I am trying to get a SARA-R5 MM function board to connect to LTE in the eastern Carribean. The Global SIM from Hologram has coverage where I am. Both Antennas that I brought have coverage with the local frequency bands listed by the local carriers (Digicell and FLow). The hardware has been happy for weeks in Colorado.
Weirdly, the RSSI is stuck at 99 and the GPS is not getting a signal… Could the module have died? (I have also tried a second SMA adapter cable thingy…)
What does a value of 99 mean?
Obviously, in retrospect, I should have brought a second module with me on this trip, but given the solidity of the hardware over the last few weeks I assumed the problems would likely be around network registration etc.
Am I missing something? Is there some configuration step I might be missing that would give this RSSI number? I even went back to working through the example programs. Below is what I get for Example 3.
Any ideas?
thx,
Doug
SARA-R5 Example
Press any key to begin
SARA-R5 connected!
Network profile set. Ready to go!
RSSI: 99
Network registration: Registration unknown
Available PDP (Packet Data Protocol) APNs (Access Point Names) and IP Addresses:
Does it still stay at 99 if you block its signal? (put under metal, concrete, etc structures)
Also note: “Note - Please read before purchasing!: The SparkFun LTE GNSS Breakout - SARA-R5 uses the “00B” product version of the SARA-R5 module (specifically the SARA-R510M8S-00B-00). LTE NB-IoT Radio Access Technology, and the LTE FDD bands: 66, 71, 85 are not supported by this version. Refer to the SARA-R5 datasheet for more information.”
Do the cell carriers where you are happen to use those unsupported bands?
I think I likely know what’s going on here… It seems that the local cellular provider has not rolled out LTE-M yet (doh!). In fact, they are still providing much of their coverage on 2G…
I simply did not anticipate that this would be the case, which is my fault. I’d checked LTE bands, but hadn’t thought to check that their RATs included LTE-M.
The modem’s use of “99” as the signal strength parameter for when it doesn’t understand the signal was partly what tangled me up…
Thanks for the update. I don’t think there’s anything we can do to help? But if you think there is, please let us know.
The only suggestion I have is to check the “const mobile_network_operator_t MOBILE_NETWORK_OPERATOR = MNO_GLOBAL;”. Maybe one of the other MNO_ options would be more successful?
I did have a long discussion with a customer in Italy on a similar issue. You might find it useful?
Thanks for checking in. After a fair bit of head-scratching I’ve decided to roll-my-own function board using the LARA-R6001D which, hopefully, will give me enough cellular connectivity options to deal with various weird juristictions and sketchy cellular roll-out roadmaps. It won’t be as low-power, but I think I’ll change my upload strategy somewhat to buffer more data, then waken up and talk to the cloud (using MQTT probably).
This LARA module lacks GPS, so I’m including a uBlox Max 10s module to provide GPS data. I’m using the function board footprint for my PCB, so that I can replace the SF board without having to re-do the main board of my project. The design is almost complete, so by the time I get PCBs, assemble and test it, it will probably be a month at least before I’m ready to start playing with it in earnest.
I live only a few miles from Sparkfun so, when possible, I buy their stuff. In this case, however, I wanted the global version of the LARA-R6, so the SF LARA board isn’t so good (plus the micromod form-factor is convenient).