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@srgdamiano
Active 1 months, 2 weeks agoForum Replies Created
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Is your goal to read all of your sensors and write to your SD card as fast as you possibly can? You could get faster readings by using concurrent sampling on the Decagons like this: https://github.com/EnviroDIY/Arduino-SDI-12/blob/master/examples/k_concurrent_logger/k_concurrent_logger.ino
Well, setting the profile to ‘1’ might work fine for the long term; I really have no idea. It just makes me a bit nervous.
And @mbarney, WRT buying new parts.. I’m still not happy with the failure rate of the XBee’s, but I don’t have any suggestions for anything better.
The newest firmware update includes the most recent u-blox update. [L0.0.00.00.05.08 App version 02.04, released 20May19] It requires using USB direct mode, but if you have the XBee3 TH dev board, it’s painless. I recommend updating.
There have been big warnings all over the place for the last several versions saying not to use bypass mode. Yet, despite that, the newest firmware actually includes a new command specifically for adjusting the underlying baud rate while working in bypass mode so we’re definitely not the only ones still using it.
I’m reading and testing more and I’m not so sure that I want to be setting the profile to “1/No Profile/SIM ICCID selected” for a Hologram SIM. While in the part of the documentation for the carrier profile command Digi says to use “1” for no configuration if you’re not connecting, in the steps of the connection process, they recommend this setting for European customers but not Americans. u-blox doesn’t provide any clarity at all on what the different profiles are. When Digi is describing the commands to manually select an LTE bands, they specify that bands can only be manually selected if the carrier profile is set to “1/No Profile.” So I started testing going back and forth between the different profiles using both the Digi commands (CP0-3) and the u-blox commands (UMNOPROF) and using both a Hologram SIM and the T-Mobile SIM I yanked out of my own cell phone. When I use my T-Mobile SIM, setting the carrier profile to either “1/None” in the XBee firmware or setting the UMNOPROF to “1/SIM ICCID select” does indeed make it “figure it out” and on the next reset if I query the profile the response is 5/T-Mobile. The Digi firmware doesn’t apparently doesn’t handle any CP response except 0/1/2/3 so it continues to report “1” but the u-blox has definitely locked on to T-Mobile. But, when using a Hologram SIM, the same magic doesn’t happen. The module can’t figure out what the profile for the SIM should be so it leaves it as whatever it was last selected to be. I was beginning to think that the command was just not working because I couldn’t ever get a response of 1 back to the “UMNOPROF?” command or see any change from it at all until I put in the T-Mobile SIM and saw that it go automatically to 5 after a request of 1. When left in transparent through a couple of resets and setting CP=1, it Digi sets the u-blox profile to 100=standard Europe. I’m strongly suspect that the u-blox “standard European” profile might actually mean “open up all the bands and either manually select the ones you really want or hope your SIM picks one” since Digi specifies that you must use CP=1 if you do want to manually select and u-blox says that selecting a profile will over-write all manual band selection. I’m just not so sure I trust the Hologram SIM to really stay connected when left to its own devices like that. I got most of the boards that had refused to connect to connect again by setting CP to 1, but I don’t know if the success was because I picked 1 or because I changed it at all. After all, all the boards I was messing with were boards that had previously connected and stayed connected for few weeks or months using no carrier profile at all. I think going forward I would prefer to specifically select the AT&T profile unless I know the board will be deployed somewhere with no AT&T signal.
One of the things I don’t get is that all of the modules I’m working with are ones that had previously connected fine without the carrier profile set. Why did they stop?
Grumble, grumble.. I just feel really, really dumb.
In the mean time, while I was stupidly missing the one setting I needed for the XBee3’s, I completely re-wrote TinyGSM to use CRTP instead of so many pre-processor macros, streamlined and error checked a lot of the functions of the various modems in the process, particularly for using GPS and RTC, tested all the modems I had with the new TinyGSM structure, and acquired, tested and verified ModularSensors functionality for both the SIM7000A and the BG96. I’m still waiting on a BC95G based module to arrive.
I also have spent several days trying to wrap my head around Zephyr and the build process for the developing and using the Nordic nRF9160 LTE SIP. It’s really grating me that it feels so difficult and I want to make it work just because of that. But I think that system is just going to be too complex for us to really use.
I opened the stack of XBee3’s that wouldn’t connect and, low and behold, setting CP1 got almost all of them to connect. I feel like an idiot. @ckillen, thank you so much for that catch. ModularSensors will be changed. I feel really, really dumb.
Interestingly, despite the face that I’m pretty sure there’s better service with Verizon here than AT&T, all of the modules chose to connect to AT&T.
I cannot believe I didn’t think about this setting! I am ashamed of myself. I will test it out. 😮
I’m pretty certain that the
CPcommand that the XBee3 implements is a pass through to the u-bloxUMNOPROF(Mobile Network Operator profile) command where setting 1 is “SIM ICCID select.” The operator profile encompasses both settings like the inital EPS bearer name [what the network first sees when you register, before checking the specific APN required by your SIM] and the actual LTE bands being searched. I had been always setting it to be AT&T because that seemed to be where Hologram put me most of the time and setting it specifically made the connection happen more quickly. I changed it to 0/Auto-Detect/SW Default a while back because people mentioned that they were in places with better Verizon signal and if the profile is set to AT&T, the modem won’t even look at the right band to find Verizon. I don’t remember ever noticing that bit of guidance in the manual with respect to modes 0 and 1 before. I wonder if it was added to the documentation recently.Interesting. Why did you chose the particle? Have they worked well for you? I got a few particle boards to tinker with but I haven’t actually even gotten as far as plugging them in.
@aufdenkampe, I’m sure that the Tagolas did better when it was new. You can’t really tell in my picture, but all of my bigger antennas are sort-of crumpled from being dragged back and forth in my backpack and getting shuffled around on my desk.
I would guess Sodaq’s decision to change antennas probably had more to do with suppliers and costs than anything else.
Most cellular antennas are very wide band or ultra wide band – they cover a lot of frequencies. And the major cell phone companies all use multiple LTE bands and frequencies. The last remaining GSM (2G) from T-Mobile’s is on band 2 at 1900 MHz: https://www.t-mobile.com/support/coverage/t-mobile-network, but globally GSM *could* be various bands anywhere from 350-1900 MHz. AT&T’s used to be on bands 2 (1900MHz) and 5 (850MHz) [https://www.frequencycheck.com/carriers/at-t-united-states] and I think those are the two most commonly used GSM bands globally [https://en.wikipedia.org/wiki/GSM_frequency_bands]. LTE can be on an even wider range of bands/frequencies – but if an antenna was already covering a wide enough range to get the main GSM bands, it can catch a lot of the LTE bands as well. T-Mobile’s main LTE band is the same band 2 that it uses for GSM. Verizon and AT&T’s “favorite” bands are 12 & 13, which are both 700MHz [https://www.whistleout.com/CellPhones/Guides/cell-phone-networks-and-frequencies-explained] – but they both also use bands 2 and 5 for LTE. Even if you had an antenna focused at only the 1900 GSM band, which I think is unlikely, it might do fine for LTE. I think 2G disappeared so they could use the same band space for LTE.
@ckillen – yes, that is correct.
You know, though, I’ve never actually done it. Time to walk down the hall to borrow Shannon’s soldering iron..
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