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your comment please on ARM development board

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So, you say the whole problem is that PC crashes frequently. The best cure would be to install a reliable Linux distibution such as Debian on this PC. They can run for years without reboots. This way you don't need a different box. What tasks is the PC doing? Perhaps you can simply use R-Pi or BB instead of PC.

You do not need port 22 for SSH, Any port will do. And yes, you can install/change software on Linux without rebooting without any problems.
 
KISS

Your post gave me lots of wisdom!

I thnk you very much.

I'm putting it all down in my notes to not miss anything and work out answers for each.

The linear-motion actuator of Fiegelli is just what I was looking for (**broken link removed**).
However it is highly expensive - 70$ a piece (I wouldn't need more than 10 pieces).

Are you familiar with something similar and less expensive? perhaps one that has lower force and speed.

Thanks a lot KISS for your post.

ElectroRF

The idea is not necessarily to turn the PC off, but to use the ON/OFF nature of the strip and the control of the strip ti be the interface.

e.g. You make something that when power is applied, the servo does it's thing.

So, check out Moxa or Lantronix: https://www.moxa.com/product/NE-4100T.htm These have a few TTL I/O ports.

So, let's say you have a program on the PC that resets a watchdog timer. The watchdog timer goes off an an email is sent to you. Alternatively, the linux box could use Ping. Then by connecting to the serial server, you could activate a TTL port.

The device you build, just has to look at a TTL

So ask yourself a few questions:

1. How much automation do I want?
e.g. email notification that server is down, automatic

2. How can I tell server is down?
a) Ping and is ping allowed?
b) Watchdog timer. Server talks to device every so often and when it fails, a reset happens.
Boot time + 50% could be the watchdow time.
c) The applications no worky

3) How many do I need? How cost effective using learning curve issues etc.

4) Can I use commercial hardware?

5) Yes, you did mention an RC servo, but you have to convert rotary to linear motion. Why not go linear from the start"
Options:
a) Linear: **broken link removed**
b) Floppy drive linear actuator fitted possibly with a spring.

6) Who is going to use it? How user friendly does it have to be? Is it more like person A discovers server down and makes a phone call to your IT department where 1 or 2 people are allowed to operate the device.

7) How secure does the activation have to be? That's where ssh comes in to play. You can set ssh up so that passwords are not required on machines that use it. Certificates are used instead. They may have to be Linux boxes or Windows boxes using Cygwin.

I once set Cygwin up for a man-in-the middle where an external access via VPN (allowed access to a machine that had access to a secure server), but I wanted to access the secure server via VPN directly. Specifically, I wanted to be able to transfer files from the secure server to my laptap logged in from home via VPN without transferring it to an intermediate machine first. It worked for while until they fixed it.

They are ideas and ideas that may not work, but 99% of the connectivity stuff may be done for you.
It's possible that the only glue might be a small PICAXE program that responds to a TTL port.
 
Hi NorthGuy

The PC is running many application and many external HWs, therefore it gets stuck from time to time.
It must run on Windows..

Thank you for the indication that I could burn SW remotely without needing to reboot the BBB (BeagleBoneBlack).

So, you say the whole problem is that PC crashes frequently. The best cure would be to install a reliable Linux distibution such as Debian on this PC. They can run for years without reboots. This way you don't need a different box. What tasks is the PC doing? Perhaps you can simply use R-Pi or BB instead of PC.

You do not need port 22 for SSH, Any port will do. And yes, you can install/change software on Linux without rebooting without any problems.
 
I always like to just "brainstorm" or "think out load" so to speak and throw out some of the possibilities even if absurd.

So, just doing an ebay search, I found this: **broken link removed** and this: **broken link removed**

These https://www.hurst-motors.com/lalbsynchronous.html#buy look too fast and too expensive, but could work if limit switches are used.

Even rotary solenoids would have enough torque to work, but you CANNOT leave them on continuously.
 
The PC is running many application and many external HWs, therefore it gets stuck from time to time.
It must run on Windows.

Generally, Linux is much more reliable than Windows. You can count on it to run for years without a crash. If you applications crash, you can configure it to re-spawn the applications automatically. If your hardware-controlling applications are written in C, aside of GUI part, you can re-compile them for Linux with little or no modifications. In other cases, you can find better open-source Linux applications that will perform the corresponding tasks better than their Windows counterparts. You also can easily control them remotely over the Internet.

To increase reliability, you should try to decrease the amount of components on your system, not to increase it.
 
Just to add some other questions/comments:

1. Servers are sometimes clustered rather than distributed. You mentioned at least 10 units and you have to count spares.

2. Mounting a "servo-controlled push button" may be an interesting feat in itself especially if you want no holes drilled. I'm envisioning a large strap with Velcro or something attached to a rack handle or some clampy gizmo. Minimize weight, If someone can order the parts and make the clamps overseas all the better for you.

As for an idea for a clampy thing, try two to 4 "Side Beam Connectors" I'm holding one in my hand right now for 3/8 all thread. **broken link removed** It gives you two 1/4" holes for a flat head screw about 3/4" apart and a tapped 3/8" at a right angle. Let's say I'm looking at a typical desktop and not a rack mount server.

I could lay two say 6" long pieces of angle on each side with four rubber feet on each, two on each inside near the corner. The feet would provide clamping and clearance for an underside 1/4" nut and some protruding threads. For now, I'm using four total beam clamps, but you might be able to use just one. Drill out two of the clamps for a 3/8" clearance hole. Now put two 3/8 all threads between to clamp the system. So you have feet pressing on the top of the computer and the side of the computer being pulled together with two 3/8 pieces of all thread. One side uses a tapped hole and the other would use nuts.

Lets say in the simplest case, use large fiberglass angle like say 2" or so and lets say the power button is 2" from the edge. You may be able to use another beam clamp off the side to drop the holder of the "servo button". The 3/8 hole would give you adjust ability and use another nut for a lock.

This may be overkill, but it just gives a place to start. You might end up gluing something to the side. Counter sunk rivets are cool and I could even send you a some from my large box. I'd have to check the size, but I think they are 1/8 diameter.

Big magnets are also possible and so is a couple of holes in the case.

If your servers are rack mounted then that's an issue.

3) If they are clustered, then the controller may need more ports, but you may only need one that say could connect to eight buttons,

4. Metric vs English?

5. Watch power crap and CE approval or at least make sure there are no EMI issues. I hate power bricks and wall warts, but they really make the design easier.

6. Remember that it should be easy to revert to the original form if the tools are handy. So, the nuts could be replaced by wingnuts and possibly thumbscrews in certain locations.

7. And last but not least is that you will likely have to mimic the pressing of a button with another button of your own. It may have to do the same sort of push, hold and release from an external button.

8. Not sure if say MODBUS or even RS485 could be in your future as well. You may not get the luxury of one IP address or even multiple open ports. So, the IT department might forward one port to your device and if you have a few servers located say in a few rooms, you may have to use some other cableing/protocal to get there. They may not have a public IP address that they could dedicate to your gizmo.

9. Does VPN enter into this at all and does it matter?

10. You also need travel and force. Asa dumb example, the guy at the other side of the pond could take a sheet of paper and make a tube the side of the button and close and tape the bottom of the tube. Let's say this is 1 cm diameter, They could then fill it with a common item like say sugar until the switch activates. So, you could compute the force needed neglecting the mass of the paper and tape, although not sure if the technique would work, Some buttons might take 100 grams force to operate.

11. Way out of line is to make the actuator tip a force sensor and it would not be unreasonable to make it a spring. It would be a LOT easier, if you could do it internally with a switch. The switch may not have to be the "power switch".

I know once I needed to know the approximate force needed to pull a drape so I used canned vegetables as weights. fishing weights might work.

Just don't take what I said here as workable. It is nothing more than a "place to start". Sugar may not be heavy enough.
I can measure up to 200 g. If it were two people in the US, one could say, it took 20 quarters and 10 dimes to activate the switch. (gravity - I forgot that you would have to turn the computer so the button faces up to test, but it would not have to be on.

So, I just briefly addressed shipping large items, metric vs English, whether or not the mechanical stuff for mounting can be made and/or purchased by the other office. You could send one as a proto.

What it does mean is that someone should send you a picture with a ruler in it of the typical server boxes and mounting means. The ruler allows you to make measurements.

80/20 **broken link removed** is neat stuff, but it's expensive.

Right now, I have no idea what specific problem has to be solved, but just anticipated issues not knowing much at all.
except: computer, overseas and 10 or so. Shipping big or heavy things is expensive. So, if the mechanical stuff can be bought and made in-house overseas, then all the better. So, someone might need a drill, sander, vise, drill bit, etc and a source of parts.

3D printing of plastic parts if you have to do that could add yet another wrinkle. See: https://www.shapeways.com/create

And when all else fails, read the directions: https://www.mupuf.org/blog/2013/05/...-suite-to-power-up-slash-down-your-computers/
 
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Note that the code is basically written for you: **broken link removed** Look at the repository.

It would take a while for me to begin to understand it.

Also note that Fritzing is used for the project. I know of it's existence, but never used it.

Note that in his implementation, it appears that no real irreversible mods are made except the possible the "cut the green wire". Not sure.

So, installing is potentially easy. He did have a slot available making the install even easier and it gives you a way to get wires to the outside.

The electro-mechanical activation is a major complication. To further complicate things, use a force sensor. :D

So, it looks like a lot of work
 
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