Home Automation Domotica Forum Europe, Bwired Forum

Hi all,

My current HA pc, based on a via mini-itx board, is coming apart: it has become unstable and as I've not been very satisfied with its performance, I don't want to spend time on fixing it anymore.

Last week, I looked into laptops, as I'm looking for a low power solution and like the idea of getting a UPS and screen into the deal "for free". Laptops are hard to beat, if power consumption is considered.

I saw an interesting offer for a new HP business laptop (type 6720s), based on a Celeron M530 processor running @ 1,73 GHz. It has all the basic features you'd expect (LAN+WLAN, 120Gb 5400rpm disk, DVD writer, 15,4" 1280x800 widescreen), except for memory which is just 1024Mb (but easily upgradeable to 2 Gb for just 30 euros). It comes with Vista Home Basic (so no Aero, but given the on-board graphics, that could be considered a plus . Price for the whole thing: EUR 399,- including VAT. It appears HP is dumping these on the market as "end of life" models.

My questions:

- How would the Celeron M processor perform, escpecially compared to more powerful processors such as the (lower range) Core Duo T models? Would it make more sense to shell out another EUR 200,- to get a the same model with a T5470 @ 1,6 GHz? (Note that EUR 200 is 50% extra...)

- I'd like to run Homeseer (with Rfxcom plugin and logging of devices to a database), MySQL, Apache and PHP, and use it as a (mp3) file server for my home network. Would this laptop be powerful enough to be responsive?

- Should I wipe Vista Basic and install something else (Windows server 2003, Windows Home server, Windows server 2008, or even XP pro or Vista Business)? What would you recommend?

- I need a stable USB -> RS232 (or even PCMCIA -> RS232) solution as well for the Xanura CTX35. What would you recommend?

I'm looking for low power, stability (I hate things that work sometimes) and acceptable (but not high) performance, dedicated to HA/basic file serving. So, what do you think? Would this laptop be a good decision?

Thanks in advance for your thoughts!

Lennart

Hi Lennart,

I would say: anything capable of running Vista should also be able to run a HA app and AMP without much trouble...i would not use the 200 for more processing power. (see further on)
Main concern would be the harddisk i guess.

Personally i would install a less "hungry" OS. You don't need Vista for a dedicated HA system. But be sure you can get all drivers needed for the OS you wish to use. I once wiped Vista from a Toshiba notebook and then discovering there were no XP drivers for that model...

USB -> RS232: i would try to get everything connected to your LAN.
For example as i did with the serial interface for PTZ on one of my cameras: i had a RFXCOM LAN Interface, put a Serial module in it and connected my camera to that. Works flawlessly.
I have additional RFXCOM stuff, all of this is going to be attached to my LAN, so i will not have the need for USB or RS232 anymore.

There are many other ways of Ethernet-enabling devices that need USB or RS232. (spend those 200 here [:)])

Agree with Digit. I think the laptop will do fine if you replace Vista for XP or Windows 2003 server. Depends if you want to run IIS for outside usage as well (visitors). Take the GB mem for that price. Little worried about the MP3 streaming depends on which program you use for it.
Did you look at the small PC's from HP or Acer, also low on power and a bit better to handle then a laptop. As I read your topic you won't be walking around with it
regards Pieter

My advice will be run it virtual.
This will give you lot of flexibility.
You can run it from any PC or laptop.

Most of the VM software is for free.
Like
Vmwareserver (Vmware)
VirtualPC (MS)
virtualbox (innotek)
XEN.

When there is any problem i can even run my HA server on my Imac.

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by lennart</i>
<br />
- Should I wipe Vista Basic and install something else (Windows server 2003, Windows Home server, Windows server 2008, or even XP pro or Vista Business)? What would you recommend?
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">Keep in mind or don't forget that the 'new' license for these operating systems almost costs as much (if not more) than the 'server' itself. [:(] Except if you allready have them. [;)]

linux? [;)] 0,- euro. Ok granted , still doesn't do what i want, but is coming along.

// Erik (binkey.nl)

Thanks all, for your comments. I decided to get a dedicated home automation laptop (a little more horsepower than a Celeron, but still affordable), but I have two additional concerns when thinking it through:

1) Dust.

2) Heat.

To start with concern 1: fans tend to clog up with dust after some time, especially when used 24/7. Laptop fans are not that easy to replace. Any ideas on how to solve this?

As for concern 2: are laptops thermally designed to run 24/7? Concern 2 is related to 1, as getting rid of excess heat would mean forced cooling, which would mean more fans (laptop cooling pad with build in fans, for example) and thus more dust.

Thanks in advance!

Lennart

well it is a laptop, you never see a laptop in a server rack. So they are not designed to work 24/7 , that said dont forget if your not using it and not using the screen it will not get more temperature because it does not need to generate a picture. There are a couple of extra fans you can get make sure that you put the laptop tilded, so that underneath it still has a airflow.

See next example, what i mean with tilted.. (and also extra fan)



// Erik (binkey.nl)

Lennart,

1, the Dust.
That's a hard question to answer. All i can tell you i have an old laptop here, 4 years old, that needed more and more cooling as it got older. I blame it to the dust gathering around the cooling elements. I don't see any other reason. And i don't have any good tips on how to avoid this, actually...

2. Heat (also a nice movie, BTW).
I would think that, with relatively low load, any PC or laptop or anything else will reach some kind of "balance" regarding temperatures of its components in a relatively short time. When i look at my own HA application, it takes an average of 0.4% CPU (on a AMD Athlon 2400+). That's nothing. So i wouldn't care much about overheating your laptop; when it's able to run for 1 hour without overheating, it will continue to do so.

Well,

I use already for my website, and also domotica an dellp3 laptop (c400).

If you use an os like linux you can install a Lamp (linux Apache Mysql PHP), wich is secure, and you also need some mem (512mb) and it#347; very stable. With some domotica on it x10 and rfxcom the usage is very low.

you can use pcmcia card with 2 serial for example, but usb2serial works also ok.

Als what you can consider is use al simple desktop/laptop, that does the site, and on the backgorund a simple amd geode lx (around 5 watt) where you put all the domotica on it, when the website crashes you domotica still works. A kind of dmz principal

Hi all,

Thanks again for your replies regarding heat and dust. I think I have a solution that meets my requirements.

I decided to build a simple encasing for the laptop myself, using an aluminium flightcase as available from any hardware store. For cooling, I made two 78 mm holes in it at both sides and put an 80mm 12V case fan in front of each of the holes on the outside (one as inlet, one as outlet). (I chose the outside to have enough space left on the inside for the laptop .

Furthermore, I did some minor modifications for running cables through the side of the flightcase and raising the laptop inside of the flightcase, so the airflow mainly cools the bottom of the laptop. I paid attention to the ventilation inlets and outlets of the laptop itself and positioned the flightcase fans accordingly to get an optimal airflow. I also used a sealant to prevent air leakages.

To prevent dust, I put a filter in front of the fan that serves as an inlet. The filter is currently just a regular vaccuum cleaner motor filter. Although the filter does work, I noticed that it lowers the airflow considerably, so I just ordered some "official" case fan filters, as supplied by Azerty (http://www.azerty.nl/8-283/fanfilter.html), which seem to be less obstructive. I will try several (AC Ryan, Akasa, Nexus) to see which one gives best results.

I might also put a filter in front of the fan that serves an an outlet. Although this is not required for dust prevention, it does make both fans have the same airflow (m^3/hour) and thus prevents a vaccuum build-up inside of the flightcase that may suck in dusty air through any remaining splits/small holes.

Here are some pictures of the result:

Flightcase, opened:



Flightcase, closed, inlet fan:



Flightcase, closed, exhaust fan:



The three cables running through the side are the laptop power supply, ethernet and usb to a Xanura PMIX35 (but I'm probably going to virtualize the latter by using an RFXCOM ethernet interface + RS232 serial interface and my good old CTX35; the PMIX will then be used for testing purposes on my development machine).

The laptop is running Vista Business. I know, as you said, it's overkill, but I found a nice affordable laptop with some extra horsepower (Core 2 Duo T8100), and coming from a very slow, underpowered instable VIA mini-itx server, it feels right to have some spare CPU cycles left .

Beside running Homeseer, it serves as my fileserver, downloadserver and musicserver for our Sonos system, and also has WAMP server installed for some additional (private only) webpages/scripting. For remote access I installed an SSH daemon and use tunneling/client-to-server port forwarding on top of SSH to access all other services (such as SFTP and Remote desktop). Using public/private keys for access and only opening up port 22 inbound in my router/firewall should be sufficientlty secure (hopefully . The tunneling/client-to-server port forwarding also gives me direct access to my Axis network cameras, if needed.

As far as temperatures are considered: I used 3 Oregeon Scientific sensors to measure temperatures for some time. I put one in the room where the server is located. This is also the room where the washing machine, dryer, central heater and solar panel inverters are located, so ambient temperatures are kind of high (between 25 to 29 degrees, but more or less stable thanks to the mechanical ventilation of this room). I put another sensor inside of the flightcase, next to the laptop and one on the outside, in the fan air exhaust. Here's a graph of the temperatures on a typical day:



Red is ambient room temperature. Green is temperature inside of the flightcase and blue is flighcase fan exhaust temperature. It turns out that the exhaust temperature is 1.5 to 2.0 degrees C higher than ambient temperature, which looks fine to me.

The laptop consumes between 14 and 26 Watt, depending on load, with the screen turned off (as is usually the case). The two fans add another 2 Watt each. I did try running the fans at 5 Volt; these are Zalman ZM-F1 fans that are capable of running (and more importantlty starting up) at 5 Volt as well, which has the additional benefit that the fans could be powered through the USB bus (power consumption of each fan is 0.7 Watt at 5V), preventing adapter loss, but concluded that the resulting airflow was inadequate: exhaust fan temperatures rose to more than 7 degrees C above ambient temperature. I will retry this option with the other fan filters; maybe the airflow will be sufficient with these less obstructive filters.

Now we'll just have to wait and see if it still works in a few years time .

Lennart

Nice job Lennart!
I really liked reading your follow-up on this topic.
I think this will encourage a lot of others to do something equal to what you did. In the past i've also considered using a laptop for dealing with all the HA things, but in the end chose for virtualization on my new server. It's running at 65W, replacing >200W on old machines. The first of those old machines was shut down last weekend, 2 more to go..[:)]