Cumulus, USB, and 1-wire

[yv1hx]

Steve, The "Fine Offset" stations have a Data Logger ?

Yes, they do. As does Charlie's device.

Thanks Steve!

[Charlie]

Just an update - the first production unit has been running without issues for about 8 weeks now. A second unit has been installed (on the opposite side of the planet) and seems to be happily reporting data as well. I have a small quantity of finished units ready to go, including documentation (about 20 pages), and some diagnostic tools that can be helpful during setup.

Despite the tools and documents, this is a station for a technical user who wants to experiment a bit. Not that it's overly difficult, but I’m not sure I’d ask my wife to install it as it’s not quite as “plug and play” as the F.O. it’s replacing. There are advantages, though. It is nice to be able to test out various types of humidity sensors, for example, and it supports a few different types of popular sensor models that use different protocols.

The indoor unit that connects to Cumulus by USB provides indoor temperature, indoor humidity, and barometric pressure, and of course the data logger. The external sensors (1-wire) include temperature, humidity, wind direction and speed (ave & gust), rainfall, lux/solar radiation, and UV index. Everything connects with standard ethernet cables, although I plan to swap mine for direct burial CAT-5 eventually. I did need to customize some of the commercial sensors slightly, so I could eliminate the human intervention inherent with 1-wire gear. (instructions are in the manual) Things like assignment of sensor unique codes to applications is done without entering any data.

I've done a few things to make sensors more accurate than usual, including compensating for local temperature and system operating voltages where those parameters could impact the result of the measurement, and elimination of 1-wire parasitic mode which is not necessary since all the sensors have local power supplied over the ethernet cables anyway, and parasitic mode just introduces small amounts of error and noise. Communication links are all CRC protected, and there is some software based filtering of measurements where it makes sense to do so.

I’ve been asked about extra sensors – The short answer is that the station has no display of it’s own, and uses Cumulus exclusively, so it does not support any functionality that Cumulus does not support. Since the unit emulates a Fine Offset with UV & Solar, it does not provide any sensors beyond what that unit provides – just better quality, accuracy, and hopefully longevity.

[Gina]

Very interesting Charlie I have built a 1-wire weather station as you know but it doesn't go as far as yours and it uses my own software. However, Steve has developed Cumulus way beyond anything I've done and to interface to Cumulus seems a very good idea Kudos to you for getting your system working and combating the problems of USB. When I was younger I might have been able to do something similar myself.

I have to admit that although many years ago I was a fair whiz at software and interface development (as a part of my profession) my abilities have deteriorated with age and I find I can no longer get my head round complicated software any more It is unfortunately the case that I'm finding I have to lower my expectations of what I can achieve both physically and mentally. And everything takes a lot longer than it used to. I'll be 70 in a couple of weeks so I guess it's only to be expected. Have to say I don't feel old but do find I can't do what I used to.

I plan to get back to weather station development but don't expect any fast progress.

[Charlie]

Congratulations on your milestone, Gina! The beauty of retirement is that you don’t have anyone demanding things be done yesterday, so you can work at your own pace. None of us are as speedy as we were 20 or 30 years ago, but at least we’re still moving!

Since my station emulates a Fine Offset it should work with G-weather too. I noticed in your other thread that you have all the 1-wire sensors in place, and you have G-weather working with a Fine Offset, but you still need to write a translation block to make 1-wire sensors work with G-weather. Perhaps a hardware translator like mine might be the way to go. In fact, using mine could free you to work on other areas of the system. I’d be happy to go through each of the sensor designs with you, and I’m happy to make changes where necessary, but from what you’ve posted, I suspect everything should work right out of the box. I am emulating a 3080 rather than a 1080, however, so you might have to modify G-weather to deal with solar data. Or perhaps you already have – I have not been to your site for awhile.

In any case, you’ve been away from this board too long and it’s great to see you back! We’ve missed you. You’ve helped many of us understand these stations better, and you actually started me down this development path a couple years ago with Fine Offset discussions (and dissections).

[Gina]

Thank you for your kind words Charlie

Yes I agree your station should work with G-Weather. I also think that my 1-wire station should be quite easily interfaced with G-Weather as both use Python as the programming language so I expect to have solar info added to G-Weather. The whole thing is modular so adding extra bits is relatively easy. But your hardware solution seems a great way to interface with Cumulus. Without the source code for Cumulus, interfacing my 1-wire station to Cumulus is not trivial. I shall be interested to see what price you decide to charge for your translator.

[Gina]

Got my old laptop working with my WH1081 and G-Weather at last Had to sort out some LAN problems - my network switch seems to have stopped working so I've got the laptop plugged straight into the router. So I'm limited as to how many computers etc. I can connect to the network.

Next I want to get the 1-wire setup working again. Astrophotography has had to go on the back burner for a while due to the dreadful weather so I'm working on my weather stations. I need to replace some outdoor cables which have been chewed through by rats! Fortunately I have plenty of CAT5E cable.

Still a problem I see - the weather is not updating in my sig Strange, the website appears to be working as usual and I haven't touched it since it was all working before. Something else to fault-find!

[Charlie]

Hi Gina - sorry a reply took so long; We've been off on holiday for a week or so.

I've added up the hardware costs for the translator alone which includes sensors for indoor temp, indoor humidity, and barometric pressure, and I think it should sell for 95 GBP including various taxes. For others reading this thread, I should point out that even though we are referring to the device as a translator, this is actually a complete weather station (less outdoor sensors and display) using 2 microcontrollers and about 50 KB of custom code.

[Gina]

Thanks for your reply Charlie As you may have seen from another thread, I am going ahead with my 1-wire plus Arduino weather station. I may make this emulate the Fine Offset later on and in fact, am bearing this in mind from the start.