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Servo Troubleshooting notes

Ed Nutter October 4, 2018

Servo Troubleshooting

Ostendorff

Forcing a servo to rotate when off can damage it.

Malfunction:Servo makes a grinding noise or acts erratic

Probable Cause

Corrective Action

Source

Examine gears for broken teeth

Replace gears

General

Malfunction:Servo Jitters

Probable Cause

Corrective Action

Source

Dirty potentiometer

...

Making a connection 1

Ed Nutter July 3, 20182 comments

In order for your system to control devices, you must be able to connect it to those devices.

Besides different sizes based on wire size, there are a few different styles of connectors that can be used.  There are also weather-resistant terminals that can be used if needed.

Ring

(Parks, 16)

- used for circuits that you don’t want to become easily disconnected

- ground wire attached to a stud

Push-On

- can be used on relay terminals

(Parks, 18)

- could be...


Troubleshooting notes from days past, TTL, Linear

Ed Nutter June 19, 20181 comment

General Troubleshooting

  • Follow safety precautions.
  • Always think “what if”.
    • Analytical procedures
    • Precautions when probing equipment
    • Insulate all but last 1/8” of probe tip
  • Learn from mistakes
  • Don’t start with electronic test equipment, start with analytical thinking.
  • If you get stuck, sleep on it.
  • Many problems have simple solutions.
  • Whenever possible, try to substitute a working unit.
  • Don’t blindly trust test instruments.
  • Coincidences do happen, but are relatively...

Circuit Board Standoffs

Ed Nutter February 2, 20183 comments

If you are unable to find a circuit board mount in the size you need, there is an alternative.  You could make them from tubing, like steel brake line, with a bolt in the middle.  You could use plastic tubing with a bolt.Using a solid rod is also an option.

If you opt to use some type of rod, there are some things to keep in mind.  Drill rod is very tough, but could be hard to thread smaller bolts.  Mild steel rod isn’t quite as tough, but it easier to thread. ...


Obsolete? Yes. Still in use? Yes. How do you use it? Ummm...

Ed Nutter November 14, 20175 comments

In today's world of constantly changing technology, quick parts availability, and seemingly endless options, some things can't change.  It isn't a big deal to wait a day or less for a computer upgrade to arrive.  It seems program size increases proportionally to hard drive size.  The old is discarded and replaced with the new.  Hard drives can hold terrabytes and even SD cards can hold gigabytes of information.

Now, suppose a system can't be changed.  It is still...


Intel 8088 - A blast from the past

Ed Nutter March 28, 2017

The Intel 8088 is an 8 bit processor related to the 16 bit 8086.

The Microcomputer class consisted of wire-wrapping the chips to perfboard using sockets.I had taken computers apart, soldered, etc., but had never used wire-wrapping to construct a computer board to that point.Most people carried the board to class.  A few people stared when I opened the plywood box with breadboard area, and plugged the full-sized power supply in.  The lid is wide enough to hold the 11x17 paper the...


My little runaway...

Ed Nutter January 18, 2017

Since most vehicles won't float and land gently from more than a few inches, some type of stand is needed to keep the vehicle stationary as work is being done.  It can also prevent crashes and broken things, which becomes more important as the vehicle becomes larger and heavier.

For now, most of my work is done with 1/10 scale or smaller vehicles, so I made a stand from leftover wood.  Full-size vehicles may require a hydraulic lift and jack stands.

Smaller vehicles can be held by...


It ain't heavy, it's my robot...

Ed Nutter January 3, 2017

Unmanned Ground Vehicles - Design considerations for man-portable/packable vehicles

A UGV is “a ground based mechanical device that can sense and interact with its environment.” (Carlson, How)

A Field Robot is expected to work outdoors, though generally not in rain or snow, including rough terrain, dirt and dust. (Carlson, Reliability)

A Man-portable robot weighs less than 40 pounds, or is capable of being broken down into subassemblies for two soldiers weighing less than 40...


Unmanned Ground Vehicles - Design Considerations for Snow and Cold Environments

Ed Nutter December 27, 2016

It's that time of year when the white stuff falls from the sky across the US, and with it comes lower temperatures. These conditions must be taken into consideration when designing a vehicle for outdoor use.

A few definitions from wikipedia:

Flurry: light, brief snowfall

Snow shower: intermittent snowfall

Light snow: over 1km visibility

Moderate snow: 0.5 to 1km visibility

Heavy snow: less than 0.5km visibility

Blizzard: lasts 3 hours or longer, sustained wind to 35mph, visibility...


Choosing a Microcontroller for Your Vehicle

Ed Nutter June 7, 20161 comment

There are many things to take into consideration when choosing a microcontroller or microprocessor for your autonomous vehicle.

Voltage

Some processors run on 5V and others use 3.3V.  Be sure to check the documentation before you buy.  Make sure your supply has a high enough amp rating that your microcontroller doesn't lose pwer.

Power

Can the system run using batteries?  Large, automotive sized vehicles can be run from large batteries or inverters in the vehicle.  Smaller...


Basic hand tools for electronics assembly

Ed Nutter November 20, 20153 comments

Though the software tools vary with different microcontrollers, many hardware tools are the same.


Choosing a Microcontroller for Your Vehicle

Ed Nutter June 7, 20161 comment

There are many things to take into consideration when choosing a microcontroller or microprocessor for your autonomous vehicle.

Voltage

Some processors run on 5V and others use 3.3V.  Be sure to check the documentation before you buy.  Make sure your supply has a high enough amp rating that your microcontroller doesn't lose pwer.

Power

Can the system run using batteries?  Large, automotive sized vehicles can be run from large batteries or inverters in the vehicle.  Smaller...


Troubleshooting notes from days past, TTL, Linear

Ed Nutter June 19, 20181 comment

General Troubleshooting

  • Follow safety precautions.
  • Always think “what if”.
    • Analytical procedures
    • Precautions when probing equipment
    • Insulate all but last 1/8” of probe tip
  • Learn from mistakes
  • Don’t start with electronic test equipment, start with analytical thinking.
  • If you get stuck, sleep on it.
  • Many problems have simple solutions.
  • Whenever possible, try to substitute a working unit.
  • Don’t blindly trust test instruments.
  • Coincidences do happen, but are relatively...

Basic Sensors for an Autonomous Vehicle

Ed Nutter March 27, 2016

The following are a few basic sensors that can be used to help an autonomous vehicle navigate its environment.

The faster the vehicle is traveling, the faster the sensor must be processed.  

Moving vehicles could knock something over or cause damage to a person or object if it collides with them.

Drop-off and line sensors function better when mounted to the front of the vehicle.

Drop-off and collision sensors should be mounted front and rear, if your vehicle can back up.


Intel 8088 - A blast from the past

Ed Nutter March 28, 2017

The Intel 8088 is an 8 bit processor related to the 16 bit 8086.

The Microcomputer class consisted of wire-wrapping the chips to perfboard using sockets.I had taken computers apart, soldered, etc., but had never used wire-wrapping to construct a computer board to that point.Most people carried the board to class.  A few people stared when I opened the plywood box with breadboard area, and plugged the full-sized power supply in.  The lid is wide enough to hold the 11x17 paper the...


Circuit Board Standoffs

Ed Nutter February 2, 20183 comments

If you are unable to find a circuit board mount in the size you need, there is an alternative.  You could make them from tubing, like steel brake line, with a bolt in the middle.  You could use plastic tubing with a bolt.Using a solid rod is also an option.

If you opt to use some type of rod, there are some things to keep in mind.  Drill rod is very tough, but could be hard to thread smaller bolts.  Mild steel rod isn’t quite as tough, but it easier to thread. ...


Making a connection 1

Ed Nutter July 3, 20182 comments

In order for your system to control devices, you must be able to connect it to those devices.

Besides different sizes based on wire size, there are a few different styles of connectors that can be used.  There are also weather-resistant terminals that can be used if needed.

Ring

(Parks, 16)

- used for circuits that you don’t want to become easily disconnected

- ground wire attached to a stud

Push-On

- can be used on relay terminals

(Parks, 18)

- could be...


Steering an autonomous vehicle - two basic ways

Ed Nutter January 15, 2016

While there are many types of steering mechanisms, for now, I will be concentrating on two of them.

The first is known as Ackerman-type steering. On a rear-wheel-drive four-wheeled car, the rear wheels push the vehicle while the two front wheels pivot left and right, either by using a servo or a geared motor, to steer the vehicle.  Understeer is when the vehicle tries to push through the turn too wide, possibly causing the vehicle to drive off the outside of the course.   ...


Obsolete? Yes. Still in use? Yes. How do you use it? Ummm...

Ed Nutter November 14, 20175 comments

In today's world of constantly changing technology, quick parts availability, and seemingly endless options, some things can't change.  It isn't a big deal to wait a day or less for a computer upgrade to arrive.  It seems program size increases proportionally to hard drive size.  The old is discarded and replaced with the new.  Hard drives can hold terrabytes and even SD cards can hold gigabytes of information.

Now, suppose a system can't be changed.  It is still...


Mounting plate for Arduino

Ed Nutter November 30, 2015

While having a breadboard with your microcontroller is necessary, it is very cumbersome if the two aren't fastened together somehow. You can buy mounting plates, but I choose to make one.