Turn any DC Motor into a Servo Motor
ฝัง
- เผยแพร่เมื่อ 4 พ.ค. 2024
- You can sign up for the Free version of Onshape here: Onshape.pro/HowToMechatronics
View and download the 3D model: bit.ly/customservo
I ordered the PCB from PCBWay: www.pcbway.com/?from=HowToMec...
STL files, parts list and more details ► howtomechatronics.com/project...
If you enjoy and find the content that I make useful, please consider supporting me on Patreon: / howtomechatronics
You can order the PCB from PCBWay project sharing community: www.pcbway.com/project/sharep...
Parts list (check website article for full list, affiliate links):
Amazon.com:
DC Motor 12V: amzn.to/3g6ax9X
AS5600 encoder: amzn.to/45egj0D
DRV8871 driver: amzn.to/46jxNdG
FLYSKY RC Transmitter: amzn.to/2RibIdZ
AliExpress
DC Motor 12V: alii.pub/6shvt2
AS5600 encoder: alii.pub/6shvsa
DRV8871 driver: alii.pub/6shwgs
FLYSKY RC Transmitter: alii.pub/5tc9ft
In this video we will learn how to turn any DC motor into a stand-alone servo motor with a lot of features. Unlike regular servos that have limited motion of 180 or 270 degrees, this one has unlimited range of 360 degrees and in addition to that we have the ability to adjust the range of the rotation to whatever value we need. We can also set a custom center point, we can adjust the responsiveness, it has continuous rotation mode and it can be controlled through an analog input, digital input from a RC receiver and using the serial monitor from our PC.
00:00 Overview
04:18 How a Servo Motor Works
05:08 Closed-loop System
06:50 AS5600 Encoder
08:33 Circuit Diagram
10:59 PCB Design
13:09 3D Design - Gearbox
14:45 Assembling the Servo
17:36 Bootloader and Programming the Servo
19:28 Test
22:18 Code
24:37 Outro
Visit HowToMechatronics.com for more Tutorials, Tips, Projects and How It Works videos:
► howtomechatronics.com/
Like my page on Facebook:
► / howtomechatronics - วิทยาศาสตร์และเทคโนโลยี
![How to make a REAL servo out of any motor. Multi-loop control. A robot dog? [Diary of a Madman №5]](http://i.ytimg.com/vi/yFH8key-t_M/mqdefault.jpg)
Check out my favorite 3D printers, the K1 Max: amzn.to/3txQUC6 or if you are on a budget, the Ender-3 V3 SE: amzn.to/3FkCPus
I hope you enjoyed this video and learned something new! If you'd like to support me making more content like this, please consider supporting me on Patreon: www.patreon.com/howtomechatronics
I have done a lot of soldering of small components and if you don't want to go the whole paste mask route I suggest you get some 0.35mm solder instead of the 0.56 or 0.71 which you are using, it dramatically reduces blobs and bridging. Also for soldering QFN's and SOIC's it's advisable to use a no clean gel Flux, I use Multi-core BGA flux but there are others.
I also like to use a low temperature solder (~180C). as it flows much nicer and reduces risk of thermal damage if you have to do rework.
I have a hall effect encoder, IBT_2 motor driver, Arduino Uno and flysky transmitter receiver. I want to run brushed dc power window motor as servo type. how to get arduino code for this
The PID needs work. It overshoots a lot.
I was thinking that too. It should definitely not be overshooting that much with such slow movement. The whole point of a servo like this is having fast movement with positional accuracy. Considering he's using a multiturn encoder it might even be smarter measuring the angle of the motor shaft before the gear reduction. That might add some mechanical challenges of where to place the PCB though.
@@enteente6027Measuring the motor shaft angle will make it lose the ability to measure the absolute position of the output shaft, also losing the ability to compensate for play in the gears
@@nrdesign1991no, you will still know the absolute position of the output shaft since you know the gear ratio, as he is using a multiturn encoder. Play in the gears can also not be compensated either way, because even when measuring the output shaft there's nothing the motor can do about it
Yep, that's right. I will leave that for another tutorial I guess.
Cheers! :)
Yeah, was thinking the same. Perfect shield though!
You are doing a great job for the community. Thank you for these informative videos. You’re amazing
Happy to hear it, thank you!
I wish TH-cam had an option to give 5XThumb ups. You sir, certainly deserve 5X👍
I like the gears. I've never seen that herringbone geometry before.
I research on this so long ago, I think u are first one get on this topic thanks alot. I waited so long.
Glad to hear it!
Great video as always! You are my inspiration, man.
Great work, wanted to build this for a while, saved me a lot of time
Great to hear!
Ingenious. I have a need for something like this.....soon as I finish your RC transmitter project, that is.
Thank you!
As always another high quality work. Thank You. I hope you will make a self balancing bicycle with reaction wheel one day.
Thank you!
Having an option to use Encoder separately (on a daughter board) will be great addition!
What's it like to actually complete a project that works? I've always wondered lol. Very nice design!! Thanks for sharing.
Terrific job! Outstanding description....thanks for sharing your design
Glad to hear it, thank you!
Very nice project. I will try out but only issue is that i lack 3d print design.
Cheers !!
I recommend using a switching power regulator instead of a linear one. Reason is that the voltage doesn’t have to be super precise and switching regulators don’t waste the power from converting 12 V to 5 V.
I tried using one of those small voltage changing switching pwr supply, loses notable current. Perhaps a larger pwr. supply located elsewhere would provide enough amps if you go that route.
@@2150dalekwell yeah your only converting the voltage not the amprage :)
I don't see that as a big problem here. The only notable devices using 5 V are the atmega, as5600 and the led. I asume all these components together draw less than 10 mA (atmega is 0.5 mA, as5600 is 6.5 mA). The voltage difference is 12V - 5V = 7V and 7V * 0.01 A = 70 mW of power wasted. This is nothing compared to what the motor uses.
@@enteente6027 yes you are right, I didn’t see that the motor gets 12 V in the first place. Thought it gets also 5 V.
@@enteente6027 The ATmega328P will use more power than just 0.5mA.
It's an amazin project. Thanks a lot for share your study
Glad to hear it, thanks!
Thank you, this is an outstanding project. I'm adding it to my build list. It looked like the servo is overshooting the position somewhat. I saw a feature you may want to consider researching and/or implementing. I think it was James Bruton who programmed the controller to half the remaining rotational distance and go there, half it again, half it again.... That would allow the servo to ramp down and stop the servo at a more precise point.
a PID would be better but that would take a bit more of your MCU
Great video and interesting idea. One thing i would add though is two header pins that can be used as external reference inputs or endsrops for driving things like a linear axis
Thanks! Yeah, that's a good point.
I've been thinking about it right now, to make an linear actuator with the same PCB. I mean, the board already has digital pins available, the SPI pins, MOSI, MISO and SCK, which are used only for burning the bootloader, so we can use those as digital inputs.
@@HowToMechatronicsIt seems you did much more than just some thinking. I really liked your design for a 3d printed linear actuator. I used to work as a test engineer for linear actuators and I probably couldn't habe done it much better myself.
One comment about your PCB: for IC connections, the pad for pin 1 should have a different shape than the pads for the other pins. Usually, pad 1 is square and the other pads are rounded.
great project. a tip for your soldering, bring the solder in first and use it to transfer the heat to the board 😉
Thanks! I'm trying. :)
The way to solder microcontroller pins is not one by one, but add a decent amount of soldering tin basically soaking multiple legs by keeping the tin liquid, tilt the board to use the gravity and just pull the soldering iron slowly, it will attract the tin and leave just enough tin on the pins. I usually start soldering the microcontrollers to my boards and then the smaller parts. Nice project as usual! Thank you for sharing!
I just tap the board to the table so the solder falls off..thats how i managed to remove a big short when i was soldering a new nand flash for my router
Thank you!
Please which software do you use to draw the pcb and 3d redering.
Which software did you use to design the circuit diagram
Great video, could you make a tutorial Video on Arduino cnc shield?
Most Impressive, Thank you
Many thanks!
Very nice presentation! For future servo discussions, can you indicate the torque you were able to achieve with the home build?
Very useful video, thanks
Good job friend 🤩
Really amazing video ❤
Neat project. It would be interesting to pair that Hall sensor with a wireless controller like an ESP32 in case your "output" is actually physically pretty far away from the drive section.
Next time try knife type K type soldering head for the best results. You can solder better with these. I soldered most of the smd by hand and been doing that for over 15 years and never had a problem also temperature is important, hakko inline temperature control works best too. Cheers
What tool was used to make the circuit diagram? It’s very nice!
Interesting project, please tell me the values of subrack resistors and the possibility of using a more powerful module to control the motor, for example IBT-2 or BTS 7960
Excellent work!!! Thank you for your valuable information. What gear (camera, lens) do you use? I need something similar for my lectures.
Excellent explanation. Here, take my subscription.
very interesting project and well done.
Thank you! Cheers!
very useful, thanks
Glad to hear that!
Can you fit all that on a 8 pin tiny? The 5th pin can be fused for use in logic. I cant imagine youd need more than 5 pins on that 328p.
Great work Dude :)
That's pretty damn cool.
Thanks!
What an amazing video! Are you planning to use this custom servo in another project?
If you plan to use this on a battery powered device, I would steer clear of linear regulators like the AMS1117, and instead opt for an equivalent switching regulator.
Awesome video!
very well done
Awesome stuff. I am a copier tech and there are ready to go gearboxes with DC that just need your circuit. I have made DC servos using photo interrupters but not close to 4096 accuracy. Great content! Did you use onshape for the PCB design?
Plz make video demonstrating mpu9250 and calculating ots roll witch and yaw from accelerometer, gyroscope and magnetometer
That's a superb video, great job ! I was wondering how do you make your schematics ?
Thank you! I draw the schematics manually with Illustrator.
Super informative video ... thank you.
Personally, I'd have made a couple of changes:
1. My opinion: the 328p has been over-hyped because of the Arduino community, but by today's standards it has some issues, so I'd use something else. Being 8 bits is probably not an issue here, but it's more expensive than 32 bit alternatives, such as the CH32V003 or the ESP32-C3. Besides this, Atmel(Microchip) debuggers are 'really' expensive and the 328p is very easy to brick. Even one of the newer ATTiny chips would be a better choice.
2. I had an issue with pcbway, so I much prefer JLCPCB. They are very reliable, high quality and probably cheaper anyway. They just don't advertise as much.
Otherwise, Great project ... looking forward to more.
The 328P not 'hyped' as much as it is easy to leverage a ton of available code and support. I put it in a lot of my commercial designs, not because it is amazing, but rather because it is easy. I have a lot of code ready to go so firmware dev cycles are short and the final performance is easy to predict.
Awesome video! Consider using a lot more of "external" flux while soldering those SMD components ;)
Thanks for the input!
Great video
Thanks
on pins 5 and 6 in the ckt diag at 8:39 , won't Atmega328p require pull up resistors from drv8871 as they are signal pin? I mean i have started learning hardware for my line tracer bot, and wanted to build my own pcb, this ckt diagram looked helpful for my whole motordriver, thats why am asking.. any help is appreciated.
Great job! Is the center position permanently stored even without power supply?
Thanks! Well the default center position is always the same, even after power loss because it depends on the magnet orientation. However those new center positions that we can set with the push button are not stored, they are lost with power loss. However, that can be easily solved, we can store last center position value in the EEPROM of the microcontroller.
can you show a closed loop diagram with feedback?
Curious if you have tested the torque of this new servo. Are the gears PETG or PLA? Great video. Hoping you make a video creating a servo (close loop positional) BLDC 3 phase motors used in drones and hoverboards!! Seems that is what they use for a lot of robots axis these days.
Impressive ! Awesome ! Great !
Thank you!
This is an engineering marvel. @howtomechatronics... question... how do you "home" this servo? Do you need an endstop? I'm asking on the continuous rotation mode. I would need to use them on a Sailboat, and a multiturn potentiometer (near ˜10 turns from end to end) is not an option (humidity environment).
Thanks!
Well yeah, you need to have an end stop for homing for making use of the continuous rotation mode.
Are we able to connect & control multi servo motors simultaneously with different IP address?
Is the code somewhere posted?
I loved
I have the boards I ordered from PCBway (a great company BTW) and am getting the components together. A few things though, can you provide a more complete schematic that corresponds to the component numbers on the PCB? I am having to reverse engineer the board to match all of the capacitor and resistor values with the diagram provided, and it is very time consuming and can lead to mistakes.
Also, there are many components that you don't source (i.e. center select button, chip resistors with sizing, SMD electrolytic capacitor, etc.)
I had to research the chip resistors and found they were 0805 resistors, which would have been nice to know beforehand, as I already had 0402's on hand and thought they would work before I received the boards.
Anyway, other than that I love this project and am looking forward to working on it.
OMG!!! I want to do this with a Crown Vic or Chevy Malibu window/ wiper Motor.
Where to give the inputs of step & direction in this circuit for CNC machine
Odd question but could you add a how to on converting the scara robot arm into a 3d printing robot arm, I always see space x and all the big time manufactures of heavy machinery always using 3d printers that are usually arm mounted for a larger project, and I know they use direct metal printing but I would love a how to just to understand it a little better
Clean that soldering iron tip!! It will make your work much easier :)
Thanks for the iron tip tip! :)
The servomotor knows it's current position at all times...
We need to read real time temperature on the remote control then order the motor move to adjust speed of blower by the remote control ,can you?
Why the huge overshoot? Have you seen openServo?
Good job!
Thanks!
Can you share project details
Can this board be made to use potentiometers tho? I rehab robot toys and the vast majority of the motors used are DC servos but unlike hobby servos, the controller circuitry is on the often broken main board. so i have 3 potentiometer wires and 2 motor wires and rather than take apart good hobby servos and use their boards for this, i want to make a drop in replacement thats like the boards in servos. can your circuit support potentiometers rather than magnetic encoder?
When soldering SMD components, tin only a single pad and solder the device to it. Then the other pads can then be soldered while the IC is being held in the right position by the first connection. DON'T tin multiple pads, as the bumps of tin will prevent correct positioning of the device.
I wonder how easy it would be to code an auto calibration routine, where the motor spins up as fast as at it can, stops as quickly as it can, and measures the overshoot to calibrate the PID values? Have a button that you have to hold down and power the device up to run the calibration :D
So many possibilities with this. Even adding an option for BLDC motors. This is a great video :D
Yeah, there are so many possibilities. Thanks! :)
Which program do you use to draw schematic at 8:34
Why haven't you tuned the PID loop?
You have either too much I or not enough D.
Nice project, thanks for sharing!
Already spent too much time making this project, so I left that for those who will build this project. Cheers :)
Would this drive a treadmill motor? They are 12 volts. I don't know about the amperage.
This is a fun project, but I thought the AS5600 was supposed to be pretty good, within 1deg, looks like you're getting a ton of slop, 5-10deg in your position control?
What are the benefits and tradeoffs of such a project as opposed to simply buying a servo with the features you desire? Wouldn't this burn out the DC motor if you use it to rapidly swing back and forth?
Do you sell completed units?
good work !, i try to order pcb and the web detect a 4 layers , but is a 2 layers . where i can download the firmware? , don't see the link in description. thanks
Thanks! The PCB is 4 layers. The middle layers are for GND. The source code will be available in couple of days on the website article.
Getting an perfectly symmetrical magnet and mounting it perfectly over the shadt center isn't trivial.
can you pleas make a proper flight controller for drone
I think you just need a smaller soldering iron tip and you would have no problem with these smaller components.
Good
It would be cool if it were possible to use the bldc motor.
Fantastic video! May I ask what field of engineering you went to school for or if you went to school?
Thank you! Mechatronics, of course. Cheers :)
Can this pcb with components available
Why not use a common microcontroller like ESP32?
Then the PCB design is now good to go? With no problems?
Хороший драйвер получился. Я взял ASMC- 04 драйвер и модуль AS5600, хочу заменить родной потенциометр магнитным as5600.
Шестерни каким пластиком печатали?
Where is the schematic showing components and values? Where is the detailed parts list?
The servo in the video has quite a bit of overshoot. But that's just a matter of PID tuning
R4,R5 How much resistance is there?
I have noticed you don't answer any of the questions supporter post????
Hello, is the Arduino code up on your website? I didn't see it there.
Yes it's up there now.
Cheers
@@HowToMechatronics Thx!
you may try other control methods, maybe the overshot can be avoided
It has some backslash ... goest to set deg, passes it, then back a little....
Next upgrade - use bldc motor 💚
That would be interesting!
Thanks for the info, what drawing software do you use?
A big problem with this design is that it needs homing every time you use it. If power is lost, you lose the home position. Even if you know the output shaft location, that isn't helpful because it is not constrained to a single turn. Commercial servos like this use a backup battery, so that the position is not lost during power off.
What about absolute encoder?
You need homing for the continuous rotation mode, that's right. But for the limited rotation mode, up to 360 degrees, you don't need homing. The AS5600 is like an absolute encoder. It reads the magnetic field orientation of the magnet on the output shaft.
❤