@radhoo, the SD card doesn’t go offline every time that I arrive home and put it in place for an upload of offline data, probably in part because I’m aware of it, but the combination of conditions that I mention is consistent.

I ended up buying a few of each of five different types of GPS antennas, totaling ~AU$75, but I haven’t received any of them yet, due to slow shipping from China; some have arrived in Australia now, though.
Also, you haven’t provided any instructions on how to take the Model D apart, as per one of my previous posts:

In the meantime, could you please provide instructions for disassembly, so that I can have a go at mounting the small antenna inside the model D? In particular, disconnecting and reconnecting the screen; as well identifying any items that are particularly fragile or for which special care must be taken.

I must confess that I was beginning to wonder if @radhoo or anyone else still read this thread and was considering not posting anymore since, with no one else participating, it was essentially turning into my blog – so it’s good to see a bit of activity here 🙂

There is a field of improvement in the recognition of “offline” state.
Whenever the connection to the WiFi router is given, but the data is not possible to be put on the server (on my device it occurs every day or second day – still do not know why), Model D does not recognize it itself as “being offline”. Thus it does not collect data into the buffer for the purpose of putting it through “sync” command later on. Sadly whenever I check the device’s state on the webpage in the morning (it’s a curiosity that the disconnection to the uradmonitor.com page occurs always shortly after 4:00 am), it is shown as “online”. The correct status “offline” is shown after I come from work and check the data again. Here I can see, that no data has been put onto the server since 4:40PM)

I’ve established some consistency with the SD card going offline.

It seems to occur when the following things all happen at once:

• it regains GPS lock (after having previously lost it)
• it connects to wireless (after not being connected)
• the screen is on (possible factor)
• connecting to power (possible factor)

When the first two things are occurring simultaneously, the model D is unresponsive for many seconds (5+), so I think something is happening to make it unmount the card.

The connector was soldered after it was installed.

That’s going to complicate things, then.

Because I had some excellent results with the small antenna, and considering it for the next design update, in order to get rid of the external plastic holder, or at least replace it for something more comapct.

Oh, I see. Perhaps I’ll try both then. Either way, given the amazing shipping times and limited shipping options from China, it will be at least 2-4 weeks until I can try anything. In the meantime, could you please provide instructions for disassembly, so that I can have a go at mounting the small antenna inside the model D? In particular, disconnecting and reconnecting the screen; as well identifying any items that are particularly fragile or for which special care must be taken.

I have somehow managed to reassemble it such that the GPS is working quite well but the cover is loose, so I’m not expecting that to last.

Did it still have power? I didn’t consider that long sync sessions will waste all battery, this is on the list for the new firmware too.

It had been connected to power for nearly 24 hours at that point, as I didn’t go out anywhere on Sunday. I almost always sync offline data when charging now, regardless. When I couldn’t wake it up, the power button also didn’t work, which led me to the belief that it had frozen/locked-up – I had to press the reset button and after that the power button was able to be used to power it up.

Hi Radu,

That reading you are seeing must be from the factory in China because my unit is not connected to WiFi. The problem I just found was that my WiFi key is 4 characters longer than is allowed on the Model D. I’ll have to change my key.

Well, I now do regret taking photos of the GPS antenna – as my model D now has no GPS reception at all. It was initially ok after reassembly but it started to become unreliable, and ultimately had sketchy reception, so I took the cover off and flipped the antenna back to the correct orientation (foil side down) and I don’t think it’s had a satellite lock ever since. Testing with a multimeter, there is a short in the cable; massaging and maneuvering the cable can resolve it but a small move is all it needs to return.

Does the connector fit through the hole or was the cable soldered onto the antenna after it was installed?
I think the antenna cable really needs its own hole and I think that hole also needs a grommet to protect the cable. I believe that reinstallation of the antenna cover, after coming off numerous times, is what has caused this failure; the peg on the cover has simply crushed the cable and also stripped some of the insulation.

@radhoo, I’m wondering why you’ve suggested changing the antenna over to one that has ~15dB of gain, versus the original which, as far as I can establish, probably has 28dB of gain. This page shows a number of different antennas, including what I believe is the same as the standard antenna. I’m considering this 32dB antenna.

At 13:14 today, my model D stopped uploading because it had frozen – which I think is a first for mine. I noticed at ~18:20, when I picked it up to have another go at the GPS antenna cable and couldn’t wake the display.

Hello,

Having only incorrect temperature, humidity and pressure readings from my Model D, I was resigned to using it only for air quality and radiation measurement.

Currently, my area is experiencing the worst air quality ever
recorded (due to thick smnoke from forest fires). Visibility is down to 1 km and particulates are falling on my property but my Model D says air quality is normal.

I guess I will just use it to measure radiation. (After I test it against a known source to see if it actually can do it).

I have just received my model D.
I was trying to set it up when it start buzzing and no way to stop it with a white screen.
Is it a reset button somewhere ?

I’ve attached some photos of the VHB tape that I used as padding. Again, you don’t need to use VHB tape and, in fact, it’s probably an expensive way of doing it, if you don’t already have it lying around – any foam tape about 1mm thick should do.

I’ve also attached some photos of the reoriented GPS antenna and cable. I’m hoping that I’m not going to regret doing this now, because it took ages to finally get a satellite lock after I reassembled it; so hopefully I haven’t made it worse in the process.

@Kurt, by default, the foil side faces the model D chassis. However orientation doesn’t seem to have much effect.

I think I worked out what the issue is/was with the GPS in my model D. Over the last couple of weeks the GPS antenna cover has become somewhat loose and detached many times; as a result of this it looks like now the antenna cable now has a small section of insulation missing and this may have been contacting the chassis of the D. I flipped the antenna over in the antenna cover, which routes the cable in a slightly different direction and I now receive 9-11 satellites in my car and 5-9 satellites where I charge it – at both of these locations it received zero satellites before I made this discovery.

I was planning to flip the antenna over, when I discovered this issue, because I found that, whilst reception was terrible standing up, it would actually receive a GPS lock when laying on its front – which made little sense. After having rerouted the cable, orientation now makes little difference to the number of satellites received (maybe 1-2 less/more).

Looking at the stats, it took around 16 hours and 15 minutes to upload the 9100 samples from this past weekend (it finished at ~04:43).

I could offer a section on the dashboard, where model D users could manually drop their CSV files (perhaps in a zip file, all together) and the server would identify the missing data and add it to the DB. Is this something any of you would like to use?

Absolutely! I spent a little over 24 hours away from home, so I have over 9100 samples to sync and that will likely take 15+ hours – hopefully it will be done by the time I need to leave for work tomorrow.
I’m not sure how the offline sync works now but couldn’t the model D itself upload a zip file (or even a simple tar file) of CSVs for offline data? It seems like it should be able to upload the 1MB of data for the 9100 samples much faster that way.

With regards to GPS antennas, I’ll look into other options. Do you have the part number or specs for the current antennas or know what the gain is?