Allow laptop to enter sleep mode.

[PeterAB]

Hi,

SharpCap version 4.1.12637.0 (64 bit). Zwo drivers 3.24.0.0.

I have a puzzle that I am trying to work out. I would like to be able to have SharpCap running and connected to a ZWO camera and place my laptop in sleep mode. I would like SharpCap to recover from sleep mode and start operating exactly as it was then it went to sleep.

My trouble is that that with ZWO cameras, my computers will not enter sleep mode. The computers get stuck in a half way to sleep mode. This requires a hard reset of the computer with a time consuming reboot. Windows need to do some sort of recovery processing. The reboot is longer that a normal cold boot.

I'm I missing a setting that will allow SharpCap to sleep and recover with ZWO cameras?

I am able to disconnect the camera via SharpCap's "cameras" tool or turn on still mode. This allows the sleep and wakeup to work normally. However, it is not convenient and the consequence of forgetting and closing the laptop lid to sleep is a big reboot and restart of my entire setup.

I think this may be a ZWO driver issue. SharpCap is not alone have trouble sleeping when connected to a camera. Zwo's ASIStudio has the same trouble, for example.

Oddly, my SVBony camera allows windows to sleep and wakeup when SharpCap is running and connected. SharpCap resumes just where it left off when the computer wakes up.

Thanks for any ideas of how to troubleshoot this issue.

Peter

[admin]

Hi,

this isn't something I've every deliberately tried before (in fact, SharpCap has settings to allow it to prevent sleep mode from happening as that's often a problem for people who leave their imaging unattended).

Anyway, I tested here and just as you observed, sleep mode doesn't work properly for ZWO (and ToupTek) cameras - the monitors switch off, but the actual PC never goes to sleep. However SVBony (and Player One) cameras do allow the system to go to sleep while the camera is active.

I did find that just pressing a button on the keyboard seemed to bring the computer back from 'half asleep mode' - it woke up the display and I could continue (Win11).

I think I agree with your conclusion that because this affects some brands of camera but not others, and because it affects multiple software applications for the ZWO cameras, it's very likely to be a driver related issue. Maybe a device driver can block the computer going to sleep if it wants (I've never done any driver level development, so no experience to add there). I guess this is worth raising with ZWO if it is really important to you - if you do, it's best to describe the steps to reproduce using ASIStudio (and mention it happens in other applications like SharpCap too) - otherwise they might just try to bounce it back to me and I don't think I can do anything about it...

cheers,

Robin

[PeterAB]

Hello Robin,

Okay, I'll reach out to ZWO.

I just noticed that you are correct that any key press will recover Windows if my laptop is plugged in. If it is on batteries, it stays stuck until I do a long power button press to completely power down the laptop. It also appears that my laptops will timeout and power down on its own after an extended period of time. At any rate, this is not a SharpCap issue.

I may have an unusual observing style. Sometimes I observe visually with my 10 inch SCT on an old non-goto fork mount. I often have a small 50mm telescope mounted piggyback. The small telescope does double duty. It finds objects with the push to assistant. It also makes nice live stacked EAA style images The EAA images from the small telescope go much deeper than visual observations with the SCT, however the SCT has much better resolution.

I need to run on batteries at my dark observatory because it is off-grid (the reason why it is very dark). That is why I like to put my laptop to sleep when it is not working. Plus, shutting the laptop lid is the fastest way to make the laptop go dark. I have one eye patched when I'm using the laptop so that I'm ready to go visual as soon as the electronics are dark.

SharpCap is versatile and works well with my mixing of old and new equipment and observing styles.

Thanks again, Peter

[PeterAB]

Hi everyone,

A new observation on this issue. If my laptop set stuck trying to sleep with a ZWO camera running, I can unplug the USB cable to the camera and the laptop will immediately sleep correctly. Upon waking up, SharpCap will detect the camera has been disconnected and will reconnect when the camera is plugged backing.

Unplugging the USB cable is easier and faster and easier than doing a hard power down and cold boot with a recovery.

Thanks for helping me think through my issue.

Peter

[admin]

Hi Peter,

glad you have a workaround that (mostly) gives you what you need. I should point out that the reconnection handling in SharpCap that tries to detect that the camera has been reconnected and makes things just resume where they left off is on a 'best effort' basis, so will not be 100% reliable.

From the point of view of power at remote locations, 12V Lithium-Iron-Phosphate (LiFePO4) batteries have become remarkably cheap over the past year, particularly those aimed at leisure vehicle (RV) owners. These batteries tolerate deep discharge (to 90%), will protect themselves from over charge/over discharge and have a lifetime of up to 3000 cycles. They are also about half the weight of an equivalent lead-acid battery (which you can probably only discharge safely down to 50% anyway). They can obviously power normal 12V equipment nicely and you can easily get 'car laptop chargers' that take 12V and will convert to the correct voltage for your laptop.

cheers,

Robin