We are moving towards manufacturing our units at a larger scale, therefore we are trying to switch from Electron to the E-Series to make this process more streamline. We are using both the E-Series development kit and our own PCB for the E-Series chip itself and getting the same results from both.
The problem we are facing is that when using the Electron, we were having above 99% up time on our units. After switching to the E-Series, the up time decreased almost 10% when using the same code besides switching the pins. We are aware of the different U-Blox modules (3G vs LTE) and taken action to account for those modules as far as ensuring that appropriate signals are available for the units in the area that they are being tested and that they are not congested.
According to the datasheets, both units have the same power demands so I believe the power management shouldn’t be the issue if they are both connected the same way. Let me know if this is not the case!
Is there a different process when connecting, reconnecting, publishing, etc. that should be done differently on the E-Series rather than the Electron?
Any other suggestions (code/hardware) that we should look out for when switching from Electron to the E-Series?
It sounds like you’ve moved from the Electron to an LTE E Series – is that correct? I might’ve misunderstood you, but you do mention LTE. If that is the case, then LTE is kind of a different animal than 2G/3G – i.e. there might be things at play in the LTE cellular network that you never encounter with 2G/3G. (For one thing, the MVNOs are different.)
The 2G/3G E Series has higher current requirements than the LTE version, with 2G having the highest peak current draw (1800mA) vs. 800mA for 3G, and 550mA for the LTE module.
You should not have to do anything differently in your code between Electron/E Series.
Hardware-wise, having just gone through an exercise of putting together an E Series module-based cellular connectivity tester gizmo, and also knowing about some other things, I suggest:
Status RGB LED
both pushbuttons – or else, at least bring them out as pads that you can short. (However, if you provide a USB connector for the Serial interface, you might not need those since (with recent Device OS and CLI enhancements) you can access all of the E Series’ modes via CLI commands.
both USB interfaces, or else the ublox USB interface and one of the Serial interfaces brought out as pins. I say this because (a) it’s really hard to debug connectivity/user firmware issues if you don’t have access to one of the serial ports, and (b) there might be a need to update the ublox radio firmware in the future. (Since the ublox USB interface pin pads are on the bottom of the module, it’s practically impossible to get to those after the module has been soldered onto its host.)
We already had the hardware suggestions that you provided and have been continuing to debug this problem. We found after deploying the units, the units connectivity seem in increase overall, up to 95% and some to 99% up time. Though we experienced other (similar) issues with the E-Series connectivity.
We had deployed several units (3 E-Series LTE SARA-R410M) in a test site in the Denver, CO area and according to (https://www.opencellid.org/) that was provided by Marek, all devices are connecting to near cell towers with decent coverage for the area (~ -50 dBm). We have many Electrons near and around the site that had around (~ -70 dBm). All devices are running the same software and are running off the same power setup, though some Electrons are on different firmware version.
The three E-Series devices went down at the exact same time at 2019-11-19 07:15:00 (UTC). The rest of our devices, Electrons, seems to have no down time during or around this time.
Is there anything that occurred at this time that caused these devices to go down?
Could it be the LTE cellular network and if so, how do we find out?
What are some debugging methods for connectivity that we can go through to debug what is going on?
Any other suggestions that could affect connectivity on E-Series vs. Electron?
Hi Jeffrey - have you created a support request about this outage? (It may have already been taken, just wanted to check). The Community is the best place to discuss almost everything, but the detective work around cellular issues like this usually involves some sensitive data exchange (deviceID/ICCIDs, location information, etc…).