Pi-Eyed

Since changing my weather station monitoring software from Weewx to Cumulus (see Weather Report) my Raspberry Pi has been a forlorn object, nestling dejectedly on a shelf against its redundant power supply. It had worked flawlessly without a reboot for weeks on end and for this its reward was to be cast aside.

My original plan for its reuse was as a DAC; the Pi's lackluster native sound handling being bolstered by adding a HiFiBerry DAC. There's a DAC+ for the Model A+ and B+ and a DAC that works with Model As and Bs with a P5 connector, '...that old Revision 1 versions don't have'. What luck, I have an early Revision 1 Model B. On to Plan B, then.

 Second Stage Lensman

For some time I've owned a Raspberry Pi camera which recently has been stored in its box on the same shelf as the Pi. Many and great are the applications for which people have used this device; my requirements, to use it as a webcam, were somewhat humbler. It's trivial to do this - typing:

raspistill -w 800 -h 600 -o /home/pi/webcam/picture.jpg

into the terminal causes a jpeg image called picture.jpg 800 by 600 pixels to be output to the folder /home/pi/webcam. And if the following line is added to crontab:

*/10 * * * * raspistill -w 800 -h 600 -o /home/pi/webcam/picture.jpg

the image is output every 10 minutes.

By increasing the rate the picture is taken and then streaming the image you can use it as a simple security camera.

There were two reasons I hadn't continued to use the camera; firstly, I had issues with it running with Weewx, possibly because I have an early version of the Pi, with only 256Mb of memory (in fairness I had similar problems with a Logitech C270 webcam). Secondly, as you can see from the picture below, the design of the camera is pretty basic; in essence it's just a lens and sensor on a small PCB attached to a short ribbon cable. This makes it awkward to use as it stands: its surface mounted components are unprotected and the ribbon cable is too short. Again, to be fair, the camera is meant to be used in projects, rather than be a finished consumer item.

A Raspberry Pi and its Camera

Mounting Climbing

I realised that to use the camera for any length of time without damage it would be sensible to find a way of mounting it; the blob of Blu-tack I had been using just wasn't up to the job. A search for 'Raspberry Pi camera mount' didn't bring up a huge number of novel and innovative products, surprisingly. The cheapest, simplest and arguably the best is the Pimoroni mount (£3, plus £3 postage - what!), which is essentially two bits of plastic and four plastic screws. At the other end of the scale is the all-in-one Pi and camera enclosure from Nwazet - a snip at £25.

The Nwazet gave me the idea that I could adapt the case I already had. This is a cheap, clear plastic object - unpretentious, but has fulfilled its purpose perfectly. And indeed I wasn't the first to have this idea with the very same type of case. Instead of double-sided tape (good grade!) I decided to use screws to fix the camera to the lid. Using the camera as a template I marked the position for four holes, then drilled them. Here's the first two:

First two of four holes drilled in case, top left.

I decided to make a square hole for the lens assembly so it would poke through the case. This probably made things unnecessarily complicated when a simple, single drilled hole would have served equally well. Measuring the position for the lens was awkward and I eventually created a paper template and used it to mark the outline of the lens hole. Cutting out the hole was achieved by drilling through the case at the four corners and using a small router bit in a electric mini drill to cut the plastic between them. Take my advice - just drill a round hole big enough for the lens assembly...

Square holes are more trouble than they're worth

The pre-drilled holes in the camera circuit board are only 2mm in diameter and even the smallest bolts I could find were too big. Widening the holes was a non-starter as there are wiring tracks that run very close to the edge of a couple of them, so I had to buy some nuts and bolts from a model shop in the local town. The reaction to my request for size M2 nuts and bolts was scornful, 'We only stock BA sized fixings.'. I admitted that these Imperial sized bolts would be far superior to the metric rubbish and the chap helpfully measured one with a micrometer to make sure they would be OK - you don't receive that sort of service when shopping online.

They were a tight fit, but fit they did and I tightened them carefully so I didn't crack the case. The finished result isn't too shabby: the camera is protected and is now a single unit with the Pi itself, making it look not unlike a digital camera.

The Golden Age of British engineering is still with us.

Now, how can I mount the Pi's case on a tripod...?

Weather Report

My weather station has been running virtually without a hitch for several months. The few problems I had encountered with the weewx software running on the Raspberry Pi had been ironed out (due to my errors, not the software's - see posts passim). The Pi has occasionally frozen and needed a reboot, but for a £30 device running 24/7 for months on end that's remarkable. It would be stupid to mess with it; best leave well alone now it's stable.


A Silver Lining in Every Cloud

No, of course I couldn't leave it alone. About two years ago I had a Maplin weather station feeding data to Sandaysoft's Cumulus software that was running on a Windows PC (see Where's the Time Gone). Whilst I liked Cumulus I wasn't prepared to leave the PC running in order for it to upload regular updates to the website, due to the noise it generated and the power it consumed, which is why I moved to the Pi. I always wanted to use Cumulus again and had considered building a mini PC using a low-power CPU and mini-ITX board. However, although mini-ITX motherboards are relatively cheap, by the time a hard drive, memory, a case and Windows, annoyingly the most costly component of all, had been added, the total cost had become eye-watering.

That would have remained the status quo were it not for my daughter complaining that her laptop had starting misbehaving: a blue screen of death that ultimately required a restore from a backup. Then the 'e' key stopped working; which causd hr quit a problm as it's th most common lttr in th languag. My suggestion of only using words without an 'e' didn't go down well and she resorted to using an on-screen keyboard until her new laptop arrived.

There are no problems, only opportunities, as some management wnkers (sorry, the 'a' key's playing up now) are wont to say. I realised I could use her old laptop as a way to run Cumulus; it would be quiet and fairly frugal with power too. Better still it had a large hard drive so it could also be utilised as a media server.

Cloud processing - Laptop running Cumulus software

Speculate to a Cumulus

After I had rebuilt the laptop from the factory image (then removed the cruft and bloatware that was included - I'm talking about you, Dell) I downloaded the latest version of Cumulus, 1.9.4 build 1085, from the Sandaysoft website. Cumulus is donationware: free to download and use, but you're encouraged to give the author some money to at least keep him in tea and biscuits. Considering the polished nature of the software, its features and the level of support that Steve, the author, provides it would be churlish not to donate something (I have). Although judging from a couple of justifiably testy comments Steve has made in the forum, many people are too cheap to do so (but probably still expect him to sort out their problems).

Like any weather software worth its salt, Cumulus doesn't just provide a regularly updated display of information from the weather station, it also includes FTP to allow the data to be uploaded to a website. A set of quite attractive web pages are provided (although the graphs are rather ugly) and the tags (used by Cumulus to embed the weather data into the web pages) are documented so you use the ones you want and design your own web pages. Simply put, to create the web pages the program uses template pages that it processes by embedding the tag data and then FTPing the resulting page. So, for example, the tag #temp is replaced by the temperature reading from the weather station. The Webtags page in the Wiki explains this in some detail.

There isn't a manual for Cumulus but there are a fairly comprehensive set of instructions on the Cumulus Wiki, plus there's a forum that's well frequented by knowledgeable weather enthusiasts and Cumulus users.

Once again I used the web server on my trusty old QNAP NAS to make the information available to the whole wide world. And if that wasn't enough, regular updates are being sent to Weather Underground, whose pages are rather attractive and have some cool graphs too.


My Cam and Yawcam Too

Something else I had wanted to do for a while was reinstate a webcam feed. For some time my Raspberry Pi had happily processed images from a Logitech C270 webcam as well as running Weewx. Unexpectedly I started seeing problems with both Weewx not running and the webcam images not being uploaded; I have no evidence for this, but I suspect this corresponded to changes in Raspbian to accommodate the Raspberry Pi camera. My Pi is an early (not the earliest) Model B, only has 256Mb of memory and possibly struggled with the demands expected of it.

A Windows OS meant I was able to use Yawcam again. This is a neat, unassuming and free program that will take a feed from a webcam and send images, either still or streaming. I use it to grab an image every 10 minutes and squirt it to my web server where it forms part of the weather webpages on my site and Weather Underground.

iPodge - The Nomad Jukebox 3

Clearing out some cruft from a drawer the other day I came across a Creative Nomad Jukebox 3. This was not a surprise; I knew I had one; I used it daily on my commute by train to London and it helped pass the hours during the disruption of the West Coast Mainline upgrade works.


'A week is a long time in politics', as Harold Wilson may have said and a year is an age in consumer technology development. Before the iPod became the generic term for a portable music player Creative, who were a big player in the computer sound market with their SoundBlaster cards, also sold a range of Windows compatible mp3 players. The Jukebox 3 was introduced in 2002, about the time the 2nd generation iPod made its debut, so Creative no longer had the PC market to itself.

Creative Nomad Jukebox 3 - Won no beauty prizes

At 23mm x 130mm x 35mm and 289 grammes (without batteries) pocketable it was not; the case that was bundled with it (in European markets) had a belt clip on the back, but attaching it to your belt could result in your trousers being dragged down to your ankles. In contrast the iPad was sleek, small and oozed chic.

The Jukebox 3 did have a number of features that made it stand out, notably a 30Gb hard drive (other sizes were available); two line out sockets (in addition to a headphone socket) allowing up to four speakers to be connected and, most importantly as far as I was concerned, an optical / line in socket. This last feature enabled me to record digitally some of my collection of vinyl albums so I could listen to them on the Jukebox. I think Creative had one eye on the (semi) professional recording market as the Jukebox was a convenient way to make recordings and then edit them in a digital format, with all the benefits that provided. Certainly I used an editing program to remove some of the worst clicks and pops from my vinyl recordings.

Later, Creative sold a remote control that contained a microphone to promote the use of the recording functionality. This attached to a proprietary connecter and the headphone socket and also featured an FM radio.

Jukebox 3 Remote - Including mic and FM radio

Transferring files to and from the Jukebox was achieved using Creative's PlayCenter and File Manager software and either the USB or Firewire sockets. The USB socket was only v1.1 and sloooow; the Firewire socket was really fast but I suffered from connection problems, a common issue apparently. Creative's software was clunky and I started using a product called Notmad (now long gone) that was browser based and provided a music streaming function.

When I moved from Windows XP to Windows 7 these problems vanished: the Jukebox's drivers simply wouldn't work at all with 64 bit Windows 7 and so rendered it completely useless. By then my head had been turned by new shiny-shiny and I was in a relationship with an Archos 605, so this wasn't a setback.


The Nomad Returns

Having rediscovered this gem I wondered if would now be possible to get it to work again. Luckily the PSU had been nestled beside the Jukebox in the drawer so I plugged it in, pressed the on button and, after clicking and whirring from the hard drive, was pleased to see it boot up and display the main menu.

That was the easy bit. Making the Jukebox talk to the Windows 7 PC had proved insurmountable in the past and I wasn't too confident it would work now. However, after some Googling I had found references to some users who had achieved this, so I thought I'd have a go.

The key seemed to be to use updated MediaSource progam, plugin and driver software that were available in the support section of the Creative website. I downloaded the Creative MediaSource Player/Organizer 5.10.38 and Creative ZEN and NOMAD Jukebox Plugin 5.00.22 for Creative MediaSource 5 Player/Organizer (phew) files, but found I already had a copy of the Creative ZEN and Jukebox Driver 2.01.00 file so ignored it.

Figuring I would need the drivers I installed them first, followed by the MediaSource Player/Organizer, then hit a problem: MediaSource wouldn't install without the Jukebox being attached. I plugged in the Jukebox and Windows started its process to install drivers then complained it couldn't find the drivers. Frustratingly Windows knew there was a Jukebox attached, it just didn't want to talk to it.

Wondering if the driver had been changed, even though the version number of the driver I used was identical to that on the website, I downloaded a new copy. As soon as I plugged in the Jukebox its display changed to show it was connected and Windows completed the driver install process. Retrying MediaSource this now detected the Jukebox and installed itself, leaving just the plugin which also installed without a hitch.

After rebooting the PC to complete the install I noticed a short white line at the top of the screen. When I moved the mouse pointer over it a small MediaSource panel dropped down.

White line becomes drop down panel

This provides access to the Creative website and MediaSource programs: Audio Converter and Player. Clicking on the Player button opens an application with the standard display and control buttons.

Player 1 to start

The only way to transfer files to and from the Jukebox is via MediaSource Organizer and to access this requires a click on the icon on the bottom left of the Player.

MediaSource Organizer. Lots going on here, isn't there?

The Organizer software dates from the early / mid 2000's and shows it - never mind the quality, feel the width. The somewhat busy(!) interface was initially bewildering but with a few experimental clicks I was able to copy some files to and from the Jukebox.


Jukebox Jive

After this success, what now for the Jukebox 3? Well, nearly all of my vinyl collection has now been digitised, mostly by the aforementioned Archos 605 with post processing done in Sony Sound Forge Audio Studio, so I'll not be needing it for that. My mobile listening is catered for by an excellent Fiio X5, using FLAC files that the Jukebox can't handle. However, perhaps its main shortcoming is its inability to act as a USB mass storage device, which prevents it from being connected to other audio and video devices' USB ports and simply being a music file repository.

Back in the drawer, then. I'm certain it will come in useful one day...

Points on a Curve

At the time of my last post I still had a problem with the daily weather graphs that weewx was creating. They were a series of dots, rather than a continuous line like the graphs for weekly, monthly and yearly data.

One of the beauties of weewx is its tweakability (technical term) and my first thought was I may have bolloxed up (there's another) a setting in the skin.conf file that sets how graph data is presented. Display type is set to line at a high level and you can change this for each graph if you choose; checking this showed it was set to the default. Eventually, by chance, I saw a post on the weewx User Group that explained the reason for this was too large a gap between the data updates. When I configured the Vantage Vue console I had set the archive interval to 30 minutes and this was too wide a gap to cause a line to be drawn.

Weewx offers a tool to find the current settings on the console (wee_config_vantage --info) and then to change them individually: --set-interval=SECONDS was the one I needed, where 'Seconds' was to be 600, i.e. every 10 minutes. Could I get it to work, could I buggery. Syslog told me that it couldn't talk to the console (between providing updates, proving that it could). Eventually I resorted to plugging the console into the PC, firing up Weatherlink and doing it that way. Success! The graphs starting showing a solid line, rather than individual dots.


Port Is Dead

All was well for a couple of days when I noticed at 6:30 (up early to catch a train) that the website hadn't updated since midnight. Puzzled, I logged onto the Pi that evening expecting to find that a power cut had changed the IP address of the NAS but found the Vantage Vue console had been reallocated port dex/tty/usb1, instead of /usb0. Not finding the console on the port in the weewx.conf file Weewx had sulked. I changed amended weewx.conf to look at usb1 and all was well for a while. Then everything failed again.

When I checked the syslog it seemed that the webcam was causing a problem with the USB hub and it was endlessly trying to register with the OS. Resolution? I've unplugged the bloody thing until I've time to work out why it's decided to fail after working perfectly for months.

As an aside, one of Weewx's tasks is to send data to Weather Underground. Somewhat scarily the day that Weewx had gone down I had an (automated) email from them to say that they hadn't received any data for over two hours. Once I had Weewx back up that evening I had another email to say they had started to see data again.

Weather Station on a Stick

Shortly after I wrote the last post the Davis Weather Vue weather station I had ordered was delivered. Inside the box was the console (a small unit with an LCD display and some buttons) and what Davis calls the Integrated Sensor Suite, or ISS (a single white and black plastic unit housing rain gauge, anemometer, wind vane and thermometer). There was also a plastic bag that contained a mounting kit, battery and a teeny tiny Allen wrench so small I thought it was something you could use to poke into the Reset holes present on some consumer electronic equipment.

Along with the Weather Vue I had ordered a USB Data Logger, which was supplied with Davis' WeatherLink software. This is an extra - the Weather Vue will function happily without it - but I wanted to export the data to my Raspberry Pi and a Data Logger was required to do this. Prodata had thoughtfully attached detailed instructions regarding installation and preparation of the software. Presumably they had had plenty of questions from users about it in the past. Depressing, though, that the software and Data Logger hardware hadn't had the difficulties designed out.

Assembling the ISS was trivial. The instruction booklet was well presented and clearly explained how to insert the rain tipping spoon (their word), attach the wind cups and wind vane. The ISS has to be mounted on a pole, so I bought an aerial mast which, at 3cms was about the recommended diameter. Prior to mounting it I tested that it was communicating with the console and then attached it to the mast and the whole lot to the bracket that had formerly held the WH-1080. A nice touch was the spirit level built into the top of the ISS to help ensure it is level.

Ugly, though, isn't it?

Consolation Surprise

The hard part done I turned to the console. To my chagrin I realised that although it had been supplied with a mains adapter it also required three 'C' size batteries. These weren't available in either of the shops in the village and so I had to trek into the nearby town. Once procured and inserted I switched on the console which was meant to run through a self test and beep four times. I lost count after about the twelfth beep and was becoming somewhat concerned at the random messages on the screen and constant reboots.

Eventually the console settled down and I was able to start the setup process which, apart from finding elevation, latitude and longitude (Google Earth is your friend here), was pretty much a case of accepting the defaults. Once complete the latest data from the ISS is displayed together with astronomical events - I was pretty impressed to see it show that the Taurid meteor shower was due.

All this, and more

By pressing one of the buttons on the console it's possible to obtain more information about, say, the wind as well as displaying the data in the graph in the bottom left of the display. At present I've only scratched the surface of the information it is possible to display.


Web Weaver

The next stage was to link the Vantage Vue to my Raspberry Pi and upload the data to a web site. Firstly I installed the WeatherLink software that had been supplied with the data logger onto my PC which enabled me to test that I was able to download data from the console. This worked without a problem so I installed the latest version of the excellent Cumulus software, again I was able to receive data with no errors.

Being unfamiliar with weewx (and somewhat shaky with Linux) knowing that the hardware worked meant one fewer place to look if it didn't work. The beauty of weewx is that it's pretty easy to set up, offering two ways to install itself (via a package or from a downloaded tar file); both methods are explained in the docs section of the weewx website. I opted for the tar file method as it installs all the files in /home/weewx and it seemed easier to have all the gubbins in the same place.

After weewx was installed I had to edit the weewx.conf file to set the altitude, location and weather station type. This step is well documented in the docs and I used Leafpad on the Pi via an Xming session to make the changes. Yes, yes, real men use the command line, but I don't care. An extract from the weewx.conf file is shown below.

Easy peasy configuration file editing

The part that had me scratching my head was the FTP sections - crucial to get right if I wanted to see the data on the web. For the server name I first used the local URL of my web server (actually a Qnap NAS) and this failed. Eventually I had success by using the IP address of the NAS.

After I had finished fiddling about I started weewx and watched the log with crossed digits. Everything looked good, especially the FTP upload, so I opened up the webpage and was rewarded by data from the weather station and a selection of graphs. As my confidence editing weewx's index.html.tmpl file grew I added a feed from the webcam and satellite information from Meteox. This is the final result or you can peruse the half-hourly feed to Weather Underground and The Met Office Weather Observation Website (WOW).

So everything's sweetness and light. Well, not quite. I have an issue with the daily graphs in that they plot points and not lines; oddly the graphs for monthly data correctly show lines, dunno why the daily graphs don't. Before I ask on the weewx forum I want to eliminate the obvious.

Beeching Axe

I had been finding it increasingly difficult to make compromises with what I wanted to do with the railway layout and the space available. Ideally I wanted to be able to set up a train consist (as our North American friends call it), set it going around the layout and then I could do some interesting shunting stuff in the station yard. This concept had worked on a layout I had built some years ago, but then I'd had much more room.

Raised track at the rear of the layout (see posts passim) was created to provide some scenic interest; the idea was to create an illusion of mainline running tracks separated from the station area by the difference in height. However the inclines were starting to cause difficulties with train running and it was clear that it would cause difficulties scenically too. Ironically it was lack of space that was the reason for the failure of this idea.

Unsatisfactory. That was my view as I tried to fit the quart of ambition into the pint glass of baseboard. In the end I decided to dismantle the whole lot, baseboards included, and have a fundamental rethink. Whatever I decide to do, it will have to be built in the attic as there's no room in the house for what I want to do. Before that happens some kind of flooring and insulation will need to be installed to prevent my frostbitten (or, depending on the season, roasting) foot coming through the ceiling.


Weather Report

Nearly a year ago I wrote about using a Raspberry Pi to upload weather data from a Fine Offset WH-1080 weather station to a website. For the most part the WH-1080 has worked well and has been a worthwhile introduction to weather data collection. At the time of writing the WH-1080 is being sold in the UK by Maplin for a whisker under £60 (product code N96GY).

There have been some hiccups with interruptions in data transmission from the outside unit. Prompted by an outage lasting over a day I bought a replacement transmitter, only for the original unit to start working again. It's still prone to occasional dropouts, seemingly without any correlation to weather conditions or invertebrate infestation. The latter stopped the anemometer until I was able to clear the spider webs.

Weather Station and Spider Habitat

Presently, however, the unit isn't recording wind speed or direction data. The receiver unit shows changing wind direction but not the wind speed, and neither are being uploaded to the website. This isn't just an issue with pywws, the Cumulus weather software isn't receiving the data either. Dismantling the anemometer showed nothing apparently wrong with it; not surprisingly as all that's inside is a reed switch and a tiny magnet. As repair wasn't possible I ordered a new unit from Maplin. And I'm still waiting for it. The buggers have taken my money (£5 with postage!) and it's still 'on order'.

Finally I decided to order a Davis Vantage Vue weather station and data logger from Prodata, who are selling them together at a 'special offer' price. The Vantage Vue consists of a combined sensor unit containing rain bucket, anemometer, wind direction, temperature and humidity sensors. Like the WH-1080 the sensor data is transmitted wirelessly to an internal console with an LCD display. An optional USB data logger is required to store data and send it to a PC. My plan is to use weewx, a linux-based weather software application, installed on the trusty Raspberry Pi in place of pywws (this program won't work with the Davis unit).

Presently I'm waiting for the thing to be delivered (every noise outside sends me to the window to see if the courier has arrived) and when it is, I'll document how I set up both it and weewx more carefully than I did for pywws and the WH-1080. I'll spare you the unboxing, though.

Soldering On

Up until now I've been testing the locos on the layout with a couple of pieces of speaker wire, attached at one end to my venerable H & M controller and held onto the rails at the other with my fingers. Apart from the dexterity required to stop the two pieces of wire touching, I also had to dodge speeding locos. Time to Do It Properly.

Express Models sell DCC kits comprising of wire with a gauge suitable for the power bus; thinner gauge to link from the bus to the rails; crimps and spade connectors. The kits contain more than I needed so I picked the bits I wanted separately and sent an order. A few days ago it arrived and I spent a wet Saturday wiring up the layout.

Goody bags

Accepted practice wiring for DCC train operation is to run a power bus - basically two cables with a reasonably meaty cross section, one for positive, the other negative - underneath the baseboard. To this are attached a number of thinner wires, the other ends of which are soldered to the track. I decided to run my power bus as a loop, the ends joined to a terminal block. It doesn't have to be a loop; a long length of cable running to each end of the baseboard will work too. My power bus wires are held up by threading them through plastic loops originally bought for home cinema wiring (I knew they'd come in handy one day).

I drilled through the baseboard next to the track for the dropper wires in several places, chosen to eliminate dead spots no matter how the points are set. Prior to soldering the dropper wires to the track I used a small rat-tail file to clean the side of the rails at the point they were to be soldered. This cleaned off the crud and helped ensure a better joint. Some solder was then applied to the sides of the rails; the ends of the dropper wires were tinned and then soldered to the rails.

Once I had soldered the dropper wires I realised, from the cramped and awkward space that exists under the baseboard, that the spade connectors wouldn't crimp onto the wires but needed to be soldered too. I'd have to hold the wire with one hand, the connector with the other and manipulate the soldering iron with my third. Bugger. Eventually I figured by tinning the connector and holding it against the wire with a pair of pliers I could heat them both with the soldering iron and obtain a good joint. The crimps were then fastened to the bus wires by squeezing them closed with a pair of pliers and the spade connectors were then attached to the crimps.

Knit one, purl one

All that remained to do was link a couple of wires from the bus to the H & M controller and turn the knob. I was rewarded by the shunter moving smoothly along the track much better than before, solely due to having more power feeds which reduced the power losses through the track joints.

There was only one glitch which was caused by the electrofrog point, or rather how I had installed it. To stop short circuits you need to use insulated rail joints, which I'd done. What I hadn't done was to put them on the correct rails, so as soon as I switched the point to another route it created a short circuit. I moved the errant joiner so that both insulated joiners were adjacent to one another on the rails coming from the frog and the problem was solved.

As cabled the layout works OK if there's only one DC loco on the layout. All tracks are live so if another loco was placed anywhere else on the layout it would also move, and in the same direction. The next step is to purchase a DCC controller and loco, which I plan to do at the forthcoming International N Gauge Show.