Buillding Myself an ORx (Outernet Receiver)

Othernet Hardware Outernet Receiver (ORx)
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I thought it would be interesting to build myself an ORx (Outernet Receiver) so that I can play around with it and get a real feel for how easy (or difficult!) the whole process is.

I am going to document the build, and I plan to use this thread as a diary to record the various steps as I go along, and to report my successes (or failures) in trying to get it all to work. I’m going to take pictures and videos of the various steps as I go along, and link to those here too.

I hope that this will be a useful and interesting read for others planning to build their own receivers in order to test out the Outernet service. Do feel free to comment and ask questions at any time.

It would also be interesting to hear tips and advice from others who are building, or who have built, their own receivers.

For anyone else planning to try it too, here are the instructions on what you need to do.

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Step 1: Obtaining the Hardware - 18 August 2014

The first step in the process was to get hold of the necessary hardware, since I didn’t have any of the components already to hand.

The instructions were clear and easy to understand, and I thought that the best place to head for was eBay (in my case it’s eBay UK).

  1. Antenna and LNB

Getting a Ku-Band antenna (dish) and LNB was very straightforward, although there was a lot of choice available. In the end I decided to go for a portable/camping kit, as this would give me the flexibility to set up the kit and then move it from place to place (I’m already thinking that that could be an interesting technology demonstration for schools - I’m also a schools’ STEM Ambassador). This is the antenna/LNB kit that I have chosen:

Details are here. The antenna, LNB, tripod mount and satellite-finder (aid to pointing the dish correctly) cost UK£ 45.99 (US$ 77.00).

  1. DVB-S2 Receiver

The instructions listed three possible options for the satellite TV receiver, but I could only manage to find the first one on eBay. So, by default I have purchased the PCTV 461e:

Details are here. This was the most expensive purchase and cost UK£ 83.80 (US$ 140.00).

  1. Raspberry Pi

Again there were lots of options on eBay, but I settled on a Raspberry Pi B+ kit, which came with everything that I needed, including power supply, SD card, pre-installed operating system, WiFi dongle etc.:

Details are here. This kit cost UK£ 51.50 (US$ 86.00).

  1. Other bits and pieces

I bought 20m of satellite cable, to connect the LNB to the receiver, and a mini keyboard and mouse for the Pi. I already had an old VGA monitor, so I bought an HDMI to VGA adaptor, so that I could connect the Pi to the monitor

So, that’s everything. Total cost was UK£ 216.13 (US$ 362.00). It’s not cheap, but I guess that if I had more time (I quickly purchased it all during my lunch-break! ) I could have got things cheaper. I’ve bought everything new, for example, and used kit would have been bound to be cheaper. However, I wanted to give everything the best possible shot of working “out-of-the-box” so thought that “new” was the best option. At this price the receiver is likely to be too expensive for many, but I am sure that $360-odd is not going to be the final price as ORx gets packaged into a consumer item. For me it’s all reusable anyway, so I decided to go for it.

Now all I have to do is to sit back and wait for it all to arrive!

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Since you went for PCTV 461e, you will also need to Install Arch Linux ARM on Raspberry Pi. You will also need to update the kernel to latest version as per my instructions because PCTV 461e will only work stably on Linux 3.16 (latest and greatest on Arch ARM as of this writing).

It’s not mentioned in the instructions, but, if you’re new to Arch Linux, you may want to make sure you’re using the fastest mirrors.

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Many thanks! I tried to find a 460e or one of the other receivers, but all I could locate on eBay UK was the PCTV 461e.

Actually, since I’m a satellite engineer, and not a computer engineer, getting the software side running is the bit that I think I’m going to find most difficult (that said, back in 1987 - 1989 I was sysadmin on an HP 9000 Unix machine in British Telecom International’s HQ, so I’m hoping that Linux will not prove to be too daunting!).

I’m sure that I’ll be back for help, if I get stuck! I’m really looking forward to setting this up. Been about 25 years since I played around with radio hardware in any serious way!

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Any pain you go through will contribute to the easier install for the next person. :smile:

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I am very excited about seeing this come about. Once you have an operational system in place, it would be great if you could experiment with smaller and homemade dishes to see how the signal is received as gain is reduced.

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Hi @Syed, glad you are excited. I’m excited to be building it! It’s probably going to be next week before all the components have arrived and I can try to get it up-and-running, but I’ll be sure to record everything here as I go along.

Regarding experimenting with smaller and home-made dishes, I can certainly try to do that, but in any case, once it’s all up and running I will depoint the antenna away from the satellite and normal to the line of the GSO, and see how far off-axis I can depoint and still get a working signal. From that I can work backwards to calculate the minimum gain towards the satellite at which the signal can still be received and demodulated. This will give you a rough idea as to the smallest size antenna that can receive the signal, although it won’t allow for the increase in adjacent-satellite interference that would also arise from a smaller reflector.

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Apologies for still not having set up that Skype call, but while we’re both here: Do you have any thoughts on how to solve for interference issue with satellites being spaced only two-degrees apart? I think the real key for widespread adoption is:

  1. Completely integrating the system into a portable satellite hotspot
  2. Significantly reducing the size

Petalization of the antenna is one way–kind of how it’s done in the video, but I’m wondering if you seen that problem solved in other ways.

I’m not going to be happy until a fully-integrated, completed automated, carry-on sized hotspot costs less than $50.

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I just realized that I’ve been learning from your satcom experience for a couple years now–on Quora!
Regarding the adjacent satellite interference: Are you aware of any specialized (and low-cost) antennae that are low-gain (and consequently smaller in aperture), but still limit their field of view to 2-degrees? I’m sure that the laws of physics are not on our side, but maybe there is something we are overlooking?

When we eventually move to a single carrier, versus being on a multiplexer like we are right now, I was told by the operators that we could always increase the power going into our channel. In theory, this would allow for less gain on the ground. But like you mentioned, with less gain there is greater interference.

Is there an equivalent to blinders for satellite dishes?

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Step 2: Setting up the Raspberry Pi - 22 August 2014

A few days after ordering the various components from eBay, boxes started to arrive. I now have everything except for the DVB-S2 satellite receiver (which is coming to the UK from Italy and may take another week!).

So I thought that I’d start by seeing if I could get the Raspberry Pi and the Outernet software up and running first!

I first put the Pi hardware together plugging in ethernet, a monitor and keyboard:

Getting the Pi itself to run was very easy. The Pi that I ordered came with an SD card pre-installed with a helpful “set up” package called NOOBS, which did all the hard work. Because I have ordered the PCTV 461e receiver, on the advice of @Branko I used NOOBS to install the Arch Linux OS.

Once Arch Linux was installed I rebooted the Pi, and that was where the fun started! Although I am old enough that my computing experience dates back to pre-history (I used to program a 6502 microprocessor using hand-assembled machine code!) it’s been a long time since I used any computer that didn’t have a pretty graphical interface. Arch Linux, on the other hand, looks like this after it is booted:

However, @Branko’s instructions came to the rescue and I was able successfully to update the Linux kernel, and then download and install the DVB Headend software and the Outernet package itself.

Although the instructions look a bit daunting, it’s really just a matter of typing the correct commands and then waiting for everything to finish.

After that was done, I rebooted the Pi and, with some trepidation, I connected to the Pi’s IP address on my network from a browser on my Windows PC. First I conected to port 9981 (again as per the instructions provided by Outernet), and lo and behold the TV headend software was running:

Then I connected to the Pi’s IP address without specifying a port number (once again, see the instructions), and I was very pleased to see that the Outernet Librarian software was also running:

Of course, since the satellite dish and receiver are not yet connected, there is no Outernet content being downloaded:

However, it all seems to be working and (hopefully!) once the receiver and dish are connected up then I should be able to start receiving content.

I am now anxiously awaiting the DVB-S2 receiver so that I can go onto the next steps. Watch this space for updates!

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Nice job sir,
And wish you all the best!

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Step 4: Setting up the DVB-S2 Receiver - 28/29 August 2014

Well, it took a week to arrive from Italy, but my PCTV 461e DVB-S2 receiver was finally delivered this week, and on Thursday I finally found some time to set it up.

In principle it should have been quite straightforward. All I needed to do was to connect the receiver to one of the Raspberry Pi’s USB ports, plug in the power supply, and reboot the Pi, so that the software installed by the Outernet package would recognise the receiver.

I did all that, and then connected to the TV Headend (as I explained above) and then tried to connect the Headend software to the receiver through the settings menu. But… nothing! The software didn’t see the receiver.

I disconnected everything, reconnected it, rebooted the Pi… still nothing.

Fortunately @branko was able to help by telling me the command to run on the Pi to see what was happening as the software tried to set up the USB port:

$ dmesg | tail
[ 1264.730419] usb 1-1.3: Product: PCTV 461
[ 1264.740483] usb 1-1.3: Manufacturer: PCTV
[ 1264.750671] usb 1-1.3: SerialNumber: 0011421164
[ 1264.767132] em28xx: New device PCTV PCTV 461 @ 480 Mbps (2013:0258, interface 0, class 0)
[ 1264.793846] em28xx: DVB interface 0 found: isoc
[ 1264.804196] em28xx: chip ID is em28178
[ 1264.976707] em28178 #0: em28xx_init_dev: em28xx_write_reg failed! retval [-5]
[ 1264.992262] em28xx: probe of 1-1.3:1.0 failed with error -5
[ 1265.004141] usb 1-1.3: USB disconnect, device number 61
[ 1265.176710] usb 1-1-port2: over-current change

That message, plus a bit of help on the Outernet project’s Github page, led us to conclude that the Pi’s USB ports were not able to deliver enough current to the receiver, and so it was not working properly. (Note that I have a Raspberry Pi B+ which has 4 USB ports rather than 2, and possibly this may have been the cause of the problem.)

So, off to the internet to order a powered USB hub!

This arrived on Friday. I connected it up, plugging the hub into the Pi and the receiver into the hub. I rebooted the Pi and was pleased to see that the Pi now recognised the receiver, and the receiver showed up in the TV Headend software. Another problem solved!

I still don’t have the satellite dish connected to the receiver, so no data is arriving yet, but I am almost there.

I had hoped to set up the dish on Friday too, but I was too busy and ran out of time. Next week I’m travelling on business, so the final step to getting my ORx up and running is going to have to wait for another week, unfortunately.

Watch this space!

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16 October 2014: (Lack of!) Progress Update

This is just a brief update to everyone who is wondering what has happened to my ORx construction project.

Unfortunately the last 6 weeks have been crazily busy at work, and I simply have not had the time to do the final step, i.e. setting up the Ku-Band satellite receiving antenna and connecting it to the receiver.

I’m hoping to have a bit of time next week to get it done! If you are following this then I’m sorry to have kept you waiting.

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If you haven’t seen this, Librarian has a new version release:

https://discuss.outernet.is/t/librarian-0-1b1-first-beta-release/786

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"led us to conclude that the Pi’s USB ports were not able to deliver enough current to the receiver, and so it was not working properly."

This is typical issue with the Raspberry Pi. Most sellers bundle cheap 5V @ 1A power supplies or bad quality 2A versions that don’t seem to deliver the right power.

Can you confirm the Amp rating on the wall wart you have? Because big picture, there is a price increase to go to 2A power supplies and someone needs to test this setup with such to see if that will indeed cover the Pi + wifi + tuner.

Your build cost was quite high.

At $350-400 one can get a full FTA setup with motorization and add on other tuners to interface with the Pi (likely far less costly).

Obviously, the Pi is a chunk of that cost and aside from wide availability, other ARM platforms should really be considered. The model B Pi’s are $45~ base. Getting that down to something like $25 should be a goal especially long term when these go into production. I recommend someone talk to Marvell as they have a bunch of options and have since 2009~. Bound to be seated upon perfectly good and cheap inventory unused.

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I’ve tested B+ with a 5V @ 1A charger for my HTC phone, and it works correctly (with tuner + wifi).

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@elroot Which Marvell single board compute are you referring to? One that is $25? One really low cost option, that is slightly more open and just as well documented, is the TI AM335. There is also the AM1808 which is much lower power (pros and cons there, especially for Lantern). But for $25, the only complete system on a module or SBC that I am aware of is the Raspberry Pi A+.