Hi and thanks for reading and offering your input...
I've been working on developing an ESP32 based SBC with a cellular modem, i.e. using PCBArtists' ESP32 LTE 4G Gateway product.
I've been able to piece together the necessary code to connect over cellular using PPP and leveraging both "data" mode for IP comm and
"command" mode for issuing AT commands, e.g. for sending SMS text messages.
I'm still struggling to get the rest of the functionality working (i.e. sending SMS, receiving SMS, and handling async events like SMS msgs that come in), but the
questions I'm asking here is more about IoT simcard providers and simcard use.
Clearly, I'm not going to get very far without a simcard in the modem and I've had issues with the hologram.io cards I have. However, I generally
like the portal, i.e. dashboard, concept they have but it's lacking. So, I'm hoping others have had experience dealing and using IoT modems and
can offer some advice or recommendations. Here are some questions:
1) Any general advice regarding what to look for in simcard vendor?
My near term use cases include:
* testing software I develop that will send short data updates over websockets, tcp/ip and udp sockets--no video, no large data, etc and not too frequently.
* send and receive SMS Text messages M2M, however for testing will send/receive from on my phone
* usage in typical populated areas so will have access to tier 1 providers
* I don't expect more than 1 MB/mo for this near term
* I'm based in US and will not be dealing with international
2) I've already run into some odd things like one day my test code works with a given simcard but next day it doesn't. Hologram.io has a
"dashboard" which would seem to be helpful when trying to understand why SMS texts are not arriving on my phone, but data is not updated
frequent enough for debugging or understanding connectivity issues--dashboard says text was sent??
What experience might you relate regarding this aspect of getting a project working?
3) who would you recommend for a simcard provider that has good portal support for debugging sms text messaging?
Thanks in advance