EQMOD Arrgghhh

[Rocket Pooch]

I do, but I can't be bothered to go over this again, and again, and again.

[The Thing]

Logitech or any compatible one, I use a logitech rumble pad you can get a wired or un-wired version.

http://www.logitech.com/en-gb/support/264?osid=14&bit=64

This may be an option

https://www.google.co.uk/shopping/product/14104444909035731853?q=Gamepad&client=firefox-a&hs=twX&rls=org.mozilla:en-GB:official&bav=on.2,or.r_cp.r_qf.&bvm=bv.51773540,d.ZGU,pv.xjs.s.en_US.jkEW54nYU50.O&biw=1366&bih=598&tch=1&ech=1&psi=V40pUvmjEoLW7QaUsYGoAw.1378454874315.3&sa=X&ei=XY0pUuPJHIeB7Qb1k4GQAw&ved=0CIMBEPMCMAE

You can use compatible ones they are cheaper.

Forgot to add I got the rumblepad because some wag got the pad to rumble in EQ Mod I like it.

If you join the EQMOD Yahoo group you can access a database of gamepads known to work...

[MarkS]

I do, but I can't be bothered to go over this again, and again, and again.

I didn't realise this had been covered before - I'll do a search through your previous posts.

[Ivor]

One thought is your hub sufficently powered? When you're moving the mount maybe it's pulling too much power and causing the connections to drop below 500ma.

[mickw]

Check power connection to the hub, my one had a habit of getting loose and disconnecting.

[Mike]

I'd say not enough amps going to your hub. Try a beefier PSU.

[MarkS]

I already tried to rule out power problems to the hub. It is mains powered and does not have a dodgy power connector.  It is sitting on the table so it doesn't move when the mount slews. Moreover, I've plugged EQDIR straight into the laptop so it doesn't draw power from the hub.  So if EQDIR is affecting the hub, I can't see how.

In the final tests I didn't even have the devices on the hub actually being used.  But they still disconnected and re-connected during a slew.

So the problem is now very easily reproducible and I'm gradually narrowing things down.

[Mike]

Then it is the power going to the mount that is at fault. Test the voltage pre-slew and during maximum speed slew. Make sure it doesn't drop significantly. If it does drop or oscillates then you have a PSU that isn't regulated well enough. You need a good stabilised power supply with high ampage (at least 6amps). The voltage needs to be constant or you will get comm failures.

Also make sure you're not trying to user it over too long a USB cable.

[MarkS]

I'm sure the mount power is fine - I was running the mount off a freshly charged car battery and the red LED light on the mount was constant - it didn't flicker or flash during the slew.  I will double check the voltage, though.

With the EQDIR plugged directly into the laptop port I'm not getting comms failures to the mount.  But I'm still getting the comms failures on the devices on the powered hub (which is also plugged into the laptop).  All my USB leads are sensible length - no USB extenders.

They're all very good suggestions though!

[Ivor]

So the hub doesn't have an external power source it relies on the power from the Laptop USB port? I believe the maximum you can pull from the PC port is 1A which would only power 2 devices on the hub.

Will your HUB support an external power supply?

Amendment -

I've just reread your post, you say

the comms failures on the devices on the powered hub

but can the transformer provide enough current, you want at least 2A.

[Mike]

Yeah always make sure you power the hub.

[MarkS]

Hub is mains powered.  It is 2A which is plenty adequate for the 3 devices I have attached.

I'll do some further experiments ...

[The Thing]

Check power connection to the hub, my one had a habit of getting loose and disconnecting.

One of my hubs lost its central power pin. Took me a while to spot!

[MarkS]

I spent some time last last doing some exhaustive testing and I'm now 80-90% sure of the cause.

The mount warning LED was indeed flickering during fast slews i.e. the car battery voltage was dropping.  However this was not sufficent to cause a communications failure to the mount itself. The only other device (except dew heaters) connected to the car battery was the Canon power adapter.  Tests showed that the devices attached to the USB hub would only freeze when the Canon was connected to the same hub and was also powered from the car battery.

So I think a voltage drop to the Canon (caused by the slew) caused a Canon USB communication failure which somehow caused communication failures to the other devices on that hub.  Is that likely?  It seems to be what I'm seeing.

Note that the USB hub itself is not powered from the car battery but from the mains.

[The Thing]

About time you sorted a mains powered supply for your observatory then... I've had no trouble when using a PC power supply.