OCCRA
Go to Post Sometimes i wish the robot could fit into my pocket. - GMAdan [more]
Home
Go Back   Chief Delphi > CD-Media > White Papers
CD-Media  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

photos

papers

everything



Build your own PWM signal generator for testing motors and servos

WDB

By: WDB
New: 07-06-2018 11:13 AM
Updated: 07-06-2018 11:13 AM
Total downloads: 286 times


Instructions on how to build a PWM signal generator to test motors and servos. Relatively low-cost components make this project affordable and fun for the electrical team.

This project uses easy to find and affordable components to construct a Pulse Width Modulation signal generator that can be used to test motors and servos. The ability to bench test motors, subsystems, or prototypes without the need for RoboRIO or special software can save time. It is also a fun and and interesting project for the electrical team!

Attached Files

  • pdf Building a PWM signal generator

    Building a PWM signal generator.pdf

    downloaddownload file

    uploaded: 07-06-2018 11:13 AM
    filetype: pdf
    filesize: 2.8MB
    downloads: 284



Recent Downloaders

Discussion

view entire thread

Reply

07-09-2018 12:26 PM

lynca


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Thanks for sharing !



07-09-2018 03:53 PM

asid61


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

This looks very interesting, but you might be better served buying a standard RC PWM generator for a couple dollars, or at least sourcing components from places like Ebay or Aliexpress to save on costs.
I do like the addition of a small battery though, very useful to have that on there! Definitely beats powering it from an Anderson connector.



07-09-2018 04:31 PM

gerthworm


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Yes, thanks for providing info on this!

One minor question:

Quote:
This is the program used for our device. Itís not perfect, nor is it intended to be.
Looks like clean code to me! Why not strive for greatness?



07-09-2018 05:46 PM

s-neff


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by asid61 View Post
buying a standard RC PWM generator
Can you be more specific, like a buy link? I can't find the component or board you're talking about.

I did find a forum of EEs talking about hacking something together out of a set of 555's, but that's way harder for me to do than program a cheap microcontroller.



07-09-2018 05:59 PM

AriMB


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by s-neff View Post
Can you be more specific, like a buy link? I can't find the component or board you're talking about.

I did find a forum of EEs talking about hacking something together out of a set of 555's, but that's way harder for me to do than program a cheap microcontroller.
If you google "Servo Tester" you'll find a lot of different options for cheap (less than $10). I've used a generic one (don't remember where I got it from), and it worked pretty much as expected with PWM motor controllers. If you can find it on CD, I think Ether posted something about one that he recommended a year or two ago.



07-10-2018 11:05 AM

dwfunk4475


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by asid61 View Post
This looks very interesting, but you might be better served buying a standard RC PWM generator for a couple dollars, or at least sourcing components from places like Ebay or Aliexpress to save on costs.
Why does there always have to be a Negative Nellie every time someone presents a cool unique solution to a problem that they have.

It would have been extremely prudent to have actually read the document and just maybe one would have found this statement:

Quote:
Building a DIY PWM driver also offered a great opportunity for the electrical team to gain a little more experience in designing a functional solution, sourcing quality components, programming a microcontroller, and some human-machine interface development experience.
FIRST is all about technology, learning, applying what's been learned.



07-10-2018 01:03 PM

asid61


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by dwfunk4475 View Post
Why does there always have to be a Negative Nellie every time someone presents a cool unique solution to a problem that they have.

It would have been extremely prudent to have actually read the document and just maybe one would have found this statement:



FIRST is all about technology, learning, applying what's been learned.
I did read through the document, and I liked what I saw. I wanted to implement it on our team for electrical trainings (we have been looking for "fun projects" for a while now) and so I liked the look of this. But a $50 price tag is too high to spend on trainings for just a couple of people.
If you look through my old images, you'll see that I've built a DIY PWM generator for FRC before, and I know what these things can cost. There's no harm in swapping out some of the pricier components for cheaper alternatives.



07-10-2018 01:39 PM

s-neff


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by AriMB View Post
Search term
Quote:
Originally Posted by asid61 View Post
Links
Thank you!!

I've been thinking about building OP's box for a couple years, but had never found those devices before - the power of the right search term!

Quote:
Originally Posted by dwfunk4475 View Post
Why does there always have to be a Negative Nellie
Whoa slow your roll buddy - suggestions of improvements are a sign of respect around these parts.



07-11-2018 11:11 AM

dwfunk4475


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by asid61 View Post
I did read through the document, and I liked what I saw. I wanted to implement it on our team for electrical trainings (we have been looking for "fun projects" for a while now) and so I liked the look of this. But a $50 price tag is too high to spend on trainings for just a couple of people.
If you look through my old images, you'll see that I've built a DIY PWM generator for FRC before, and I know what these things can cost. There's no harm in swapping out some of the pricier components for cheaper alternatives.

Wow! $50 is too much for training a "couple" of people?? So sad!

I feel real bad for your students.

SMH!



07-11-2018 11:34 AM

dwfunk4475


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by s-neff View Post
Thank you!!
Whoa slow your roll buddy - suggestions of improvements are a sign of respect around these parts.
Improvement?? Respect?? You've got to be kidding!

Anytime there is a "but" it's all negative from there no matter what else is tacked on as an alleged suggestion for improvement.

Once you've tossed in a "but," you've shot down the idea, caused dismay that the idea is unworthy and anything further stated in the message isn't received. Furthermore, a "but" does not convey respect. It conveys a "you are lacking" message.

Being a cheapskate and always looking for the cheap way out does not teach anything useful nor anything productive.

They came up with a plan, it had a purpose, they obviously can afford it, they were not looking for cheaper alternatives and y'all immediately stomped on their project. That is NOT respect!

Education, knowledge costs time and money to acquire. The less you have of one, the more you need of the other.



07-11-2018 12:11 PM

Nate Laverdure


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by dwfunk4475 View Post
They came up with a plan, it had a purpose, they obviously can afford it, they were not looking for cheaper alternatives and y'all immediately stomped on their project. That is NOT respect!
Thanks for your interest, but we don't see it that way. One of our most valuable assets is the feedback and criticism we actively solicit... Lessons learned are treasure to an effective iterative development effort. Please don't stand in the way of our learning.



07-11-2018 01:47 PM

Marcus Q


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by dwfunk4475 View Post
Improvement?? Respect?? You've got to be kidding!

Anytime there is a "but" it's all negative from there no matter what else is tacked on as an alleged suggestion for improvement.

Once you've tossed in a "but," you've shot down the idea, caused dismay that the idea is unworthy and anything further stated in the message isn't received. Furthermore, a "but" does not convey respect. It conveys a "you are lacking" message.

Being a cheapskate and always looking for the cheap way out does not teach anything useful nor anything productive.

They came up with a plan, it had a purpose, they obviously can afford it, they were not looking for cheaper alternatives and y'all immediately stomped on their project. That is NOT respect!

Education, knowledge costs time and money to acquire. The less you have of one, the more you need of the other.
Your right, too many teams these days are going the cheap and easy way out and sacrificing the learning experience of students. That's why we have our students mine all the raw bauxite and then refine it, smelt it and extrude it into aluminium box tube. We don't need no fancy vex pro pre-drilled stuff. Our students get the knowledge they need in the real world.



07-11-2018 02:02 PM

marshall


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by mman1506 View Post
Your right, too many teams these days are going the cheap and easy way out and sacrificing the learning experience of students. That's why we have our students mine all the raw bauxite and then refine it, smelt it and extrude it into aluminium box tube. We don't need no fancy vex pro pre-drilled stuff. Our students get the knowledge they need in the real world.
Serious question, how do you account for that on the CAW? We've got some trees that were planted by students and they are big enough now that we have been debating using them for bumper wood but we're not sure how to account for the CAWst. Is it just the price of the seed or sapling? Do you think we need to include the cost of the full packet of seed or just the per seed cost, which I think is less than $5? I'm not sure.



07-11-2018 02:39 PM

GeeTwo


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by mman1506 View Post
Your right, too many teams these days are going the cheap and easy way out and sacrificing the learning experience of students. That's why we have our students mine all the raw bauxite and then refine it, smelt it and extrude it into aluminium box tube. We don't need no fancy vex pro pre-drilled stuff. Our students get the knowledge they need in the real world.
Quote:
Originally Posted by marshall View Post
Serious question, how do you account for that on the CAW?
Buying enough land for a bauxite mine for under $4k sounds tight, unless they're a sponsor.

R14 must be a real bear as well.



07-11-2018 02:46 PM

Marcus Q


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by marshall View Post
Serious question, how do you account for that on the CAW? We've got some trees that were planted by students and they are big enough now that we have been debating using them for bumper wood but we're not sure how to account for the CAWst. Is it just the price of the seed or sapling? Do you think we need to include the cost of the full packet of seed or just the per seed cost, which I think is less than $5? I'm not sure.
Depends, is the sun a mentor and/or sponsor?



07-11-2018 02:56 PM

marshall


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by mman1506 View Post
Depends, is the sun a mentor and/or sponsor?
Sol is registered as a sponsor.

Quote:
Originally Posted by GeeTwo View Post
Buying enough land for a bauxite mine for under $4k sounds tight, unless they're a sponsor.

R14 must be a real bear as well.
I'm not sure we account for our rent on the space we're in now... hmm...



07-11-2018 03:12 PM

notmattlythgoe


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by dwfunk4475 View Post
Anytime there is a "but" it's all negative from there no matter what else is tacked on as an alleged suggestion for improvement.
This is a nice post, but I like your shirt.



07-11-2018 03:22 PM

s-neff


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by notmattlythgoe View Post
This is a nice post, but I like your shirt.



07-11-2018 04:07 PM

CarlosGJ


Unread Re: paper: Build your own PWM signal generator for testing motors and servos

Quote:
Originally Posted by GeeTwo View Post
R14 must be a real bear as well.
Arguable, given the definition of "fabricated":
Quote:
Note that it is possible for an item (typically raw materials) to be neither COTS nor a FABRICATED ITEM. For example, a 20 ft. length of aluminum which has been cut into 5 ft. (~152 cm) pieces by the Team for storage or transport is neither COTS (itís not in the state received from the VENDOR), nor a FABRICATED ITEM (the cuts were not made to advance the part towards its final form on the ROBOT).
I think you could mine, crush, refine, and cast the aluminum into ingots in the offseason, as long as you don't start casting or extruding it into useful shapes before kickoff.



view entire thread

Reply

Tags

loading ...



All times are GMT -5. The time now is 12:52 AM.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin®
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi