Jump to content


ebuild is sad to announce its closure - it has become too time and resource intensive to develop, manage and maintain.

However, ebuild will remain on-line in archive mode (ie no posting facilties) for several weeks so that users can use it as an information resource.

More Pi


  • Please log in to reply
109 replies to this topic

#1 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 07 April 2014 - 06:13 PM

Looks like an interesting new development from the Pi people. It's a board new PCB design with the same processing power but more IO. Just the thing for monitoring the house, and wasting huge amounts of time in the winter evenings.

http://www.raspberry...le-new-product/

#2 DamonHD

DamonHD

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,046 posts
  • LocationLondon, UK

Posted 07 April 2014 - 07:06 PM

Yes, I would certainly consider one of those as the Internet gateway from OpenTRV for example, since thought is explicitly being given to more robust and compact packaging. We could drop it on a board with one of our units to make a complete hub quite easily I imagine.

Rgds

Damon

#3 pocster

pocster

    Regular Member

  • Members
  • PipPipPip
  • 712 posts

Posted 08 April 2014 - 03:33 PM

Nice!

#4 TerryE

TerryE

    Regular Member

  • Member Blogger
  • PipPipPip
  • 709 posts
  • LocationSouth Northants

Posted 26 May 2014 - 10:05 AM

Hummnnnn, I've got a Raspberry_Pi, and I really like the concept, price point, etc., but IMO it has a fundamental Achilles heel, and that is the choice of the ARM chip at its heart is a Broadcom BCM2835 chip which is a closed-source ARMv6 CPU that was designed about 10 years ago to support the then mobiles. This means that (i) a lot of CHIP details can't be published openly; (ii) it is very slow compared to current alternatives; (iii) mainstream Linux releases such as Ubuntu no longer support ARMv6 and hence it.

This board compute board is a repackaging which doesn't address any of these points. I am seriously looking at the BeagleBone Black which I feel addresses all of these points, and is available through RS etc at only a little more cost, but rather than discuss pros and cons here, this Maker Corner blog post does a better job: Choosing between the Raspberry Pi or BeagleBone Black

Edited by TerryE, 26 May 2014 - 10:05 AM.


#5 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 26 May 2014 - 11:06 AM

I am not sure there is much to choose between the Pi or the Beagle, but to answer your points...

i) Unfortunately the blog is out of date. Broadcom released a lot more info a month or so ago, take a look at http://www.raspberry...from-broadcom/. There are still chunks of the multi-media processor that are undocumented (HDMI etc) but nothing that is likely to be an issue for general IO handling.

ii) The Pi scales from very slow up to around 1GHz in "turbo mode", personally I'm far more interested in low power consumption than high performance for the applications I am using it for. I don't think the BeagleBone Black is much faster, you probably need to be looking elsewhere if you need serious performance.

iii) Whether this is an issue depends very much on your target application, I certainly wouldn't want to be running full fat Ubuntu on a data acquisition board. I tend to run a stripped down Debian variant with all access via SSH (no graphics).

#6 DamonHD

DamonHD

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,046 posts
  • LocationLondon, UK

Posted 26 May 2014 - 12:13 PM

If you really want low-power data acquisition nodes consider something like a modified Arduino; mine consumes microwatts (well, tens of microwatts including radio transmission of stats) and then store those stats elsewhere (eg on a central RPi or BBB).

Power consumption of all the nodes involved here, mains or battery powered, is too low for me to easily measure in the field; data is being gathered by my ~4W SheevaPlug (no graphics, SSH access, powered off-grid with PV).

http://www.earth.org...isensortemp.png

Rgds

Damon

Edited by DamonHD, 26 May 2014 - 12:14 PM.


#7 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 26 May 2014 - 02:22 PM

I have used the 8-bit Arduino boards in the past, they are at far lower power/performance point than the Pi (although similarly priced). This makes them a great choice for remote acquisition, I may well end up using them in this role in the new build.

It's great to have such a wide choice at the moment, a few years ago there was almost nothing affordable in the market.

#8 DamonHD

DamonHD

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,046 posts
  • LocationLondon, UK

Posted 26 May 2014 - 03:30 PM

Indeed, and it's miraculous compared to what was available 25--30 years again when I was getting started!

Rgds

Damon

#9 TerryE

TerryE

    Regular Member

  • Member Blogger
  • PipPipPip
  • 709 posts
  • LocationSouth Northants

Posted 26 May 2014 - 03:46 PM

@Alphonsox, OK Broadcom have now just released the graphic core under a BSD licence, but as you say you'd want to run headless anyway for this sort of application. The article is still pretty much in date as a general comparison. I've done a bit of server work over the years to cloud-based VMs "in the cloud" or behind corporate firewalls, so I am at home with SSH to a headless config. I also contribute to PHP internals (and other FLOSS packages in the past) so I am pretty familiar with configuring and building packages from source, but there's nothing so convenient as just doing an apt-get install to fetch something that you need, and that means you need a distro with a pretty complete package set. That's the main advantage of using a ARMv7 CPU and Ubuntu server, IMO, but I need to take another look at the Pi package libraries.

I also agree that for this sort of app, keeping the control device pretty lean is the best way to go.

It is the integration with all of the instrumentation and controls that going to be the main complicating factor, as I see it, so sticking an Arduino setup in might be a good option as both Damon and you suggest.

@Damon, BTW, I had a look through your www.earth.org.uk site. What great resource!!! Thanks for this.

#10 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 26 May 2014 - 04:20 PM

I have not found anything significant missing from the available packages, apt-get seems to work without issue within the limited range of apps I have been using.

The main plus see with the graphics core now being documented is that it opens up the Pi to (some) DSP applications. There is already a good FFT library available, general purpose filters should be following soon.

#11 DamonHD

DamonHD

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,046 posts
  • LocationLondon, UK

Posted 23 June 2014 - 04:51 PM

Just bought an RPi and got it up and running and I am quite hopeful that I can replace my nearly-5-year-old SheevaPlug with it and save some more juice.

Will also order the DIMM board kit when RS has helped me out on a few technical queries.

I have to put some kind of battery-backed RTC (Real-Time Clock) on there for my purposes, so have splashed out about a tenner on one of those.

A nice 128GB SD card to get all my file systems on to is going to cost many time the RPi itself though!

Rgds

Damon

PS. Was a bit of a flashback sitting with it plugged into the family TV to set up, though this time with my kids not my parents!

Edited by DamonHD, 23 June 2014 - 05:43 PM.


#12 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 23 June 2014 - 05:33 PM

View PostDamonHD, on 23 June 2014 - 04:51 PM, said:

PS. Was a bit of a flashback sitting with it plugged into the family TV to set up, though this time with my kids not my parents!

I know exactly what you mean - This time it was the Pi plugged into my 50 inch Sony flat screen, 33 years ago it was my home built ZX81 plugged into my dad's rented Rediffussion. :)

Edited by Alphonsox, 23 June 2014 - 05:33 PM.


#13 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 14 July 2014 - 01:01 PM

Another slice available......

Lower power, more USB, More GPIO, micro SD, decent mount holes

http://www.raspberry...pi-model-b-plus

#14 SteamyTea

SteamyTea

    Advanced Member

  • Members
  • PipPipPipPip
  • 4,322 posts
  • LocationCornwall

Posted 14 July 2014 - 07:21 PM

Been using my Pi for over a year now, think I measured it at 1W, so virtually nothing.
I use it to log the data from my CurrentCost Envi, which I power off the Pi's 3.3V pin.
Other things I have done are running some 1-wire temp sensors, some DHT11 temp/RH sensors, my LabJack U3HV (powered from the USB). Made a timelapse camera, a wireless print server and an RC logger (thats Resistance/Capacitance not Radio Control).
I have used it as a media centre, but just never used it enough, worked well though.

The two main criticisms I have of the Pi are the lack of a real time clock and analogue ports (hence the LabJack and the RC logger).
Oh and the lack of USB ports.

I found a useful bit of software called Win32 Raspbian WiFi Injector, allows the SD card to have your network/router settings written to it before first boot, can run it headless from the start then, no playing about with messy cables.

I still find Linux, especially from the command line, a game of pure luck though. apt-get autoclean is useful.

Edited by SteamyTea, 14 July 2014 - 07:22 PM.


#15 jsharris

jsharris

    Please ignore all posts by me, some are erroneous

  • Member Blogger
  • PipPipPipPip
  • 11,461 posts
  • LocationWiltshire/Dorset border

Posted 14 July 2014 - 07:38 PM

View PostSteamyTea, on 14 July 2014 - 07:21 PM, said:

I still find Linux, especially from the command line, a game of pure luck though. apt-get autoclean is useful.

That's my main issue, but I am typing this on a Linux laptop. On the plus side, on higher end machines Linux starts in a couple of seconds and is very much faster at everything than Windows (although this is a reasonably quick i7 machine, so probably overkill for running Linux Mint).

#16 SteamyTea

SteamyTea

    Advanced Member

  • Members
  • PipPipPipPip
  • 4,322 posts
  • LocationCornwall

Posted 14 July 2014 - 07:58 PM

Using Linux with a GUI is pretty painless for most things (I still have a soft spot for Puppy), what gets tricky is knowing what is available and what it is capable of.

And I wish Calc in Libra Office used the same keystrokes as Excel when it comes to doing relative referencing and array calculations. Though that is not really a Linux issue.

The file structure is dreadful to an old DOS user, does it really need so many partitions and oddly named directories. I know some of it was done for security/reliability reasons, but for a user that is transferring over it is really confusing.

#17 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 14 July 2014 - 08:05 PM

I have been using command line Unix/Linux professionally for 20+ years and have almost got the hang of it. It allow you to do things that you can only dream of from the GUI, well worth taking some time to play with. Although as you've noticed its by no means intuitive and seems to be based as much on historic accident as careful planning.

#18 DamonHD

DamonHD

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,046 posts
  • LocationLondon, UK

Posted 14 July 2014 - 11:59 PM

Have you all noticed the new RPi Model B+ out today/yesterday? Some extra I/O and better (more efficient) power supply, which should really get consumption down to ~1W.

I have one one order to save me hacking off the linear reg on a normal model B.

Plus I got my high-side power monitor working, though measuring the SheevaPlug rather than itself for now:

http://www.earth.org...grid-stats.html

Rgds

Damon

PS. Historical accident? B^|> The *nix command line is still much as it was when I first ran across it not quite 30 years ago. tar tvf and ps [-]guaxww and for f in u mate; do it; done are just as pertinent as they were then!

Edited by DamonHD, 15 July 2014 - 12:05 AM.


#19 Alphonsox

Alphonsox

    Advanced Member

  • Members
  • PipPipPipPip
  • 1,495 posts
  • LocationCounty Down, NI and Forest of Dean, England

Posted 15 July 2014 - 11:16 AM

View PostAlphonsox, on 14 July 2014 - 01:01 PM, said:

Another slice available......

Lower power, more USB, More GPIO, micro SD, decent mount holes

http://www.raspberry...pi-model-b-plus

In case anyone has been waiting to take a plunge into Pi land Aria are selling off their model-B boards for £18.
http://www.aria.co.u...ewsletter150714

Edited by Alphonsox, 15 July 2014 - 11:16 AM.


#20 SteamyTea

SteamyTea

    Advanced Member

  • Members
  • PipPipPipPip
  • 4,322 posts
  • LocationCornwall

Posted 15 July 2014 - 02:49 PM

Don't think I will buy anymore, got 3 of the critters infront of me at the moment, and more scattered around the countryside :rolleyes:

A good book on Python and C may be useful though