I’d like to better understand what the behaviour of the Notecard is when reception is poor or non-existent - does it just keep trying to connect until the battery is dead? Or is there some firmware smarts to make it go to sleep and try again later? I’d love some more detail on this?
Also, on a somewhat related topic, what exactly does Hub.set: Outbound and Inbound do? I understand that it makes the Notecard connect to the cloud at the minimum intervals specified, but what does it really do? Does it sync all the saved notes which weren’t sync’d before? I ask because I am in a relative poor reception area and have occasions when there is no data sync for >12 hours. However I do see {“why”:“periodic outbound sync due”} in my Events, but no actual data.qo syncs. If I then move the notecard to a better reception area, there is still no sync, not for days, until I power cycle. Does this mean the Notecard hangs and can’t get itself out or is this a problem with the MCU/my code? I’m using the pseudo_sensor library to make the Notecard wake the MCU every 15-min so the MCU effectively reboots every 15min. I know it is related to reception somehow because several Notecards will “hang” at the same time and fail to sync data there after. Wondering if someone can help me understand what is going on?
Hi @rberkelm,
What you’re witnessing is likely the Notecard being placed in what we call a “penalty box”. If the Notecard is repeatedly unable to connect to a cellular network, it is not allowed to even attempt a new connection (this is in place to prevent unnecessary battery drain). We have a full doc article available here that I would recommend reading:
Which model of the Notecard are you using? And where are you located (country)? I ask because if you’re in an area with very poor reception, I highly recommend using one of our wideband Notecards: the WBNA Notecard (North America) or WBEX Notecard (EMEA) as those allow for the usage of an additional diversity antenna. That can make all the difference.
Rob
Hi @rberkelm, piping in… operating in the Caribbean I am almost constantly in a borderline reception area.
What I learnt over several years is
- as @RobLauer said, WBNA is a must
- you need a quality external antennas – the stick-on kind is fine (there is a thread somewhere in the forum) – and you get what you pay for.
- if you have infrequent events on the notecard side, write notecard side code to send a “I am alive” every 6 hours (for example), track it for a while on the cloud side.
On the positive side, I tried everything for remote communications over the years and credit to Blues, if there is a way to get a packet out, they’ll find it (roaming, flaky cellular towers, poor signal, frequency changes, etc.).
Thanks Rob for opening my eyes to penalty boxes! That is a very sophisticated way of dealing with spotty connectivity and it explains a lot - thank you!
I’m in Australia so for me it’s pretty much the global NBGL-500 version or nothing. So a few follow-up questions:
- When the Notecard is in a penalty box, does it release the EN pin (ie make it go high)? I notice that my MCU is awake when in this mode whereas it should normally be disabled by the Notecard in Sleepy sensor mode.
- Can you also please confirm that if the Notecard does an Outbound connect, that it will also sync any notes it has at that time?
Thanks for chiming in Francois! Yes, I am going to have to learn to make the most of my poor connectivity locations. I’m thinking a directional antenna may be a good way to go in marginal areas. When you say:
Isn’t that the same as setting an Outbound sync interval?
@rberkelm Yes, setting the Outbound sync interval will lead to the same result. What I found is given notecards sprinkled in borderline areas, it was worth creating a basic web page showing those that missed their 6h check-in, and how long since. If you also have power outages as I do I track the reboot/restart to separate those from penalty box issues.
I assume when you say EN pin you actually mean ATTN? If so, how have you configured the ATTN pin with card.attn? You can check with this request: {"req":"card.attn","verify":true} if you’re on firmware >= 3.2.1.
Also, FYI the WBEX Notecard should be supported in Australia (based on my cross-referencing of LTE bands supported with the modem datasheet).
Rob
Thanks Rob. Great to hear the WBEX Notecard might work down under - very encouraging! I had a look at the freq bands and agree, it should work. I’ll order one and try. Do you have any tips/suggestions on implementing a diversity antenna system? Two similar omni directional antennas? One omni, one directional? I’m getting best performance from a small whip antenna so far, based on RSSI and RSRQ readings.
As for the EN pin issue, yes I do mean the ATTN pin on the Notecard. Forget what I said, it turned out to be a software issue on my side. My apologies.
@rberkelm,
I’m in Oz…
I got the NBGL-500 as I figured it had the greatest change of working (LTE Band 28), plus was what someone else I know was using.
I’m in a very fringe area and was having issues with connectivity and data usage… with lots of help from Rob and the team we did narrow it down to bad/very low signal strength and quality.
I have been running a WBEX-500 (thanks Rob) for a couple of weeks now with the Notecarrier antenna and the blues molex antenna on the diversity port… Has been performing a lot better… My WBEX is connected to Vodafone UMTS 900MHz…
For the WBEX, I’m looking at using 2 small omni’s (the same) once I get to the next phase.
Update: Just connected to WBEX and it’s currently running in LTE Band 3 on Vodafone
Hope that helps…
Neil
@rberkelm - re: the antenna question, I’ve had the best luck with this Molex 209142 along with a dual LTE/GPS Pulse antenna like this.
@ndavey, @RobLauer and @Francois - Thanks for the in-field experience! I’m super keen to get started with WBEX.
Those patch antennas can be good… just not when you do what I did… i.e. inside the enclosure 10mm above the ground plane of my carrier board. See this article: https://www.mdpi.com/2624-6120/3/2/21/htm.
