-14 09:23
    Duane Degn wrote: »
    I was finally able to convince The Raspberry Pi Guy to make his video private. I had made several comments on the video page pointing out the error, I sent him several emails on the subject (getting progressively harsh). But it wasn't until I started listing the Raspberry Pi boards which had been burnt out as a result on his video on the Raspberry Pi forum that he finally took action. I searched Google for the video's URL and I saw there were a bunch of links to the video in the Raspberry Pi forum. Wouldn't you know it, most of those links turned out to be questions concerning burnt out Pi boards from following the directions on the video. It was really depressing reading the various threads. I'm having a hard time not feeling very angry when I think of all the money and time wasted buy this kid's refusal to fix his video. This issue had been raised many times previously. I still don't understand why he wouldn't take action earlier.

    Slightly off-topic, but I have found a great many videos on YouTube from people who are giving tutorials on a subject who don't really understand the subject themselves. It's especially prevalent in tutorials on video software (ironically), but also with electronics and microcontrollers. It would seem you should probably understand the subject completely before trying to teach others.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-07-14 09:46
    . It's especially prevalent in tutorials on video software (ironically), but also with electronics and microcontrollers. It would seem you should probably understand the subject completely before trying to teach others.

    As has been so well demonstrated in the motor controller case. And I think that video tutes are good when you type in exactly what it is you want to do, such as when I wanted to know how to use Green Screen , that was well worth 5 min of my time but I would not sit and watch a general how -to video tutorial for half an hour. I make private videos for myself and upload them, to remind me when I am stuck , I go back to a private youtube vid(if I made one on the subject). I like that a lot about youtube.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-07-14 11:04
    It would seem you should probably understand the subject completely before trying to teach others.

    I agree.

    Just to be sure there wasn't a message for me in there, is there a problem in my L298N video?

    As I've mentioned elsewhere, I usually just make videos showing off my projects. I made my L298N video so there would be an alternative to TRPG's disastrous video.
  • SavageCircuitsSavageCircuits Posts: 256
    edited 2014-07-14 11:09
    Not at all. :nerd: I was referring to the original video you asked him to take down. This person may understand Pi programming, but he obviously doesn't understand about interfacing. I see plenty of videos that are being called tutorials where I have to shake my head and wonder where they got their information. Some of them are even called, *gasp* "experts"! :innocent: A little research goes a long way. Even so...

    I think you did a great job of trying to help people out. I watched your video. :thumb:
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-07-14 12:00
    I think you did a great job of trying to help people out. I watched your video. :thumb:

    Thank you very much. That means a lot to me, coming from you.
  • SavageCircuitsSavageCircuits Posts: 256
    edited 2014-07-14 12:21
    Pretty sure I hit subscribe to your channel after watching that. I don't subscribe to just any channel. :nerd: On a side-note, I am about to purchase my first Raspberry Pi.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-07-16 18:37
    Duane, i hope you like that free vid editor. I think there are so many now since the Microsoft dummed down their video editor that all these extra ones are popping up all over the place.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-07-17 21:35
    Duane this is my last 2cents worth of ideas about how you could improve on the video. First that demo of using the motor without the QuickStart I thought was good. The fact that the motor controller could hardly be seen at times was bad. My latest thought was keep your video editing software. For the close up of the motor controller use a printed out picture of it, the one you have used and make it a fairly big picture and use a pen to draw point out everything. Hope ive not been over helping ;)

    Cheers, Mike.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-07-18 00:54
    whiteoxe wrote: »
    The fact that the motor controller could hardly be seen at times was bad. My latest thought was keep your video editing software. For the close up of the motor controller use a printed out picture of it, the one you have used and make it a fairly big picture and use a pen to draw point out everything.

    I've been thinking about how to show the pins better and earlier today I was thinking I could use a drawing of the L298N board so it's easier to show which pins are which. Since making this video, I've seen a lot of really bad information about these boards. Many people don't understand what the various jumpers are for.

    While I'm not anxious to make many tutorials, I would like to expand on how to use these boards.

    I haven't tried any of the video editing software yet. I've been working on a couple of different projects including getting my Raspberry Pi I received for Christmas of 2012 up and running for the first time (earlier today).

    I'll probably make a similar video to the one in post #1 but using a Raspberry Pi instead of a QuickStart. Hopefully in my next version, it will be easier to see which pin I'm talking about on the h-bridge board.

    I'd like there to be a video which shows the correct way to connect the L298N boards to a Raspberry Pi. I think it's very likely there are still boards connected incorrectly which could be saved if the people who wired them incorrect could be advised of the error. With over 340,000 views, it's likely there are a significant number of boards wired incorrectly.

    Unfortunately the kid (aka The Raspberry Pi Guy) doesn't appear to have any intention of offering a warning about the dangerous connection. He also deletes comments (not just mine) with references to the error. It's almost too bazaar to believe.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-07-18 04:27
    and in your video you also explained how to use the motor controller to power another mc board, the quickstart on your rover. that was very informative to me in a big way. don't leave that out !!!!

    EDIT: AND AS THIS IS ALL AIMED AT BEGINNERS,sorry caps.... what else could I power with that 5volt screw and could the back Enable pins be also used to power ??
  • ercoerco Posts: 20,256
    edited 2014-07-18 08:33
    "Unfortunately the kid (aka The Raspberry Pi Guy) doesn't appear to have any intention of offering a warning about the dangerous connection. He also deletes comments (not just mine) with references to the error. It's almost too bazaar to believe."

    Maybe he's also a seller and his videos encourage repeat customers. Crazy like a fox! And truly bizarre.
  • SavageCircuitsSavageCircuits Posts: 256
    edited 2014-07-18 08:51
    I can't stand it when people delete your comments on something they've posted. It's part of the reason I deleted my Facebook account so long ago and have never gone back. Some people really can't deal with the stuff they post being wrong (and someone pointing it out or offering the correct info). Denial.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-07-18 08:59
    erco wrote: »
    "And truly bizarre.

    Give me a brake!

    So I can stop my robot but keep the corrections coming. I blame Chrome for not turning bazaar red (I'll also blame it on it being nearly 2 am locally). Maybe I need to get an iPhone so I can blame Otto Correct (I hear he causes all sorts of trouble).
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-07-18 09:59
    I can't stand it when people delete your comments on something they've posted. It's part of the reason I deleted my Facebook account so long ago and have never gone back. Some people really can't deal with the stuff they post being wrong (and someone pointing it out or offering the correct info). Denial.

    I delete obvious spam and I'd likely delete profanity (which hasn't been an issue so far) but IMO, it's cowardly to delete criticism.

    Considering the kid's actions, I thought these comments pretty tame (pasted together in the order they would appear)

    attachment.php?attachmentid=109665&d=1405699718

    Currently just the first and the last comments remain.

    I feel bad for the guys who had parts come in before the video was pulled. "Taken down for maintenance" hardly suggests the disastrous consequences of awaiting those who followed the video's instructions.

    BTW, The Ryanteck MCB is a board with a SN754410 chip. The board pulls both the enable pins high. The only control option is pulse/brake. Pulse/coast isn't possible.

    I was going to say it's hard to believe it's called a "much more viable option than the L298N" but then. . .

    I keep telling myself I'm not going to rant about this here but I think this kids behavior should be exposed somewhere and all three threads at the Raspberry Pi forum where this tutorial had been discussed have been locked.
  • GenetixGenetix Posts: 1,754
    edited 2014-07-18 12:51
    The 754410 is based on the LM293 which is even older than the L298. The 298 has an odd "package" while 754410/LM293 comes in a DIP (Dual In-line Pin).

    I remember seeing videos of running a TV off of a battery or recharging and iPod or iPhone with an onion and thinking how is that possible.
  • SavageCircuitsSavageCircuits Posts: 256
    edited 2014-07-18 13:10
    Duane Degn wrote: »
    I delete obvious spam and I'd likely delete profanity (which hasn't been an issue so far) but IMO, it's cowardly to delete criticism.

    Agreed, and that's what I meant. If you enable comments on your video you should expect some people to disagree with you. When you delete the ones you don't like / agree with you're making it look like all you ever get are positive comments. That's wrong.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-07-18 17:26
    circuit_diagram_L298N.jpg
    connect-l298n-to-arduino.jpg
    good  l289n.jpg
    l298n-function_-900x700.jpg
    L298StepperController.jpg
    what.jpg


    Duane, I used google pics to get images of the l298n. I just thought one or two of these could be printed out for you to draw on and explain while camera was rolling.
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  • ercoerco Posts: 20,256
    edited 2014-07-21 19:28
    This 298 board includes (at no extra charge) the very desirable and highly-prized "misaligned screw terminal" package!

    http://www.parallax.com/product/27112

    attachment.php?attachmentid=109720&d=1405996122
    400 x 320 - 69K
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-07-21 20:27
    erco wrote: »
    This 298 board includes (at no extra charge) the very desirable and highly-prized "misaligned screw terminal" package!

    That one looks down right tidy compared to some of the ones I received.

    I think Banana Robotics sells L298N boards like that one (though I'm sure their screw terminals are aligned). I've interacted with Nick who (I assume) runs the place and he seems like a nice guy. He was very quick to correct an error in his L298N article. It was a pleasant reminder most people are willing to accept they could have made a mistake and are anxious to correct it.

    That kid who calls himself "The Raspberry Pi Guy" has almost got me wishing I learned to properly curse. I find it difficult to express my amazement that someone so ignorant could be so arrogant. I better stop my rant (again) or I risk demonstrating my own ignorance. Oops, too late. That yucky tomato, pineapple! Anyone know a sailor who tutors?
  • ercoerco Posts: 20,256
    edited 2014-07-21 21:23
    Great site, that Banana!

    Wish I read that before I released the magic smoke on mine:

    Do not enable the onboard 5V regulator if you are supplying more than 16V to motors on pin 3 or the regulator will burn out.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-07-21 22:36
    Erco, do you think it could one day be a collectors item ?

    Ive just wiRED up the SN75441ONE, but nothing happened. I havent got time to look closly at whats wrong today, I have an assignmenrt due on the morals of fairy tales, I have some off beat interests ;)

    I cant figure for the life of me what moral there could possibly be in the Rapunzel Rapunzel , let your hair down fairy tale. Its just plain mean :)
  • ercoerco Posts: 20,256
    edited 2014-07-22 07:43
    It all becomes clear after you watch "Tangled" for the 1000th time with twin girls. :)
  • tommy7575tommy7575 Posts: 3
    edited 2014-08-07 04:23
    Hi Duane

    My question is Can I disable 5V regulator jumper and connect 5V on raspberry pi GPIO 2 to l298n logic 5V (and leave ENA and ENB jumpers ). Or you have a better idea?
    I use 4 x AA(1.5V)
    batterry for motors.
  • WhitWhit Posts: 4,191
    edited 2014-08-07 07:14
    @Duane - first of all thank you for the excellent video! I agree with those above who said that this clearly a labor of love.

    Secondly, thanks for the reminder that not every "expert" on the web or in a video is really an expert. It is amazing how many kind and smart people really do take the time to share and teach others what they know - but there are some folks who are not so careful or thoughtful. Let the user/maker take care!

    Thanks again!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-08-07 19:35
    tommy7575 wrote: »
    My question is Can I disable 5V regulator jumper and connect 5V on raspberry pi GPIO 2 to l298n logic 5V

    Technically pin #2 on the Raspbery Pi header isn't a GPIO. GPIO are general purpose input output pins. The GPIO pin # isn't the same as the pin number on the header so GPIO #4 is on pin #7.

    gpio-pinout-rev2.jpg
    Pin #2 is a 5V source. And yes, you could use it to power the logic portion of the L298N. But why? The only time I can think of when removing the jumper to the 5V regulator is a good idea is when you use a high voltage source to drive the motor and this high voltage is higher than the 5V regular can handle. I don't recall the exact figure for the upper limit for the regulator but I'm pretty sure it's above 14V.

    You have to connect some voltage source to the motor supply (labelled "battery +" in the photo in post #1). Why not let this same power source provide the 5V logic?
    tommy7575 wrote: »
    (and leave ENA and ENB jumpers )

    Whether or not the 5V regulator jumper in place has no bearing on whether or not you should use the jumpers on ENA and ENB.

    The problem with using jumpers on the enable pins (ENA and ENB) is in order to control the speed you need to pulse the "IN" pins.

    I discuss the issues with pulsing the IN pins in this post. Erco made a couple videos demonstrating the difference between pulsing the enable pins and pulsing the direction (IN) pins.

    tommy7575 wrote: »
    Or you have a better idea?

    Yes, I do have a better idea. Connect the L298N as shown in the video.

    If you want to save on GPIO pins and control the motor with two pins instead of four, you could add an inverter to the circuit so when one IN pin is high it forces the other one low and vice versa.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-08-07 19:59
    Thanks for the kind word Whit.
    Whit wrote: »
    It is amazing how many kind and smart people really do take the time to share and teach others what they know - but there are some folks who are not so careful or thoughtful. Let the user/maker take care!

    I'm also amazed at how generous people are with their time and are willing to spend time teaching strangers they've never met.

    Unfortunately some people's motivation is solely for self promotion. This kid calling himself Raspberry Pi Guy deletes any mention of his disastrous video and doesn't warn the possibly thousands of people who have boards wired incorrectly. Rather than admit his mistake he's willing to let these thousands of people burn out their boards in ignorance. IMO, this is incredibly cowardly and despicable behavior. I also think this behavior make it clear the kid calling himself The Raspberry Pi Guy is more concerned about his image of being an "expert" rather than really wanting to help people.

    Sorry about the rant Whit. This kid still boils my blood. I can tolerate arrogance from people who are really smart or talented, and ignorance is also easily tolerated, but the arrogance of the ignorant is hard to stomach.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-08-07 21:04
    but he did finally listen to you, though it was ten times more trouble than you should have had to go through. . He may be doing it for the money as well. I think you already told me that wasn't likely to be a factor. and I don't know how many thousands of viewers you need to make a dime but he does have advertisements so he must be trying ?
  • tommy7575tommy7575 Posts: 3
    edited 2014-08-08 05:17
    @Duane thank you for answering my question.

    Why not let this same power source provide the 5V logic?
    [FONT=Arial, Verdana, sans-serif]
    [/FONT] Will the regulator decrease voltage and will the motors get less voltage? Because I want to enable as much voltage as possible on the motors. I have baterry box 4 x AA(total 6V)
  • WhitWhit Posts: 4,191
    edited 2014-08-08 06:08
    @Duane - Thanks for trying to getting quality some info out there. I think the tact that most legitimate posters and companies take is that since you can't remove misinformation (posted by others) - you out-post with correct information (by you and your friends). You've got that process going.

    I have this version from Solarbotics - https://solarbotics.com/product/k_cmd/

    KCMD - IMG_8681.JPG
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