Using load cell to control motor speed/thrust

Using Arduino Project Guidance
1

I was wondering if you were able to use load cells, along with amplifiers for analog to digital conversion, to control the speed(and therefore thrust) of a motor?

Essentially am I able to replace a potentiometer with a load cell and amplifier. So the higher the load the more voltage supplied by PWM, but the lower the load the lower the voltage supplied by PWM

3

What are You talking about?
Please read this link and get an idea what helpers in forum expects from You: How to get the best out of this forum - Using Arduino / Project Guidance - Arduino Forum

1 Like
4

Oh okay, I think I may have posted in the wrong forum.

5

no. but speed and thrust are not the same. However a load cell will do a good job of measuring thrust.

6

The Op wants to monitor the thrust and adjust the speed (of I imagine a motor driven propeller)to maintain a degree of thrust, clear to me.

7

Yes thatā€™s correct! So in my view thatā€™s comparable to how you are able to control the speed of the motor via a knob of a potentiometer. However I am wondering if that is a fair comparison and if I am able to go through with this load cell method?

8

Yes Iā€™m aware of speed and thrust not being the same thing, my bad I shouldā€™ve clarified a bit more. I meant as in if Iā€™m able to use the load cell and amplifier to control the speed of the motor, through PWM(like how a potentiometer does).
As the speed of the motor does affect the thrust of the motor, the slower it turns the less thrust it produces, I thought to have included them similarly in my original post.

9

Hi,
Google;

YouTube measuring propeller thrust Arduino

It has been done many times before, these may help.

Tom... :smiley: :+1: :coffee: :australia:

10

Would I be able to change the speed of the motor by changing the load on the load cell(and amplifier). Like is it possible to directly control the speed of a dc motor through varying the load on a load cell, similar to how you can directly control the speed of a motor with a potentiometer

11

Measure load on the load cell and then use it as the arg2 of the following function to generate PWM signal.

analogWrite(DPin, arg2);

For valid DPins, see Fig-1.
pwm328x
Figure-1:

12

Everyone but @GolamMostafa seems stuck on the idea that the thrust of the motor is to be sensed by the load cell or otherwise entering into what the pot once did.

As I read your original post, my thought was what you said, just replace a potentiometer that does a job now with a load cell.

Amirite?

Please clarify and save us some time.

If you literally want only to replace the pot as that part that figures out and informs the motor speed or thrust, doing will be independent and separable, and the solution of @GolamMostafa is exactly what you need.

If on the other hand all the crystal ball gazing going on has actually identified a more subtle idea, that the load cell has anything at all to do with what the motor ends up doing (other than its speed!) then please a few details about how this is envisioned mechanically.

a7

13

Yes you are right. I just wanted to know if Iā€™m able to replace the job of a potentiometer with a load cell.

So the varying load on a load cell can affect the speed of the motor, similar to how the potentiometer can affect speed of motor when you turn the knob

14

Your other topic on the same subject deleted.

Please do not duplicate your questions as doing so wastes the time and effort of the volunteers trying to help you as they are then answering the same thing in different places.

Repeated duplicate posting could result in a temporary or permanent ban from the forum.

It will help you get the best out of the forum in the future.

  • Your OS and version can be valuable information, please include it along with extra security you are using.
  • Always list the version of the IDE you are using and the board version if applicable.
  • Use quote or add error messages as an attachment NOT a picture.
  • How to insert an image into your post. ( Thanks @sterretje )
  • Add your sketch where applicable but please use CODE TAGS ( </> )
  • Add a SCHEMATIC were needed even if it is hand drawn
  • Add working links to any specific hardware as needed (NOT links to similar items)
  • Remember that the people trying to help cannot see your problem so give as much information as you can

COMMON ISSUES

  • Ensure you have FULLY inserted the USB cables.
  • Check you have a COMMON GROUND where required. ( Thanks @Perry)
  • Where possible use USB 2.0 ports or a USB 2.0 POWERED HUB to rule out USB 3.0 issues.
  • Try other computers where possible.
  • Try other USB leads where possible.
  • You may not have the correct driver installed. CH340/341 or CP2102 or FT232 VCP Drivers - FTDI
  • There may be a problem with the board check or remove your wiring first.
  • Remove any items connected to pins 0 and 1.

COMPUTER RELATED

  • Close any other serial programs before opening the IDE.
  • Ensure you turn off any additional security / antivirus just to test.
  • There may be a problem with the PC try RESTARTING it.
  • You may be selecting the wrong COM port.
  • Avoid cloud/network based installations where possible OR ensure your Network/Cloud software is RUNNING.
  • Clear your browsers CACHE.
  • Close the IDE before using any other serial programs.
  • Preferably install IDEā€™s as ADMINISTRATOR or your OS equivalent

ARDUINO SPECIFIC BOARDS

  • CH340/341 based clones do not report useful information to the ā€œget board infoā€ button.
  • NANO (Old Types) some require you to use the OLD BOOTLOADER option.
  • NANO (ALL Types) See the specific sections lower in the forum.
  • NANO (NEW Types) Install your board COREā€™s.
  • Unless using EXTERNAL PROGRAMMERS please leave the IDE selection at default ā€œAVRISP mkIIā€.
  • Boards using a MICRO usb connector need a cable that is both DATA and CHARGE. Many are CHARGE ONLY.

CREATE editor install locations.

  • On macOs ~/Applications/ArduinoCreateAgent-1.1/ArduinoCreateAgent.app/Contents/MacOS/config.ini
  • On Linux ~/ArduinoCreateAgent-1.1/config.ini
  • On Windows C:\Users[your user]\AppData\Roaming\ArduinoCreateAgent-1.1

Performing the above actions may help resolve your problem without further help.
Language problem ?
Try a language closer to your native language:

Thanks to all those who helped and added to this list.

Thank you.

15

Hi,
You may still need the pot to set the thrust level you want the motor to maintain, in other words the setpoint of your system.

Tom... :smiley: :+1: :coffee: :australia:

16

THX.

Of course you can. See @GolamMostafa for an idea of howā€¦ and keep in mind that in software, you can usually replace/modify/swap "components" that you use to build something, as long as you pay a little attention to keeping things separate to begin with.

So here, just get the load sensor to produce the same value that you obtained from the potentiometer, then use that value in the identical fashion to control the morot.

If you could code getting a number from a ham sandwich, you could use a ham sandwich to do, well, whatever.

Hmm, ham sandwich. :wink:

a7

17

Ah okay, thank you for letting me know! Sorry for any disturbances

18

Haha that is true! So all Iā€™d have to do is just simply replace the ā€˜PotValueā€™ variable with a ā€˜LoadValueā€™ with values from the load sensor(rather than a potentiometer), and then continue from then on as Iā€™d normally do with a potentiometer to control motor speed? Thank you so far for the help :slight_smile:

19

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.