19 June 2017

The integrated Maxi

Briefly recapping, the Flex controller project has two principal components: the I/O controller and the Host controller. The I/O controller is effectively a firmware system that is logically part of the physical hardware. The host controller is any Windows-based system that does all the heavy lifting work of the controller application.

For the Mini controller, it makes sense that the host controller might be something like a laptop, thereby creating a portable package for remote use in hotels and the like. It seems to me that the Maxi controller is more of a base station beast and that is the logic behind the concept of The Integrated Maxi.

A typical FlexRadio-based station (mine, as it happens) has the following amateur radio software applications:
  • Logging program
  • Mapping application (e.g. DXAtlas)
  • Propagation application (e.g. IonoProbe)
  • Smart SDR
  • Maxi Controller application
...and so on. With the exception of Smart SDR, none of these programs are particularly demanding in terms of processor power or memory. It therefore seems reasonable to run all these applications on a single Windows system. And if we are doing that then why not integrate it with the Maxi controller?

The problem is finding a suitable Windows platform. Required attributes are as follows:
  • Sufficient processing power and memory to handle all required applications
  • Support for up to three screen: one for Smart SDR, one for the logging and support applications and one for the controller display
  • Low power consumption
  • Good connectivity (network, USB)
  • Small physical size
That's quite a shopping list. I've started experimenting with the UDOO X86 Ultra, which appears on the face of it to meet all the above requirements. With 8GB of RAM, memory isn't going to be a problem but processing power might be. Connectivity and the other attributes are satisfactory.

Here are the UDOO X86 Ultra CPU loadings for the above applications:
  • Logging program (StarLog): up to 3%
  • Mapping application (DXAtlas): <1%
  • Propagation application (IonoProbe): <1%
  • Smart SDR: Typically 27% *
  • Maxi Controller application: Up to 4%
* The Smart SDR CPU demand is very much dependent on the application's display settings . The figure given is at 20 frames/sec and 70% average, which are values that I seem to like. A reduction in FPS has a corresponding reduction in CPU load and is not really visually noticeable until FPS<14.

With all applications running, total CPU load is around 36% which gives good headroom for peaks. Here's a picture of my test lash-up:


I'm using a SATA III SSD, which has more performance than I'm ever likely to need but rotating discs are so last year and SSDs are getting cheaper all the time. I happened to have an unused copy of Windows 10 Professional lurking in the shack so despite my misgivings about the W10 platform, I have decided to use it here. Needless to say I have turned of every bit of snoopware that I can, disabled Cortana and so on!

Power consumption at average load of 33% is around 0.9A at 12V, which is very satisfactory, given that the PC is likely to be on 24x365. At 33% CPU load the CPU heatsink is not quite sufficient on its own, so a small temperature controlled fan has been added, which only runs about 25% of the time.

So far so good. Testing continues...

16 June 2017

Belated update

I've been rather remiss in updating this Blog over the past couple of months, although the truth is that not much has been happening on the FlexRadio Controller front.

The USA trip went well and it seems that my presentation at Visalia CA was well received. The visit to FlexRadio in Austin TX was somewhat abbreviated due to staff availability and not helped by a configuration c***up on my part which meant that I was unable to demonstrate the controllers properly. It wasn't until I got back to the UK that I realised what I'd done wrong!

Now safely back in Cumbria, I've been gaining some hands-on experience using the controllers to chase DX and on the whole everything seems to work admirably. A few minor problems have been teased out and the code is moving forward as a result but at nowhere near the pace of a couple of months ago.

My mind is now turning to integration of the host processor into the Maxi Controller cabinet. The key component of this is a Windows Single Board Computer (SBC). I have received and am evaluating the Udoo X86 Ultra SBC for this role. Early indications are promising. The idea, if there is sufficient processing power, is that the SBC will run Smart SDR, the controller host program, logging program and any other ancillary programs needed for DXing. I'll write more about this soon.

9 April 2017

Going international

It was great to see lots of people at the GMDX convention last weekend. My presentation seemed to be well received and generated a good number of in-depth questions. It was the right decision to not do a demonstration as part of the presentation: there wasn't enough time and it would have been too disruptive. Instead I set up a demonstration station in the coffee area and had a large number of interested visitors with often quite technical questions. It is clear that there is a lot of interest in SDR these days.

http://www.dxconvention.comMy mind now turns to the International DX Convention, more commonly known simply as Visalia. I will be giving a broadly similar presentation there on Friday 21st April at 10:30 in Charter Oak, rooms A/B/E. Again there will be no demonstration but the plan is to have my controllers on the FlexRadio booth. If possible I will try to connect one of them up to a Flex radio - I am sure they'll have one or two there!

If you're a delegate at the convention, please do come by and say hi.

31 March 2017

GMDX Convention

I'm starting to pack up everything ready for the GMDX Convention tomorrow. I'll be presenting my paper at 15:30 but there will not be time to attempt any sort of demonstration during the presentation. Instead, I hope to be able to set up a demonstration in the adjacent room, where coffee is served and I will try to man that during break times.

I will have both mini and maxi controllers running but as my laptop is somewhat video ports challenged I'll only be able to display either the mini OR the maxi screen actually on the controller's built in display.

Looking forward to seeing lots of you there.

30 March 2017

PCB update

I now have a few requests for PCBs and am planning to place an order for 10 of each board - mini and maxi - in the next few days. The cost difference per board between 10-off and 25-off quantities is under $1, so there is no real advantage in taking the risk with a larger quantity.

If you think you might want a board or two please do let me know - full details are a few posts below this one.

Update 2017-04-09: The PCB order will not now be placed until I return from Visalia.Too many issues to resolve in the time available and it was always going to be tight on delivery time scale, so it's better to wait until I am back from my travels.

28 March 2017

Mini controller finished

The mini controller is in its box and looks great! This should be a really good form factor for remote operation away from the shack.

Showing VFO-B as the control VFO (note underlined frequency!)
I'll be taking both the Mini and the Maxi controller to the GMDX convention this coming weekend. All I have to do now is finish my presentation...

Maxi controller QRV

Today I completed construction of the Mk II Maxi Controller and put it into service as my main station radio controller. This involved moving the host controller code over to my station PC - the first time the code has been fully separated from its development environment.

The development environment is a considerably more powerful system, so I was interesting to see how the controller would work on a less powerful and, perhaps, more commonplace processor. In fact only one problem emerged - it was necessary to add a few lines of code to ensure that the default  Windows time slice was set correctly so that the many timers in the code would work reliably. This had not been a problem on the development machine but it was soon readily apparent on the station system!

So this is a big step forward today. The Mk I controller has been retired and I am now fully operational with the Mk II hybrid architecture. So far it seems to work just fine, although conditions are poor and there's not much to work.

Big empty box! All the Maxi hardware is on the panel PCB
At least the box can be used as a base for the microHAM
A general view of the 'WGV station