I have a lengthy project going on in the projects portion of this forum. I have been given a ton of help from forum members and learned a lot. However, I am running in to some issues as I add features to the project. I have a feeling, I am experiencing or will experience electrical interference/ noise that I would like help eliminating/preventing.
I know much detail is needed in order for anyone to advise on what I should do, but I am unsure what all details are needed. Just ask, I'll provide.
This project has an electric winch with cable (max amp believed to be 60amps). This lifts a head up and down.
A scooter motor like would go in a motorized wheel chair. This turns a roller chain and moves a head up and down a track.
Both these motors are controlled with motor drivers that are similar to this:
I have a wheeled encoder that reads the travel of the up and down movement to stop it in the correct place like this:
There is also a gear tooth sensor to read the gear teeth as the head travels.
There is a Servo Motor that controls the throttle of a gasoline motor like this:
All of this works basically.... However, especially the servo, seems to be experiencing some issues with moving when it shouldn't. Where should I start with adding hardware to help prevent noise/interference.
Here is a basic diagram of how it is wired. Not pictured are the encoder and gear tooth sensor. They are both getting their 5v voltage from the arduino's built in regulator and grounded to the arduino. Their signal wires are running to differing pins of the arduino.
Yes, the diagram is wrong. I do not have a picture of the actual wiring as of now. It is inside an enclosure. Many of the wires run through a drag chain which I know is an issue too.
I have redrawn the schematic, I think it is more correct now. I also included the wheeled encoder and gear tooth sensor. Both of these have resistors to pull the signal wires up to 5v.
The drag Chain that I am talking about runs from the enclosure where the mega and two motor drivers are to the "head" about 30' of wire runs through this path.
Included in the drag chain are:
Wires running from motor driver output to both the winch motor and scooter motor.
The signal wires and 5v/gnd from the arduino to the encoder and gear tooth sensor
The signal wire going to the servo motor and the twisted pair that goes to ground.
The 5v -12v converter wiring does not go through the drag chain. It connects directly to the battery with about 2 feet of wire. and the output side (5v) is about 18" to the servo motor power supply.
I have read that adding a capacitor between the 5v+ and Gnd of the servo would help with some interference? Would this help? If so, what size capacitor?
Are there other places I can add simple capacitors/resistors etc to help protect from noise interference?
Convert Unstable 12/24V DC Power Supply to Stable 5V DC Power Output
High Conversion Efficiency: Over 90%
Widely used in Automotive, Electricity,Surveillance Systems,Railway Signals, Instruments and Meters, LED Displays (LED Strip, Copper Led Strings), Cable TV, etc.
Package Contents:
1x DC 12V 24V to 5V 10A Converter Step Down Regulator
A lot of noise problems are caused by bad layout of wiring. Current has to flow from some source (battery, whatever) to the load and back. The path there and the path back should be together so there is no loop. If that's not the case then that needs fixing. Also, signal wires need to be separate from those carrying lots of current, while still obeying the rule of no loops. Photos will show this.
Without wishing to be rude if your wiring is as neat as your schematic (ahem) then you will have problems.
Wires running from motor driver output to both the winch motor and scooter motor.
The signal wires and 5v/gnd from the arduino to the encoder and gear tooth sensor
The signal wire going to the servo motor and the twisted pair that goes to ground.
Then it matters how they are organised and what kind of cable you used. At the very least the signal wires should be in separate cable and preferable screened, with the screen connected to 0V at the controller end only. Twisted pair helps too.
How many ground / 0V wires are in the cable? There should be at least 2, one for power and one for signals, and they should only meet at the control end of the cable.
Point taken. I am a big boy I can handle criticism. And to be honest, it is organized about as well as that schematic. This project has continuously grown from the beginning, and I have patched together much of it with parts/wire I had laying around. A complete rewire may be in order, but I still will need to know what my best approach would need to be if a rewire is necessary.
The wheeled encoder signal wires, ground, and 5v+ wires are all in one bundle. It is shielded wire.
The 5v ground and signal wire for the wheeled encoder is in one bundle of wire that is not shielded.
The servo motors signal wire is in a cat6 e bundle of wires. I am using one of the 6 twisted pairs for the signal/ground.
All of this above has to run inside the same drag chain (30’ parallel) the 4 output wires of the two separate motor drivers in the diagram.
I have 5 remaining twisted pairs within the cat 6 cable. Would it be better to use more of these twisted pairs instead of having them in a different bundle of wires that is unshielded?
I don't know how to tell you other than what I have said, maybe someone else will. Try searching for 'cable dressing'. A rewire is necessary based on your description.
Not possible. A cat 6 cable has 4 twisted pairs, so you cannot possibly have 5 remaining.
I am trying to respond too quickly. I have used one of the pairs. The rest are available. Sorry.
Most of these 1025 posts have been walking me through coding for this project. Yes, hardware has been discussed to some degree in it along the way.
I was hoping coming to this section to get specific help. I was hoping (because I don’t know electronics) that maybe there was simple things I could add to reduce noise/interference. Add filters, capacitors, resistors, etc.
The project does work as it is, but there appear to be some intermittent issues that I hoped I could work out without a complete and total rewire, maybe not…
"Wiring dress" - keeping supply and return wires. or control and ground wires bundled together and those two categories clearly separate from each other is absolutely crucial to reliable operation. It is in no way optional.
Well, the answer lies in your wiring. So it's futile to advise without seeing it. It's very rare that sub optimal wiring can be improved or fixed with only the addition of more components. That makes it the starting point of any productive investigation.
Ok, I can get some pictures, but be forewarned, it is messy. I don’t have a choice (or at least not that I know of) other than to include the “mains” that run from the output of the motor driver to the motors in the same drag chain with the signal wires for the encoder, gear sensor, and servo.
So, if they must run in the drag chain together, what is the best way? Could I run each of the signal wires in its own cat 6 “bundle”?
I think you are concerned we will judge 'messy' from an aesthetic point of view. While it is always aesthetically pleasing to see neat wiring that is not the main point, untidy wiring is likely to suffer noise problems, so will be at the heart of your problem. While I am looking forward to seeing your pictures, the fact that you say it is messy is a big pointer to what the cause of your problems is.
You haven't seen my work.... It is quite embarrassing to say the least. I will try and get some pictures uploaded because I want to learn, and I am sure I will have to rewire this project. However, at the present time, it does appear to be working correctly. Within the 1K + posts in my other thread pasted above, the thought is that it could possibly be code related, but not sure how. So, I am kind of a "if it aint broke don't fix it" kinda guy. I am sure it will brake and I will want/need to know what to do to fix it though. I am going to do some more testing, but I will post pictures....
Ok, I took a video of how the wires run. It’s awful I know, and I know y’all are going to tell me that a rewire is necessary, but I am going to say it does work. I have now ran about 6 hours with everything functioning as it should. So, it may look awful, but it is functioning correctly as of now.
Inside the control boxes is where the motor drivers are. One is in the metal enclosure. The other is in the plastic enclosure. The arduino mega is inside the plastic box with one of the motor drivers.
I am quite embarrassed to post it, but here it is:
