Grounding yourself w/ a suitable ESD wristband without a PSU

So I do not own a laptop or any personal computer as I have no need for either of them (until I get deeper into electronic tinkering with an Arduino, etc). I do have an ESD wristband that I bought from a local computer store that has an alligator clip on the end. I've done a bit a research, but only getting mixed answers as to how I can ground myself without a PSU. I'd like to guarantee that I don't fry any of the beginner electronic projects that I plan on doing. How exactly am I supposed to ground myself with an ESD-wristband? I do own rubber Nike sandals (open-toe) that I don't mind wearing to help avoid frying any electronics, have a wooden surface on my workbench, but my workstation area is all on carpet. Thanks in advance!

Topic by TXVisual   |  last reply

Dir-300 as Wifi repeater

Hello, I have an AP in my house which broadcasts our wireless Internet signal throughout our house. Unfortunately there is a spot in my house where the signal is not received. I have a spare dlink dir-300 router which I installed custom firmware on (dd wrt). Can someone please help me use it as a wireless repeater. I want it to boost the signal of my other router. Dd wrt has a repeater function, but my router is an atheros chipset so it is not native on my device. P.s: I don't really want some cheap wifi booster made of tinfoil :p . Thanks in advance, Sam

Topic by Bituser   |  last reply

Is this a CC Licensing violation?

I came across a blog that shared my DIY rotary tool project which is under CC-BY-NC-SA.  I am new to this licensing thing, but how the project has been shared by the blog doesn't feel right to me.  The blog admin has downloaded the images and stl files from my instructable and uploaded directly to their website and in the 'parts required' list they have put affiliate links. Does it violate the Non-Commercial license?  At the end of the article, they have a small link to my instructable.  Is this legal to do so and within the limits of the Creative Common license? If yes, What can I do in the future so that other people are not using my projects for making easy money? Thanks. 

Topic by Makernaut   |  last reply

Instructables in the Classroom

Just wanted to let all know that we have a group of students involved with  I gave my students a simple project...Make something and document it.  Please take a look at the projects that have been posted so far.  I only post when I feel it meets guidelines of a contest.   Also try to incorporate the value of social media other than posting picts on Instagram Check us out and follow MyWlakeTech Was just notified that one of my student's projects made it as a Finalist in the FIRE Challenge. Looking forward to any feedback other teachers might have.  Really proud of all the FEATURED projects they have created. Regards, MyWlakeTech

Topic by MyWlakeTech   |  last reply

Lost the ability to modify photos

Hi guys, I have lost the ability to modify a pic once uploaded on the website... B

Topic by BaptisteL8   |  last reply

Super basic resource for learning electric motors

I watch an insane amount of YouTube, particularly woodworking, as designing and building furniture is my big passion in life. I have, however, become more and more interested in learning about motors. It has become increasingly obvious to me that literally, every tool in a workshop is simply a motor that turns something. Saws, drills, sanders, planers, jointers, even dust collectors are all nothing more than a motor turning something around and around in a circle.   I just bought a new Table Saw, and during my 6 months of researching, I read all about 1, 2, 3, and even 5 horsepower motors. Single-phase vs. three phase. rpms, 110V vs 120V vs 220 vs 240V etc etc etc... It was all mostly abstract, as I could tell that higher horsepower means "good" and lower horsepower means "less good." But now, I have a lot of projects that I want to build, but I know nothing about motors.  I've been watching a lot of Matthias Wandel on YouTube, and I want to know everything there is to know about motors. Unfortunately, I don't know anything really about electronics at all. But I feel like learning about motors is a great place to start learning. Does anyone have a book or a resource that literally takes things back to motors 101 for 10 year olds?

Topic by Dolmetscher007 

Hydroelectric Generator

This is my first topic, so I need your opinion - is this possible? I have all of these items.

Topic by AdvanŽ   |  last reply

HP iPAQ - what can I do with it?

I've got an HP Ipaq HX2100 gathering dust - I used to use it for reading ebooks on, but now use my blackberry. I was going to put it on ebay, but it wont sell for much, so I'm looking for idea's for what I could use it for. Doesn't have wifi on it so it kinda limits the options I suppose. Any idea's? Cheers, Pha3dr0n

Topic by pha3dr0n   |  last reply

knex pocket pistol

This is my knew knex pocket pistol, it can fit in a pocket (obviously) and is very powerful here is the link for the instructable

Topic by dynamite_kid   |  last reply

How to make a mold

Hi there! :) In a couple of weeks I'll receive my first 3D printing! I'm so excited about it! One of my first projects I would print is a Flower Pot and... I'd also like to print a mold of this Flower Pot but I have a question: > First check the image of the Flower Pot dsign< How should be the design of the mold to allow me to make a new models with concrete (cement). I don't know how to solve the holes. Look, if I do with two external parts and one internal part... how can I do the holes and after take out the mold? I will think more about it but, if you have any idea... it's going to be great read it!! Thanks a lot!! =)

Topic by Kitus87   |  last reply in the Classroom

Hello All, I have been in the Instructables community for the past 9 months on a personal account.  I currently teach computer technology to grades 5 and 6.  I had a thought that this community could be a great resource for my students to look for information and also share. My question to the community is this.  Is there a designated area of the site or community that is solely education based or are there groups of teachers that share how they use this site and contents in the classroom?  More specifically computer tech type classes. Hoping to hear back from some fellow educators. Regards, MyDemonsTech 

Topic by MyWlakeTech   |  last reply

Joining carpet pieces

I'm looking for ideas on how carpet pieces might be joined together into a whole (e.g. rugs made from carpet samples). The gaffer tape solution which is posted all over the web in tutorials isn't strong, only lasts a few months and doesn't work well with small carpet pieces.  I've successfully sewn carpet piece in the past with fishing line (so the stitches are strong and invisible) however this technique only works well with larger pieces due to the time it takes and amount of work.  Has anyone here tried any other techniques and been successful with both large and small carpet pieces?  My other idea was to use wood glue to glue the pieces to a hessian sheet.  I haven't tested this but the hessian base on most carpet pieces should merge well with the hessian sheet. thoughts or ideas appreciated.

Topic by garrettlynch   |  last reply

Air cannon

After wanting to make an air rifle for awhile I have finally decided to do it.  I plan to use 80-100 psi from a bike pump to power it.  I plan to use a 1/2 or 3/4 inch QEV (something like this;=1495573897&sr;=8-12&keywords;=3%2F4in+quick+exhaust+valve).  Do you guys know if a 2L soda bottle would be a good air tank or should I spend the money to make a pvc or galvanized steel one?  Would an air gun connected to the QEV work well?  Thank you for your time and help                        -James

Topic by TypeNameHere   |  last reply

Looking for someone to help buld an Arduino linear measurement project.

I'm looking for someone to help me build an Arduino linear measurement project. I need to measure less than 6" stroke with some accurate repeatability. I'm willing to pay for the programming and any parts I might need. Email me if you are interested in working on this with any questions you have... Thanks, 

Topic by rpmlou 

Reduced views

I am feeling a little foolish while writing this, but I have noticed that the views per instructables has reduced remarkably. Earlier the instructables featured on the homepage had around 5000-7000 views in a single day and now that number has reduced to 500-1000. for example- and i would like to add that these instructables are Fabulous. Not only this, the views on a normal featured instructables has also reduced. Is it because of that, that too many Instructables are being featured? I don't know, but I think something needs to be done to address this issue.. If you agree or disagree please leave your valuable suggestion.   Credits: Wooden USB-stick by X-plain,  Live Instructables Followers Counter by Nikus,  Sustainable Geometry by ENGL212.

Topic by Pranav Jhunjhunwala   |  last reply

Science of Baking class project doesn't work

When I go to the last step of the Science of Baking class to post my class project picture, I get one of two things: 1) The "Class project" / "I made it!" box is missing entirely, and the class questions are visible as normal or 2) The "Class project" box is visible, but contains only the text "Share a photo of your finished project with the class!" and a "Show more" button, which does nothing when I click it, and meanwhile the class questions are missing entirely.  I've tried refreshing the page, re-starting the computer (it re-started itself because that's how it rolls, and then I re-started it intentionally to see if it would help), and trying on two other computers, all with the same results.  The operating systems and browsers I've tried are Windows XP with Chrome, Windows XP with Firefox, and Windows 8 with Chrome. The class projects in the Knitting class are working fine, and the one for Science of Baking was working fine last time I saw it, which was Wednesday. EDIT: Added Screenshots from the first computer (XP w/ Chrome). Apparently sometimes the non-working "Class Project" box disappears and the questions appear when the page finishes loading (hence the loading indicator in the screenshot), but not always. EDIT2: Added link to class project page

Topic by christa627   |  last reply

Can a cracked guitar neck be fixed?

Hi, I finally signed to Instructables. :) My colleague is a big DIY guy and that's how I came across Instructables. Today, while searching for something I came across homemade recipes for musical instruments and that really hooked me on. Especially the one on turning an 6-string acoustic to bass acc. :) I had tried learning the guitar but didn't want to spend too much on the instrument, so I bought a second hand one from a garage sale (proceeds were for the city's stray dogs - so for me it was a bit of a win-win...almost :) ) What I realised much later is that: 1) The wood under two of the tuners (on the under/ventral side of the guitar) has splinters 2) One of these tuners has lost a fastening screw because the hole in the wood has widened and splintered a bit 3) the base of neck, just before the curve block that connects to the box, has a 1-2mm crack running across it (horizontally) Question is, can these issues be fixed so that a beginner like myself or someone who really doesnt have the money to own a guitar but wants to learn can still use it for some time? I never found the time to go to a music shop to have it checked. I also feel they will probably turn me away because they are more interested in selling guitars than fixing them. I really dont want to just throw it away. Second hand it may be, it just doesn't feel right... Your inputs would be greatly appreciated. Thanks! P.S.: Am at work right now but I will try and post images of the guitar as soon as I can. I had taken photographs of it a looong time ago. As a result, tuning goes off every now and again. On a colder day, tension increases and the crack widens. Update: Terribly sorry for the delay in uploading the pictures. I had a set that I had taken a year or so ago but I seem to have deleted them. Just got some time off work, here are the pictures. The crack, which I had earlier described as horizontal, is in fact, vertical. So much for my memory...

Topic by aristarkhos   |  last reply

Make something out of a beer bottle and win up to $1000

Lucky Buddha Beer is offering up to $1000 in craft store gift cards for the best re-use of its bottles. They’ve got less than 50 entries and there’s less than a week left. Check it out:

Topic by luckybuddha   |  last reply

Things to do with LCD backlight guide plate and polarisation films?

I received about 15 damaged laptop screens and took them apart to get the CCFLs and inverters which I'll combine into a modest spotlight for video recording. From each laptop I also gained some films and the light guide panel. I believe one of the films from each is just a simple diffuser whilst the other two appear to also be blurry polarisers. Finally, each screen has an acrylic light guide which refracts the light 90° and does so evenly by having some kind of bumps or dots spaced out according to the "diffusion equation" so there are more further away from the source of light (which comes from the side).  Any ideas for what I might use these films and plates? I do have a lamp project for which I can use the diffusion film but the polarising films would probably absorb too much of the light.

Topic by THX 1138   |  last reply

What choice of motor for a robot

Hello, I'm making researches about electric motors, I know very little about them and it seems to be a vast world. I don't have any detailled project yet, but I'd like to make a small robot that would be capable to move, that implies using electric motors. Forums have many useful data about them, but what it lacks is precise user reviews: what type of motor would you use the most, and why? Is it simpler to use servomotors over DC, or brushless? Prics must be a criteria of choice, but can I found cheap motors with good performance? Thank you very much for your help

Topic by armandbon   |  last reply

Inbox Improper Message

Hi when I click on my inbox in instructables it gives me my past message and says "Sent a few seconds ago" I'm not even sure if I receive messages anymore. I have a Mac and use firefox to view Instructables.

Topic by Kris82 

Refreshing for every Lesson

Ok, this happened to me on the lastest Google Chrome version on a WINDOWS 10. ..And an Amazon Kindle Fire's Silk browser! The following captures/page were: and

Topic by Bantman   |  last reply


I am currently taking my DT A-level and as part of our final project we have been instructed to find a client with a product in need to be manufacture and designed and to do this for them, with them in the end being able to keep the final designed product, however they would need to fund the project. So I am looking into finding a client with a unique project, that uses multiple materials and processes for me to design and make for them, that would be willing to give me regularly updates and feedback into their views on the project so the final product will be what they wanted. If you believe this to be you please contact me and we can discuss it further! 

Topic by SophieW24   |  last reply

New Channel for Educators - a call for projects

To the teachers, educators, instructors, advisers, Scout leaders, home-schoolers, unschoolers, and regular folks who just really want to help out a teacher.... I'd like to present to you the new, never-before-seen channel exclusively for educational content! That's right. We're trying to put everything all in one place to make the site easier to sift through as an educator. Need a project to accompany a unit on covalent bonds? What about an activity to teach kindergarteners to share? Hands-on projects are awesome teaching tools, and it's about time for those projects to live in one place. It's a mostly-empty channel at this point with only a handful of guides in it (and select few projects that I unilaterally recategorized because they were too perfect not to include), but it'd be nice to grow it into a large enough section of the site that it becomes actually useful to teachers. If you don't mind spending a little extra time on the site, I'd really appreciate it if you could recategorize some of your explicitly academic content into the new Education channel within the Living category. We're trying to load this new channel with materials that include the following: subject areas for the project, recommended age ranges, and the learning objective(s) for the project or guide. We'll be running a contest for teachers starting in December, giving away class sets of Instructables pro memberships along with the usual fare of Apple products and Amazon certificates. The MOST IMPORTANT elements of anything placed into this new channel are as follows: subject area age range learning objective If you want to recategorize any projects you've done that are specifically for teachers, you may. What would be most helpful is to create a guide of useful projects that is tied to a specific learning objective. Check out what the Children's Museum of Houston did for an example of what we're looking for in this channel. Checking for understanding: 1- What are the three most important ingredients for a project added to the Education channel? 2- What category is the Education channel in? Extra Credit- Do you have to be a teacher to enter a project or guide into the new channel? Extra Extra Credit- What are the three most important components of a project entered into the Education channel?

Topic by wilgubeast   |  last reply

Outdoor RGB LED Strip Failure

Hi all,  I've had quite a modest installation of RGB LED tape (45 meters ish, split into more manageable circuits) around the perimeter of my decking. This uses the commonly available 5050 RGB LED Strip light, the type with the epoxy covering the tape and also an outer sheath to protect it from water ingress.  I had heat shrinked the ends and also applied multiple layers of liquid electrical tape where a connection to a 4-core cable was needed. This has held up well for some time.  After about 2 years, I noticed that some of my RGB LED tape runs were sort of 'corrupting' where a small amount of moisture had got in, and shorted the RGB channels so that no matter what I feed into the tape, it always output white (or some other combinations or colours). Still, I ignored this, as it didn;t bother me too much.  These ran back to a central controller, which did the DMX control and amplification of the 12v single.  Anyway, to cut a long story short: Yesterday I smelt smoke.  I was walking around the garden and I noticed that one of the strips had caught fire, at a single point in the middle, and was burning a hole through my decking!  Again, long story cut short, I put this fire out and looked closer. The strip was so badly burnt that I can't determine what went wrong here.  I'm thinking maybe a resistor burnt out and caught fire? The tape has been running 'on' for quite some time (weeks) so this is a possibility.  Another possibility is that there could have been a short between 12v and ground, which caused heat. Now, there aren't any fuses on the 12v rail (fuse and circuit breaker protecting the 240v side) but I wouldn't have thought that this would protect me from a fire anyway!  I'm interested whether anyone else has had a similar experience or has any suggestions as to why this has happened.  I love these RGB LED strips, use them a lot in my house, but after seeing this, I'm not a little more dubious to keep using them.  I'm an electrical engineer (in the making, at University) and this has stumped me!  Thanks Joe

Topic by joearkay   |  last reply

Problem with ATtiny85 IR controlled LED

I am making a LED Light Stick with IR control to change the colour. Uploaded the schematics I made. Is there any mistake ? Do i misunderstand anything ? If yes, please forgive me, I am a complete noob and here to learn. I am going to add a 5v regulator to the Attiny85 power supply. And 380ohm resistor from pin5,6,7 to the corresponding transistor's base pins. I planned to use S8050 NPN transistor. How i calculate the things: 1. The RGB LED Strips i using is rated at 15W/metre @ 5V . Power supply i am using is 6V which is 4xAAA battery .I apply P=IV and get 2.5A/metre of current. Then I calculate current used in 60cm of LED Strips (2.5/100*60) and I get 1.5A current per 60cm. I devided the value by 3 and get 0.5A for each Red, Green and Blue pin. 2. Next step, I found the S8050 DC current gain (hFE/Beta) which is 40 and apply the formula Ic/Ib = B (Ic = 0.5A , Ib = unknown, B=40). I get the Ib of 0.0125A. Which mean i need 0.0125A of current in order to Fully-On the transistor at Ic=0.5A @ 6V. 3.To find the resistor value from Attiny85's Pin, I apply formula Ib = (Vb-Vbe)/Rb (Ib=0.0125, Vb=5 because the power supply of Attiny85 is 5v not 6v , Vbe=0.7V , Rb = Unknown) and i get value of Rb = 376ohm approximate to 380ohm. Another issue is that i didn't really know how to write the code. analogWrite seem didn't work for ATtiny85 sincce there's just 2 analog output for the controller. Or delayMicroseconds will work ? But i could'nt figure out how to write the code. I am very new to arduino. I know i should start at the basic first but i really need to get this project done. And please forgive my language. I didn't know English very well. Thanks a lot.

Topic by Sooncheng 

Project for vector calculus

Hello there, So, for my project in Vector Calculus: The suggestion is that we pick a certain "curve" within a country road. We are to log longitude, latitude and altitude while we drive this "curve" for approximately 15-20 seconds. With the data from the latitude-longitude-altitude "logger", we are to perform the various vector calculus principles we have learned in class. Instead of driving the road, I would like to attach whatever latitude-longitude-altitude logger to a boomerang, and get my curve through flight. Does anyone know which sensor I should be looking for? A bit about me: I am currently an electrical engineering technician in product development for a motor-controls company. I mostly test hardware/software, which is designed by our in-house engineers. I am very comfortable with soldering, visual inspection of PCBs, schematics, and general electrical engineering knowledge. Does anyone have a feasible idea for getting a gps unit onto a boomerang, and be ale to transmit the data to me in real-time? Thanks in advance.

Topic by PaulP292   |  last reply

Request: DIY LED Nightlight Outlet Cover

Hi all, I have been scouring the web and have yet to find what I am looking for.  I have seen a couple of different LED lights embedded in outlet covers and switchplates, but I need to do-it-myself because whoever cut the outlet holes in my house clearly had the shakes, and I want to convert the larger size custom covers I need to have LED lights especially for the kitchen and the bathrooms.  I also want to put them into covers that have unusual configurations, such as two outlets and a switch, etc. I have a few things I need.  (1) it cannot prevent full use of the outlet (I don't have any to spare)  (2) I need to be able to use amber lighting so as not to have the normal blue of standard white LED lighting wake me up, which should be easy enough.  (3) I would really love to be able to add them to GFCI outlets, too, but my understanding of how those work is limited. Any suggestions would be gratefully received.  I'm good with electronics right up until it involves building your own circuits, but my electrical skills pretty much top out at re-wiring a lamp, understanding how many amps it is safe to pull in a house circuit and how not to electrocute myself. I want to do this right, so it's stable long term and safe.  Again, thanks for any help, folks. -Lois

Topic by LoisBelle   |  last reply

What kind of power supply for this LED array?

Hi, My grow light failed on me recently. It's a series circuit of perhaps 3W diodes.  LED array pic: There are 18 diodes, and the colors are:  10 x 660nm (red), 3 x 630nm (red), 1 x 610nm (orange), 1 x 520nm (green), 1 x 430nm(blue), 2 x 450nm (blue), Total: 18 pieces Driver: I'm not really that knowledgeable about electronics, so what specs should I look for when buying a replacement driver? Is it as simple as getting something that is 8-12W like in the image, or is there more to it than that? Thanks.     

Topic by horsebones   |  last reply

Won't Stop going to Activity

It's letting me click "Explore" or "Contests" or anything at the top there, but when I'm on my profile, it won't let me go to discussions, settings or my drafts. Every time I click one of those, it loads for a couple seconds before going straight back to Activity. I'm trying to edit a draft I made last night. Please help!

Topic by Jada Durby 

Wooden blender base // power drill to food blender converter

I love projects which use power drills to power kitchen appliances: example 1 example 2 example 3 example 4 I live in a tiny home and the idea of having just one DC motor acting as a multi-functional appliances makes sense to me. Now, what I would love is to use my power drill as a food processor/blender. Actually, people have already made an immersion blender with a paint mixer and a normal blender by sticking the drill bit directly into an old blender blade. This is a great start, but it's not the best for when I need to blend something at high speeds for a long time. What would be great is to expand that last instructable with a base such that A) the vessel is upright and B) secure, and that C) I can safely push my drill against without worrying about twisting or anything. I've attached a potential schematic. Where I get lost is how to keep the rods/gears securely in place in a wooden/acrylic base without causing lots of friction against wood. I have close to zero handyman experience so if someone took this up I'd be eternally grateful! Alternatively, a belt could be used as done in food processors (example). It seems like it would be harder to drill downwards onto a kitchen counter, though.

Topic by rdecal   |  last reply

3D Printing Pen ABS plastic

Hi there, So I've seen a lot of stuff online about 3D printing releasing what are potentially toxic fumes, and I'm wondering how this transfers over to 3D pens?  We are looking to use them for workshops for kids, and there have been some concerns about it, so I'm just looking to see if anyone can point me in the direction of some info? All I can find is about 3D printing, and I can't imagine that using a 3D pen for half an hour on and off is the same as printing a whole object fume wise? Thanks!

Topic by sb9   |  last reply

Paint Plastic To Copper Tubing

I'm making a prop that requires a length of coiled copper tubing & I don't have the cash to buy it. I need a plastic tube that is malleable into a coil & I can spray paint it a copper color. I've experimented with some types of plastic cover electric cord & aquarium tubing & both, the plastic reacted with the paint & never dried.  I need to know what types of plastic tube I can ether paint myself & wont melt the plastic, or point me in the detection of were I can find copper colored plastic tubing, or name the types of plastic tube that wont react to certain types of paint.

Topic by elkaddalek   |  last reply

Attention all gamers! Attention all gamers!

My name is John currently I am looking to make full immersed video games the reason I am telling you this is because I need all of your help. If you have ideas about some video games that you want to see made contact me. If you have experience and want to help the dreams and ideas of others become realities contact me. Any and all who love video games and want to see your games be produced join me. Contact me either by email: or by comment on here  Your help and ideas are important to you which is why I ask you to join and help each other together our dreams and ideas will become real.

Topic by loudermilkj   |  last reply

Anyone interested in making a Video Game?

Hi. I'm looking for a group of people to help me make a Video Game. I have lots of ideas, but the big problem: I have absolutely NO coding, drawing, or music composing skills. I'm looking for people who have those skills, and would like to help out. I live in Canada, but you don't have to live there. I'm good with Skype, or something else. I'm fine with any software. I don't have any money, but I was going to put the games on Kickstarter, and I could pay people off that profit. I have ideas about most genres, like RPG, or action, or even a simulation. One idea is this war game where you command a small army, and attack other people. I can't really explain much, other than you can upgrade your troops, and unlock special troops, like Motherships. Or maybe a tycoon game. I don't really know, I mostly come up with ideas on the spot... So that's all I think i should say. If you need more questions answered about me, just ask. PLEASE HELP A GUY OUT!

Topic by NickelGames   |  last reply

How to power a brushless motor

How can i power a motor like this (with 3 pins) just to max speed? it's for a propeller clock. thanks

Topic by bfernandes1   |  last reply

500W electric scooter control and instrumentation with Arduino mega

1. Introduction DC 500W motor control with an Arduino mega to limit starting current and to vary the speed of the scooter. The battery is in 24V, 10A.h. The following table summarizes their characteristics: 2. Bibliography: Link download : sketch_escooter_feed_back_reel_V1.ino escooter_ampli_SIMULINK.mdl escooter feed back ISIS.DSN youtube  :  "study trotinette electric e-scooter 100W et 350W, wiring"  youtube;=75&list;=PLfZunVn_gcq7EOurXuWU2sRFmh6CbiUiL Article: «Study of electric scooters 100W and 500W (Arduino), Revue 3EI 2017» Pdf? Book «I realize my electric vehicle» at DUNOD 3. Open loop program To test the programming, we simulate the program in ISIS, as can be seen in the following figure. In addition, we have an LCD display to display data (duty cycle corresponding to the PWM at 32Khz, motor current, motor voltage, action on the pushbuttons, 4 push buttons are used. BP1 to manually increment the duty cycle, BP2 decrement it. BP3 set the duty cycle to 0, corresponding to the brake contact. The speed of the motor is practically proportional to the duty cycle We made our own current amplifier called a step-down chopper but it is possible to buy a shield There are many cards for Arduino to control DC motors especially of low powers and also of great powers as can be observed on the following links. But all these chopper shields measure the current internally but there is no current limitation. In order to have a current limitation, an analog current loop is required using specialized AOP or IC or a fast digital current loop. But what should be the value of the limitation current? The choice of the current value is normally for the 1-hour operation service in order to be able to carry out relatively long climbs without reaching the critical temperature of the engine. In our case, the limitation current must be Limiting motor = Power / Upper battery = 500W / 24V = 20A In addition, the power transistor of the chopper can only support 50A in our case. But in open loop, it has no current regulation, so as not to exceed the maximum current, a ramp of the duty cycle will be used. A 0.1 second interruption routine will be used to measure the voltage of the current (sample measurement, sample). This sampling time is arbitrary but does not allow to be faster than the rise time of the current because the electric time constant of the motor is L / R = 1.5 ms. Open loop operation with a 25.5s (8bit) ramp and 0.1s interrupt routine provides a good understanding of the operation of a DC motor drive. The display will only be done every 0.2s to have a stability of the digits on the screen. In addition, a digital filtering will be done on the current and the voltage on 4 values therefore on 0.4s. [b] Algo open loop [/b] Interrupt Routine All 0.1S Read voltage and current Loop loop (push button scan) If BP1 = 1 then increment PWM If BP2 = 1 then decrement PWM If BP3 = 1 then PWM = 0 Displaying variables every 0.2s Code: [Select] // include the library code: #include #include #include #define SERIAL_PORT_LOG_ENABLE 1 #define Led     13       // 13 for the yellow led on the map #define BP1     30       // 30 BP1 #define BP2     31       // 31 BP2           #define BP3     32       // 32 BP3 #define LEDV    33       // 33 led #define LEDJ    34       // 34 led #define LEDR    35       // 35 led #define relay   36       // 36 relay #define PWM10    10      //11   timer2    LiquidCrystal lcd(27, 28, 25, 24, 23, 22); // RS=12, Enable=11, D4=5, D5=4, D6= 3, D7=2, BPpoussoir=26 // Configuring variables unsigned   int UmoteurF = 0;  // variable to store the value coming from the sensor unsigned   int Umoteur = 0; unsigned   int Umoteur2 = 0; unsigned   int Umoteur3 = 0; unsigned   int Umoteur4 = 0; unsigned   int ImoteurF = 0;  unsigned   int Imoteur = 0; unsigned   int Imoteur2 = 0; unsigned   int Imoteur3 = 0; unsigned   int Imoteur4 = 0;            byte Rcy=0 ;    // 8bit duty cycle unsigned    int temps; // the setup function runs once when you press reset or power the board void setup() {   pinMode(Led, OUTPUT);   // Arduino card   pinMode(LEDV, OUTPUT);   pinMode(LEDR, OUTPUT);   pinMode(LEDJ, OUTPUT);   pinMode (PWM10,OUTPUT);     // Pin (10) output timer2   //  digitalWrite(LEDV,LOW);   Timer1.initialize(100000);         // initialize timer1, and set a 0,1 second period =>  100 000   Timer1.attachInterrupt(callback);  // attaches callback() as a timer overflow interrupt   lcd.begin(20, 4);    Serial1.begin(9600);   TCCR2B = (TCCR2B & 0b11111000) | 0x01;         //pin 10  32khz                                                   //   //   analogWriteResolution(bits) lcd.setCursor(0,1); lcd.print("Rcy"); lcd.setCursor(10,1); lcd.print("Um"); lcd.setCursor(5,1); lcd.print("Im"); lcd.setCursor(10,1); lcd.print("Um"); lcd.setCursor(20,1); // 4 lines display * 20 characters lcd.print("BP1+"); lcd.setCursor(25,1); lcd.print("BP2-"); lcd.setCursor(29,1); lcd.print("BP3=0"); } // Interruptions  tous les 0.1s void callback()  { temps++; //toogle state ledv for check   if ( digitalRead(LEDV)== 1 ) {digitalWrite(LEDV,LOW);}     else {digitalWrite(LEDV,HIGH);}     analogWrite(PWM10,Rcy);   // frequency Umoteur=analogRead(A0); Imoteur=analogRead(A1); Imoteur2=Imoteur; Imoteur3=Imoteur2; Imoteur4=Imoteur3; ImoteurF=(Imoteur4+Imoteur3+Imoteur2+Imoteur)/4 ; Umoteur2=Umoteur; Umoteur3=Umoteur2; Umoteur4=Umoteur3; UmoteurF=(Umoteur4+Umoteur3+Umoteur2+Umoteur)/4 ;   }// End routine // Loop corresponding to main function void loop() {    // BP + LED   if ((digitalRead(BP1))==1) {     lcd.setCursor(20,0);      // Column line     lcd.print("BP1");     digitalWrite(LEDR, LOW);        digitalWrite(LEDJ, LOW);     Rcy++;                        // PWM incrementation     if ( Rcy>254)  {Rcy=254;}     delay(100);               //8bits * 100ms = 25S increment 25ssecond slope     }        if ((digitalRead(BP2))==1) {     lcd.setCursor(20,0);     lcd.print("BP2");             Rcy--;      if ( Rcy<2)  {Rcy=2;}  // PWM almost at 0, engine stop         delay(100);      digitalWrite(LEDR, HIGH);     digitalWrite(LEDJ, HIGH);     }   if ((digitalRead(BP3))==1) {     lcd.setCursor(20,0);     lcd.print("BP3");      Rcy=2;               // PWM almost at 0, engine stop     } if (temps>=2)  { lcd.setCursor(0,0); lcd.print("                "); // Erase line lcd.setCursor(0,0);     lcd.print(Rcy); lcd.setCursor(5,0); ImoteurF=(ImoteurF)/20;     //resistance (5/1024)*(10/0.25ohm) si ACS712 66mV/A                            // For resistance 1ohm (ImoteurF) / 20; Simulation 5/25 lcd.print(ImoteurF); lcd.setCursor(10,0); UmoteurF=UmoteurF*10/38;                              //10/38   10/30 simula if (Umoteur>ImoteurF){UmoteurF=UmoteurF-ImoteurF;  }  //U-R*I lcd.print(UmoteurF); temps=0; }// End if time    } // End loop Since there is a limit of 9000 characters in the forum below Open loop program feature previous The interrupt routine lasts only 250 microseconds, the loop of the main program which scans the action of push buttons is 13micros and the display time of all data is 11ms. Thus, it is possible to improve the sampling period and thus the speed of the regulation of the current. The Arduino makes it possible to make the instrumentation of the scooter so to know the power, the consumption in Ah and Wh, to measure the speed, to know the consumption according to Wh / km, to measure the temperature of the engine, Have a safe operation. But for now we will see how to limit the current 4. Closed loop program, limited current control The sampling period will increase to 0.01 seconds (interrupt routine) If the current is less than the desired value, then the duty cycle can be increased or decreased to the desired value which is the setpoint. On the other hand, if the motor current is greater than the limiting value, there is a rapid decrease in the duty cycle. So as not to exceed the value of the duty cycle if it is saturated to 254 maximum and to the minimum value 6. Code: [Select] if (Imoteur<4000)                    // No current limitation at (20A * 10) * 20 = 4000   {if (consigne>Rcy)   {Rcy=Rcy+1;}   // Pwm ramp + 1 * 0.01second pure integrator    if (consigne    if ( Rcy>254)  {Rcy=254;}           // Limitation of duty cycle    analogWrite(PWM10,Rcy);   // Frequency 32kHz timer2}         } if (Imoteur>4000)  { Rcy=Rcy-5;              // No current filtering, to be faster                     if ( Rcy<6)  {Rcy=5;}       // Rcy is not signed, nor the PWM therefore Rcy minimum must not be less than 6                   analogWrite(PWM10,Rcy);   // Frequency 32kHz timer2}                        } 5. Closed Loop Program, Limited Current Control with Acceleration Handle An acceleration handle provides a 0.8V voltage when not operated and a 4.5V voltage when the handle is fully engaged. Instead of using pushbuttons to increase or decrease the speed setpoint, an acceleration handle will be used Code: [Select] Upoignee=analogRead(A3); // The relation in Upoign and the setpoint which corresponds to the duty cycle corresponds to if (Upoignee>100) { consigne=(Upoignee/2);     //0=a*200+b    et 255=a*800+b                      consigne= consigne-100;                   }                            else { consigne=0;   }               if (Upoignee<100) { consigne=0;  }     // redundancy     6. Temperature and safety program of the motor with the current measurement The outdoor temperature measurement can be easily performed by the LM35 component which charges 0.01V by degrees Celsius Code: [Select] temperature=analogRead(A2); //lm35 0.01V/°C temperature=temperature/2;       // Temperature coefficient lcd.setCursor(5,2); lcd.print("      "); lcd.setCursor(5,2); lcd.print(temperature);   // Display in ° C lcd.setCursor(9,2);      // Erasing secu display lcd.print("     ");   if (temperature>80 ) {lcd.setCursor(9,2);         // If motor external temperature is above 80 ° C                      lcd.print("secuT");                       Rcy=0;} In addition, thermal safety by measuring the motor current will be added. If the limitation current is greater than 10s then the motor will no longer be powered for 30s. A "secu" display will appear on the LCD display. This safety makes it possible to cut the motor on slope too high and when blocking the engine but it would be necessary to add the measurement of the speed in the latter case Code: [Select] if (timesecurite>=10000 ) {flagarret=1;      // If limitation current for a current of more than 10s                               timerepos=0;                               consigne=0;                               Rcy=0;                                 timesecurite=0;}       //   Then stop engine during a downtime    if (flagarret==1 ) {lcd.setCursor(9,2);         // If limiting current for a current of more than 20s                      lcd.print("secU");  }     //   Then stopping the motor for a stop time and display                                                     if (timerepos>=30000 &&  flagarret==1) {flagarret=0;                                           lcd.setCursor(9,2);      // After a rest time here of 30s                                            lcd.print("       ");   }   The display can be observed if the temperature is above 80 ° C Thermal safety by measuring the motor current (digital thermal relay) which allows to know the image of the internal temperature of the engine would be ideal. But for this, it is necessary to know well the thermal modeling of the motor. 7. Measurement of the energy capacity of the battery The energy capacity of a battery is in A.H, we will display the value in mA.H to have a high accuracy. The capacity will be in A.Second in the following equation. So to have in mA.H, it will be divided by capacity by3600. Capacity (A.s) n = I * Te + Cn-1 with Te = 0.01s and I multiplied by 10 So in the interrupt routine Code: [Select] capacity=ImoteurF+capacity ; And in the display Code: [Select] lcd.setCursor(0,3); // Display of energy capacity lcd.print("C mA.h="); capacity1=capacity/(18000);   //18000=3600*5  5=> Current measurement coefficient lcd.print(capacity1); To check a current of 10A with an adjustable resistor and after 30s, the capacity must be 83mA.H 8. Power and modeling with SIMULINK Modeling helps to understand the vehicle and its control. In addition, it is possible to compile the control part directly into the Arduino program from simulation under Simulink. But it will not be possible to simulate the instrumentation with the LCD display. In the following figure, we can observe the simulation of the programming of the chopper with the current limitation with Simulink. In the following figure, the green box shows the duty cycle control to vary the speed and the red border the current limitation. The controller of the control is here a simple integrator but it is possible to carry out a multitude of control. In the previous figure, it can be observed that the current is well limited to 25A from 2s to 9.5s. Then, the current reaches 10.8A under established speed regime at 22.5km / h. The dynamics are similar to the tests carried out. With a slope of 5%, the cyclic ratio reaches only 100% as can be seen in the following figure. The speed will reach painfully 19km / h with a current of 24A and a motor power of 580W. See article: Study of electric scooters 100W and 500W (Arduino), 9. First conclusion It is easy to control a 500W DC motor with an Arduino and some components So repair many scooters that are in DC motors. But it takes some knowledge (automatic, engine) to know how to properly manage the engine and limit its current so as not to damage it The display of the speed, the distance, the operating time to know the / km can also be realized with a menu 2. The .ino program as an attached file, But it is not possible to put an attached file in ISIS electronic labcenter? What is this forum? It would be desirable that the compiler could generate the.cof to debug in Isis and test the program line by line .... Arduino still has to make a lot of effort to be on the same level as other microcontrollers 10. speed measurement (tachometer) Velocity measurement is carried out using a hall effect sensor SS495 or A1324 which counts each revolution of the wheel. It is enough to enter the perimeter of the wheel of the scooter (130mm of radius therefore 0.816m in the case To have the speed, it is enough just to divide the number of turn of wheel on an arbitrary time of 1s to have a minimum speed of 0.81m / s therefore of 2.93 km / h. In addition, an average filter with 3 values will be used to display the speed. At 25km / h, there will be 8.5 laps. To count the turns, an external interrupt routine will be used on input INT0 21 of the mega card. To simulate the speed, a pulse on input 21 will be used with a duty cycle of 10%. Code: [Select] void INT0b21() {   Tspeed++;   // External interruption to count the number of turns } // In the set up declare the interrupt routine when the 5V edge of the magnet detection is done   attachInterrupt(digitalPinToInterrupt(21), INT0b21, RISING );  // External interruption // In loop if (temps09>=5)  {        // 1 second loop lcd.setCursor(13,2);      // Erasing speed lcd.print("kph     "); lcd.setCursor(16,2); speed1=Tspeed*2937;      //1tour*816*3.6/1s=2.937km/h speed2=speed1;           //Tspeed (rate/seconde) speed3=speed2; speedF=(speed1+speed2+speed3)/3000;   // To put in kph lcd.print(speedF,1);    // Display to the nearest tenth Tspeed=0;   // Reset counter temps09=0;  //reset time } To improve the accuracy of the velocity measurement, it is possible that the sampling time of the velocity measurement is dependent on the velocity. For example: For speeds less than 10km / h sample at 1second, but above 10km / h sample at 2 seconds. 11. Distance measurement for autonomy The distance corresponds to the total number of turns of the wheel multiplied by the perimeter of the wheel. So do not set the number of turns to 0 for each sample. On the other hand, the reset of the distance will be done when pressing the reset of the Arduino Mega. The distance display will be displayed to the nearest second. At 32km / h, it will take 2 minutes to do 1km as can be seen in the following figure: Code: [Select] void INT0b21() {   Tspeed++;   // External interruption to count speed   nbrRate++; } lcd.setCursor(13,4);      lcd.print("km      ");  // distance=(nbrRate*816)/1000;  //distance m distance=distance/1000;  //distance km lcd.setCursor(15,4);      lcd.print(distance,1);  You can observe the electrical installation with the chopper, the arduino, and the display when the program is set up 12. Synthesis The RAM space is used only at 4% and ROM space at 3%, for an Arduino mega. So we could take an arduino a little smaller. But, there are 8 Lipo cells to make the 24V power supply to power the engine via the chopper. Therefore, the voltage measurement of each element will be on the Arduino with a JST connector. This measurement makes it possible to know if a cell with an internal resistance which begins to pose a problem and to know if the balancing of each cell has indeed been carried out. It is possible to switch to 36V with 12 cells also with the arduino mega without using an external shield that multiplex 24 analog inputs on input A0 It is possible to send all data to a smartphone via Bluetooth HC06 via pins 20, 21, RX1 and TX1. But the application under android realized under JAVA Studio can not be shared on this forum. This part will not be explained. After having made the instrumentation of this scooter, a study should be carried out on the precision of the measurements, it is possible to read "Instrumentation of a low-power electrical motor vehicle" eco marathon "type Revue 3EI N ° 81, July 2015

Topic by Iutgeiisoissons 

how to make paper flowers easy

My youtube channel will help you make handmade products, DIY crafts such as crepe paper flowers, Quiet book, valentine card/gift, birthday card/gift, christmas card/gift, christmas card/gift,...  It is quite easy . There are a lot of kinds for you to make Flowers: peony, carnation, orchids,.... If you are interested in it please follow/like/comment my channel 1 how to make crepe paper flower - Sunflower   Easy and beautiful Paper Flowers - Gerbera paper tulip flowers to be continued...

Topic by duongjiangnan   |  last reply

"You're not allowed to look at that"

I recently did a big edit to an existing project*, and during the edit I set the instructable as "private" (I was spending a couple of evenings on it, and didn't want it seen in the mid-edit mess). Yesterday, I tried the same with another project**, but when I hit the button to make it private, I got a pop-up telling "You're not allowed to look at that". Any chance of a fix? * **

Topic by Kiteman   |  last reply

What are these?

Anyone recognize what these are and they're used for? The larger one has Bay19 SL2 on it. The smaller SL1. Both have a slit in the top.  I thought they might be some kind of glue dispensing cap or... Something along those lines. So, what exactly are they... Do you know? TIA, - chase -

Topic by -chase-   |  last reply

Thoughts for a fan for venting a homemade 3D printer enclosure?

Hello all, I'm in the early stages of building my own enclosure for my 3D printer. I'm going the route of building it using Ikea Lack tables. I'd very much like to put in a fan to vent the fumes from printing out the window via a hose. Originally, I was going to use a USB fan, but I'm starting to wonder if that will move enough air to make any difference. I was going to go with USB because I have no electrical work skills. I'm curious if any of you have thoughts, or have already come up with solutions for this. I'd be interested to hear any suggestions or advice anyone has. Thanks!

Topic by JesterPoet   |  last reply

Same email arrived too many times

I received 7 identical emails both to my email address and my inbox here on this site. As you can see from the times, they all arrived in a couple of hours. All of them encourage me to make something for the Lights contest, but one would be enough! :P This has already happened before with other "You might be interested in this contest" emails.

Topic by lindarose92   |  last reply

Use for rulers

I have five wooden 12 inch ruler. I used them in a project and don't need them any more. Does anyone have any ideas on what I can do? I don't want to throw them away. That would be a waste of $2.00. L: 12" W:1" H:~1/4"

Topic by ry25920   |  last reply

what CAD package/software do you use?

Hi - I have been using SketchUp for a couple of years, and grown reasonably proficient in its use.  However, it's not very intuitive in terms of being useful when trying to sketch ideas, find correct proportions, squeeze or stretch items until they "look right".  Having always to think in terms of creating drawings from extrusion of 2d surfaces is not often helping creativity! So, I am interested to learn and hear about anyone else's experience of using alternative CAD software in light of my comments about SketchUp - what do you use?

Topic by t.mikerust   |  last reply

Open page in new tab, not working

When I am writing or editing an instructables I usually put in some links, when entering the link I get a option to "Open page in new tab", The only issue is that when I enable and save that option the link opens in the same page and then the box is unticked when editing it again. I have included a short video about this Here SYSTEM: MacBook Air (Mid 2013) MacOS 10.12.3 (Beta 16D17a) 1.3GHz i5 2 cores with hypertreading 4GB 1600 MHz DDR3 Intel HD Graphics 5000 BROWSER: Safari 10.0.3 (12602.4.3)

Topic by DavidMontesin   |  last reply

Take a tour of Instructables!

There's so much cool stuff here, I thought people (new and old) might enjoy a guided tour. Instructables is a web-based documentation platform where passionate people share what they do and how they do it, and learn from and collaborate with others. These awesome people make it all happen. The seeds of Instructables germinated at the MIT Media Lab as the future founders of Squid Labs built places to share their projects and help others; more history is here. Instructables is the combination of a number of things. First, there are the Instructables themselves. These are step-by-step descriptions of things people want to share. They are educational, inspirational, and often replicable. The Dachshund Wheel chair is my favorite. A passionate user shared something close to his heart, and has had a positive impact on many lives.There's the whimsical: Magnetic Acrylic Rubik's Cube. And, of course, the whimsical inspired by the whimsical: Magnetic Rubik's Dice Cube. And, the plain ridiculous: How to Get a Free Yacht and its complete saga. A cornerstone of what makes Instructables great is the comments. People ask questions, give praise, or offer improvements; this sets up a conversation between the project author and the community. Check out this cookie recipe where the author responds to a question about substitutions for someone who wants cookies now.Many of the best Instructables have won one of our contests: Show Your Heart Valentine's Day Contest, Holiday Homemade Gifts contest, Take Thanksgiving to the Next Level contest, Halloween Project contest, and The Magnet Challenge. Instructables has a lively forum for opinion and discussion. Really smart and talented people hang out here. Have a look at a forum topic on water tunnel testing complete with Reynold's number equations.Finally, what really makes Instructables great is the community surrounding it. These are passionate people that want to share what they did and how they did it. In recognition of this, Instructables won the 2006 Wired Rave Award for industrial design. Instructables gave power to the individuals so they could positively impact the world. Also, check out some of the news articles about Instructables.

Topic by ewilhelm   |  last reply

The Bravery of Being Out of Range: A Technological Revolution

The 18th century gave us the beginning of the Industrial Revolution. Purpose-built factories for the new industries such as iron and textiles. New and improved methods of transportation, communication and production. It changed the way people lived / worked and it created / inspired a lot of what we still see and use today. This revolution had its negatives too. Jobs were lost to the industrial machines that did it better and faster, the poor and the working classes often had to endure grim living and working conditions. The black gold mined from underground, fuelled our thirst for advancement. Now in the 21st century, we are in the midst of the Technological Revolution. Ubers, drone deliveries, driverless cars and trucks, AI, Google, Facebook, Amazon Alexa, unmanned military vehicles, war by remote control and the bravery of being out of range. The drones, AI, robots and automation may not only take away our jobs, but potentially the need to leave the house or to have any real-world face to face interactions. They could re-define our lives, for better or for worse. Are you fearful? Wary? Or do you embrace the changes going on all around us?

Topic by ThirdEarthDesign   |  last reply

Labyrinth - What movie prop can I make?

Jim Henson's Labyrinth is one of my favourite movies of all time, but for the life of me I can't think what would be a good prop to re-create from the movie. Does anyone have any suggestions or inspiration for me?

Topic by ThirdEarthDesign   |  last reply

Wireless FM microphone real time voice/play transmitter

Hello I am looking to buy/build a small FM wireless transmitter with built in microphone (similar to karaoke but not exactly ) to transfer voice or sound  from playing  musical instrument  to earphone. It is meant only for practice purpose so does not need  high power, the distance between the microphone (the transmitter ) to earphone  is like from mouth to ear a few centimeters say about  50 cm. I am electronic junior engineer and have knowledge and experience in electronics mechanics and wave buy. Before trying to develop a new product  I was looking for a readymade shelf product. The first way I have searched the internet and reached manufacturer of Bluetooth solutions because of the plenty of Bluetooth earphone that are on the market, but quit a short time after I got some answers from the the Techs engineers  of the manufacturers that Bluetooth will not be my solution because It was not originally designed for true real time transmitting. The main problem is the latency time because there is a delay between the voice or play start until I hear it in the earphone there is improved in Bluetooth 4.1 and 4.2 that is 38 MS and may be not enough while fast playing, So as I was advised I started looking in the RF FM area. FM transmitters are long time in the market of stages and performers, there are high power grate quality transmitters that cost hundreds of dollars. Here is the summary of what I need :        I will need the smallest device (PCB) can be like FM spy bug transmitter. built in microphone (on the PCB ) , built in battery compartment (on the PCB ),built in antenna a copper loop on the PCB (no wire) Since there may be some problems like saturation of microphone or other problems with band width or  sound and sensitivity, sensitivity and control for the Microphone is important. Easy calibration of  tuning and stability , may be digital tuning is better. One option is to use the standard of radio FM 88-108 , but it possible that I can use FM VHF or UHF system that have both transmitter and receiver . If there are no ready made products thatn I can easy build a kit , or from schematic diagrams I will be thank full if you have any ideas. Nevat Ben Haim Recomp Computers

Topic by Nevat   |  last reply

Waterproofing micro USB B port on waterproof project box

Heyo, I am in need of a way to waterproof a micro usb B port (or water-resist since the port will only at most be rained on) of a microcontroller (the Adafruit HUZZAH)  in order to access the USB port (for charging and reprogramming) without having to open the case. I am open to any ideas that would keep the box watertight and not having a wire hang out of the box anywhere. I've searched for a bit on google and found nothing that will help me. If anyone has any idea or experience with this issue some advice would be greatly appreciated! Thanks!

Topic by bigjohn412   |  last reply