I need to have a communications system for relaying logged data on a daily basis from a freight container located anywhere. It will also have GPS signal.
I am looking for a low cost solution to connect some modem to a processor and have the processor automatically send data at end of each day.
I do not know much about mobile networks or protocols but suspect this is the way to do it.
I think I need a 4g modem. And I think I need to contact a supplier of mobile plans who will sell me a sim card and charge me per month fee. The amount of data over a month will be trivial but I still want a low cost solution.
Can you suggest a modem and resource how to program it to send data to some central computer system connected to the internet?
Also - can I send data to it from the central computer system?
You are probably looking for some NB-IoT (LTE Cat.NB1 ) module. This technology has been created to allow for duplex communication between the device and the Cloud on systems with constraints on their power supply (i.e. standalone devices powered from batteries).
However, bare in mind that the actual payload transmitted must be short (so low power goals can be achieved)
I used an u-Blox module in the past (SARA-R410M02B) but you might want to have a look at the SARA-N2 series which I reckon is better than R4. Other manufacturer you might want to look is Quectel (I’ve heard their modules are pretty good).
There are, of course, some other manufacturers, but I have no reference about them.
With regard to the SIM cards, have a look at: https://hologram.io/
Hi Clem. A development board is a great way to prototype and build / prove your solution. I’d suggest an Arduino MKR NB1500 might be a good place to start, I have had success with these using CatM1 / NB comms. And you could look at different interfaces (eg. serial) to the devices you need to get information from, the MKR series has some good shield options there and the libraries to support a pretty quick development effort. Good luck with the project. Cheers, Steve B.