If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Rate Thread | Display Modes |
#16
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
On Tue, 15 May 2012 18:46:09 -0700, Gene E. Bloch wrote:
If it's true that the sunwait program is not robust in Windows, maybe it's possible to get the source and rejigger it in Java, if you don't have a C compiler. Here are some other programs that I found in Google. http://unix.stackexchange.com/questi...e-command-line http://sidstation.loudet.org/suntimes-en.xhtml http://sidstation.loudet.org/sunazimuth-en.xhtml http://unix.stackexchange.com/questi...e-command-line http://stenarson.com/projects/suncron/ http://ptaff.ca/crepyscule/api/publi...le-module.html Several are for *nix; the first two are for Windows and seem to be the same thing with different names (or vames :-) I tried the first one. It works, but its use and output are, IMO, clumsy. Also, the results are in UTC, so you'd have to convert the times (or use a fake longitude), if you could even extract them from the output... Given the large number of hits I saw for *nix, maybe you should consider using a server running some flavor of that. Now I'll go away before you get annoyed at all this stuff I keep throwing at you :-) -- Gene E. Bloch (Stumbling Bloch) |
Ads |
#17
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
On Tue, 15 May 2012 20:16:51 -0500, Char Jackson wrote:
On Tue, 15 May 2012 13:51:16 -0700, "Gene E. Bloch" wrote: On Tue, 15 May 2012 13:26:00 -0400, (PeteCresswell) wrote: Per Dave-UK: Could you not switch the camera on/off with a light-sensitive switch ? Sounds like a good fallback position - assuming the server handles the camera's going offline/online gracefully. It's powered via POE, so it would just be a matter of turning the POE switch off/on. Thanks! An alternative to that might be to have software that senses the state of the photocell and does a clean start and stop of the camera program. Luckily, I don't have to say how to do it :-) I *would* say it's possible. What comes to my mind is something like this: connect the photocell to an input line on a microcontroller, and have it communicate over USB to the computer to trigger the action. Talk about overkill :-) Let's Rube Goldberg it! :-) Great idea! Although I think I got pretty close already. -- Gene E. Bloch (Stumbling Bloch) |
#18
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
On Wed, 16 May 2012 18:23:15 +0100, Ed Cryer wrote:
(PeteCresswell) wrote: I've got an IP camera hooked into a server at a remote location. The server is FTP-ing a constant series to 20-second video clips to another location. Each clip is about a meg in size. So far, so good... Problem is that the camera goes nuts after dark and the clips come out to be 10-20 megs - basically of darkness with some lights on a distant shore. What I want to do is kill the server around sundown and start it up after sunrise. To that end, I'd need something to help scheduler out. So far, all I can come up with is http://www.risacher.org/sunwait/ Problem is that, although the developer has compiled it to a .EXE, it has not been tested - and it seems to have problems parsing the command line. So, bottom line: Does anybody know of a way to schedule jobs relative to sunrise/sunset? I've been hit by a wise thought while pondering on this matter. It is this. A problem has arisen, and we're all racking our brains for a solution, but we're drifting from the actual cause of the problem into its symptoms and offering solutions for those. Now then, the cause is quote "the camera goes nuts after dark.......". Solve that and the problem goes away. Is that the norm for this make? Can it be cured? Why does it take more space to deal with a dark world? Flash? My own digital cameras use less space when I take a snap in the dark. Ed In addition to what (PeteCresswell) said, consider that a dark and noisy signal is very random, so it won't compress well (no pun is intended on your name, Pete). That said, I thoroughly agree with what you said. To me, the best solution would be a camera that stops sending data when there isn't any useful stuff, or a camera that can be turned on & off by a photocell without disturbing the link-up. Or maybe some infrared lamps that are turned on when its dark, and provide enough light to solve the noise problem. Geez - I just promised Pete that I'd go away, and here I am again. Bad boy... -- Gene E. Bloch (Stumbling Bloch) |
#19
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
In message , Gene E. Bloch
writes: [] In addition to what (PeteCresswell) said, consider that a dark and noisy signal is very random, so it won't compress well (no pun is intended on your name, Pete). That said, I thoroughly agree with what you said. To me, the best solution would be a camera that stops sending data when there isn't any useful stuff, or a camera that can be turned on & off by a photocell without disturbing the link-up. Or maybe some infrared lamps that are turned on when its dark, and provide enough light to solve the noise problem. [] Or just turn off the camera's AGC - if it _can_ be turned off. I would be surprised if it _actually_ produces any more noise in the dark - it's just that the gain gets turned up. (Though these days I suspect the AGC is built in, and may not be disable-able.) -- J. P. Gilliver. UMRA: 1960/1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf once described by Eccentrica Golumbits as the best bang since the big one ... (first series, fit the second) |
#20
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
Per Ed Cryer:
I can't help but return to the webcam. Get one that doesn't have that fault; because it is a fault! Cams are pretty cheap these days. This one was close to a thousand bucks. IP-66 weatherproof, survivability outdoors in a salt-water environment, POE, a certain resolution..... Plus the fact that I went in to this knowing that 640x480 was not going tb adequate - but not knowing how high a rez we would really need. In retrospect, it's probably a certain degree of overkill now that I know that we could (maybe even will *have* to bco bandwidth limitations) probably use something with lower rez, but no way something like that is going tb cheap like the $80 640x480 FosCams I've been playing around with at home. I think the night noise thing is a red herring of my own making. Nobody cares what the cam is putting out at night, except for the high-volume videos that wind up clogging the FTP que. That was fixed in about 10 minutes with a couple of scheduled .BAT files. The Sunrise/Sunset thing was just a nice-to-have so the process would not require attention as the seasons change. Finally, I still would not rule out RCI on my part. Maybe there's a setting in the cam that would have mitigated the night noise. There are a *lot* of settings in this thing.... -) -- Pete Cresswell |
#21
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
On Wed, 16 May 2012 21:22:14 -0400, "(PeteCresswell)"
wrote: Per Ed Cryer: I can't help but return to the webcam. Get one that doesn't have that fault; because it is a fault! Cams are pretty cheap these days. This one was close to a thousand bucks. IP-66 weatherproof, survivability outdoors in a salt-water environment, POE, a certain resolution..... Plus the fact that I went in to this knowing that 640x480 was not going tb adequate - but not knowing how high a rez we would really need. This is a pretty nice outdoor camera for $299: http://gopro.com/cameras/hd-hero2-outdoor-edition/ This feature, "Live Streaming Video and Photos to the Web", is 'coming soon', so it's apparently not capable at the moment, unfortunately. My son uses a camera from the GoPro series and loves it. -- Char Jackson |
#22
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
(PeteCresswell) wrote:
Per Ed Cryer: I can't help but return to the webcam. Get one that doesn't have that fault; because it is a fault! Cams are pretty cheap these days. This one was close to a thousand bucks. IP-66 weatherproof, survivability outdoors in a salt-water environment, POE, a certain resolution..... Plus the fact that I went in to this knowing that 640x480 was not going tb adequate - but not knowing how high a rez we would really need. In retrospect, it's probably a certain degree of overkill now that I know that we could (maybe even will *have* to bco bandwidth limitations) probably use something with lower rez, but no way something like that is going tb cheap like the $80 640x480 FosCams I've been playing around with at home. I think the night noise thing is a red herring of my own making. Nobody cares what the cam is putting out at night, except for the high-volume videos that wind up clogging the FTP que. That was fixed in about 10 minutes with a couple of scheduled .BAT files. The Sunrise/Sunset thing was just a nice-to-have so the process would not require attention as the seasons change. Finally, I still would not rule out RCI on my part. Maybe there's a setting in the cam that would have mitigated the night noise. There are a *lot* of settings in this thing.... -) At a thousand bucks, it's possible the camera has a "day/night" IR filter, which can be switched in and out. IR filters are sometimes "fixed" on color cameras, to improve color balance in daylight. Surveillance cameras can have that filter set up on a shutter, so it can be move into or out of the optical path. When the IR filter is removed, and the user provides a LED based IR illuminator, it's possible to improve the nighttime noise situation. With the IR filter removed inside the camera (config setting), the IR illuminator can light up the scene. Cameras have a "noise floor", where you see random sparkling pixels under low light. If the camera captures in a compressed format. the sparkling pixels resist compression, and the file size (or streaming speed) increases. That could be what you're seeing. If the camera captured in an uncompressed format, then there'd be no difference between daytime and nighttime data rate. Good camera sensors use things like HAD. I don't think Sony will sell their HAD sensors to companies making web cams, and web cams just don't have the same qualities as these things do. But even with a technology like this, you still need illumination to make it work. http://en.wikipedia.org/wiki/Hole_Accumulation_Diode IR illuminators come in "light bulb + gel filter" type, or ones that are based on true IR LEDs. The IR LEDs emit far enough outside human visual range, that the illuminator would go undetected by the naked eye. (Perhaps you could "feel" the heat, but not see the light.) And the IR illuminator would only work well, if the IR filter is "switched out" on the camera (such as at night). http://www.supercircuits.com/Infrared-Illuminators/IR25 If I was a B&E specialist, and I drove to your site, I could "preview" the site with a camcorder, as the IR illuminator will show up in the camcorder view of the property. It's just the human eye that can't see them, whereas silicon sensors would be able to pick it up. And if I could detect the IR illuminator, then I'd know there was a camera present. Paul |
#23
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
Per Paul:
If I was a B&E specialist, and I drove to your site, I could "preview" the site with a camcorder, as the IR illuminator will show up in the camcorder view of the property. It's just the human eye that can't see them, whereas silicon sensors would be able to pick it up. And if I could detect the IR illuminator, then I'd know there was a camera present. Believe-it-or-not, it was early in the game when I stumbled on to the realization that I did *not* want IR at night. Not that I knew anything about the camcorder thing, of course.... But just from the red glow it seemed like it must be pretty obvious to the passing crackhead that there was an object up there worth stealing. It kind of wonders me that the standard IR illumination gives off that human-visible glow. -- Pete Cresswell |
#24
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
(PeteCresswell) wrote:
Per Paul: If I was a B&E specialist, and I drove to your site, I could "preview" the site with a camcorder, as the IR illuminator will show up in the camcorder view of the property. It's just the human eye that can't see them, whereas silicon sensors would be able to pick it up. And if I could detect the IR illuminator, then I'd know there was a camera present. Believe-it-or-not, it was early in the game when I stumbled on to the realization that I did *not* want IR at night. Not that I knew anything about the camcorder thing, of course.... But just from the red glow it seemed like it must be pretty obvious to the passing crackhead that there was an object up there worth stealing. It kind of wonders me that the standard IR illumination gives off that human-visible glow. The illuminator based on a light bulb plus a gel filter, the passband extends into the visible. This is a function of how effective the filter is, at removing visible light. IR LEDs on the other hand, emit at a specific wavelength (but the spectrum analyser plot is a bump rather than a vertical line). The center wavelength plus "shoulder" is supposed to be outside the human visual threshold. If you had an IR laser diode, then the spectral output of that would be a sharper line on a spectral plot. LEDs are "sloppy" on spectrum. (Page 3 here has an example. Central peak at 940nm and shoulder stops at around 980nm. LED suitable for a TV remote control. Some visible LEDs I've looked at in the past, had a 200nm wide bump. So the spectrum on this one, is relatively tight in terms of numbers of nm.) http://media.digikey.com/pdf/Data%20.../HSDL-4270.pdf Infrared illuminators use large numbers of LEDs like that. When I did a quick check, I don't see infrared LEDs available in the high power LED families used for illumination (1 watt or 5 watt LED). So a company making an illuminator, may need to use bunches of the small ones. That particular LED has a max of 100mA current, and you'd want to run it at somewhat less than that. One of the problems with LEDs for illumination (i.e. all those LED light bulb replacements at the store), is cooling. LEDs can't really take an elevated junction temperature. Which is why the LED light bulbs are shaped with cooling in mind. And putting the LED lightbulb into a traditional "enclosure" with no cooling, is bad for it. So when incandescent bulbs disappear, the replacement technologies are happier to be out in the open, for cooling reasons. While that LED in the above datasheet may have a 100mA rating, how close you can get to applying that current (and having a long life) may depend on the resulting junction temperature. So imagine a surveillance application "lit by 1000 TV remote controls", where you cannot see the light. In terms of seeing IR with a camcorder, there is another device you can get. Radioshack used to sell a card with an IR sensitive end on it. 276-1099. (I have one here.) You "charge" the card in visible light, like from an ordinary lamp. Then, hold items like your TV remote (using IR LED) next to the "brown end" of the card, then press a button on the remote. You can see the rate that the command burst on the remote is repeated by doing that. A "dot" of light sent by the remote, shows up in the brown area, as a visible glow. This is effectively a kind of "frequency shifting", and useful for testing remotes without digging for the camcorder. http://loisirflip.fr/Pinrepair/www.p...c/wpcopto2.jpg The pricing on these cards is ridiculous, presumably because not many companies make them. This one is $14.55. The Radio Shack one might have been $5 or so, and I still considered that to be a rip-off. http://www.mcmelectronics.com/produc...-6771-/72-6771 Paul |
#25
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
"Gene E. Bloch" wrote in
: On Tue, 15 May 2012 13:26:00 -0400, (PeteCresswell) wrote: Per Dave-UK: Could you not switch the camera on/off with a light-sensitive switch ? Sounds like a good fallback position - assuming the server handles the camera's going offline/online gracefully. It's powered via POE, so it would just be a matter of turning the POE switch off/on. Thanks! An alternative to that might be to have software that senses the state of the photocell and does a clean start and stop of the camera program. Luckily, I don't have to say how to do it :-) I *would* say it's possible. What comes to my mind is something like this: connect the photocell to an input line on a microcontroller, and have it communicate over USB to the computer to trigger the action. Talk about overkill :-) Yes....over kill. On the right track, just not KISS-compliant..... If the PC has a (RS232) serial port, you could easily connect the photocell to the CTS input through a resistor divider, or a pot wired as a resistor divider, and set it for the amount of light needed to assert CTS. A very small and simple VB program could be written to start/stop the camera program as necessary. (There's usually some level of hysteresis on a PC serial port, but if necessary, a logic chip w/hysteresis could be used as a buffer. |
#26
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
On Thu, 17 May 2012 13:43:22 -0500, DanS
wrote: "Gene E. Bloch" wrote in : On Tue, 15 May 2012 13:26:00 -0400, (PeteCresswell) wrote: Per Dave-UK: Could you not switch the camera on/off with a light-sensitive switch ? Sounds like a good fallback position - assuming the server handles the camera's going offline/online gracefully. It's powered via POE, so it would just be a matter of turning the POE switch off/on. Thanks! An alternative to that might be to have software that senses the state of the photocell and does a clean start and stop of the camera program. Luckily, I don't have to say how to do it :-) I *would* say it's possible. What comes to my mind is something like this: connect the photocell to an input line on a microcontroller, and have it communicate over USB to the computer to trigger the action. Talk about overkill :-) Yes....over kill. On the right track, just not KISS-compliant..... If the PC has a (RS232) serial port, you could easily connect the photocell to the CTS input through a resistor divider, or a pot wired as a resistor divider, and set it for the amount of light needed to assert CTS. A very small and simple VB program could be written to start/stop the camera program as necessary. (There's usually some level of hysteresis on a PC serial port, but if necessary, a logic chip w/hysteresis could be used as a buffer. Hmm, nice, but I'd still prefer to see a solution that includes a golf ball dropping on a mouse trap. Extra points for including a series of toppling dominoes. ;-) Not dissing your solution, just having fun. -- Char Jackson |
#27
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
DanS wrote:
"Gene E. Bloch" wrote in : On Tue, 15 May 2012 13:26:00 -0400, (PeteCresswell) wrote: Per Dave-UK: Could you not switch the camera on/off with a light-sensitive switch ? Sounds like a good fallback position - assuming the server handles the camera's going offline/online gracefully. It's powered via POE, so it would just be a matter of turning the POE switch off/on. Thanks! An alternative to that might be to have software that senses the state of the photocell and does a clean start and stop of the camera program. Luckily, I don't have to say how to do it :-) I *would* say it's possible. What comes to my mind is something like this: connect the photocell to an input line on a microcontroller, and have it communicate over USB to the computer to trigger the action. Talk about overkill :-) Yes....over kill. On the right track, just not KISS-compliant..... If the PC has a (RS232) serial port, you could easily connect the photocell to the CTS input through a resistor divider, or a pot wired as a resistor divider, and set it for the amount of light needed to assert CTS. A very small and simple VB program could be written to start/stop the camera program as necessary. (There's usually some level of hysteresis on a PC serial port, but if necessary, a logic chip w/hysteresis could be used as a buffer. This is an example of another way to do it. This is a USB to byte-wide logic input chip, with synchronous and asynchronous options. Perhaps you could cook up a logic input with something like this (if the SDK is easy to use). http://www.ftdichip.com/Products/ICs/FT245R.htm Using the part number, you can find little development boards with the chip on it. The "FT245 TinyBoard" being the first hit in a search engine. http://www.oxisso.com/Misc/index.html In previous times, a PCI card with buffers might have been used to do a similar thing. But now, there are USB devices for home projects. Paul |
#28
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
In message , Paul
writes: (PeteCresswell) wrote: [] It kind of wonders me that the standard IR illumination gives off that human-visible glow. The illuminator based on a light bulb plus a gel filter, the passband extends into the visible. This is a function of how effective the filter is, at removing visible light. IR LEDs on the other hand, emit at a specific wavelength (but the spectrum analyser plot is a bump rather than a vertical line). The center wavelength plus "shoulder" is supposed to be outside the human visual threshold. Well it isn't. Every camera I've played with that claims to have night vision (and I'm sure does) by using IR LEDs, has ones which make a perfectly visible red glow; as Pete says, it seems odd that they are. [] So imagine a surveillance application "lit by 1000 TV remote controls", where you cannot see the light. I'm not sure if remotes use truly non-visible ones, or just sufficiently low power that you wouldn't anyway: a lot of them also seem to have a filter (which looks black to us). Though I've just tried my nearest one (which doesn't have a filter) and I can't see it at all. [] -- J. P. Gilliver. UMRA: 1960/1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf What would be unusual would be if there weren't any coincidences at all for several days in a row. Andy Roberts (UMRAt), 23rd. October 1998. |
#29
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
Char Jackson wrote in
: On Thu, 17 May 2012 13:43:22 -0500, DanS wrote: "Gene E. Bloch" wrote in : On Tue, 15 May 2012 13:26:00 -0400, (PeteCresswell) wrote: Per Dave-UK: Could you not switch the camera on/off with a light-sensitive switch ? Sounds like a good fallback position - assuming the server handles the camera's going offline/online gracefully. It's powered via POE, so it would just be a matter of turning the POE switch off/on. Thanks! An alternative to that might be to have software that senses the state of the photocell and does a clean start and stop of the camera program. Luckily, I don't have to say how to do it :-) I *would* say it's possible. What comes to my mind is something like this: connect the photocell to an input line on a microcontroller, and have it communicate over USB to the computer to trigger the action. Talk about overkill :-) Yes....over kill. On the right track, just not KISS-compliant..... If the PC has a (RS232) serial port, you could easily connect the photocell to the CTS input through a resistor divider, or a pot wired as a resistor divider, and set it for the amount of light needed to assert CTS. A very small and simple VB program could be written to start/stop the camera program as necessary. (There's usually some level of hysteresis on a PC serial port, but if necessary, a logic chip w/hysteresis could be used as a buffer. Hmm, nice, but I'd still prefer to see a solution that includes a golf ball dropping on a mouse trap. Extra points for including a series of toppling dominoes. ;-) Not dissing your solution, just having fun. I removed the golf ball/mouse trap and dominoes when I saw it would take 100 times the complexity to mechanically reset all that stuff each day, twice a day. |
#30
|
|||
|
|||
Scheduling Relative To Sunrise/Sunset?
Per J. P. Gilliver (John):
. Every camera I've played with that claims to have night vision (and I'm sure does) by using IR LEDs, has ones which make a perfectly visible red glow; as Pete says, it seems odd that they are. I've read references to IRs that emit on a different freq that is not visible to the human eye. In fact, I've got a game camera that takes still photos whose flash is not visible. Must be some logical reason why they use the visible freq on most surveillance cams... but what? Cost? Efficiency? -- Pete Cresswell |
Thread Tools | |
Display Modes | Rate This Thread |
|
|