Is there a method to query the sim card itself for any details etc.
Reason I ask is that I live in Canada but still have some quite recent UK sims from PAYG that have credit left on them.
In my dual sim phone the UK sim asks if its OK to connect to a non native network and would ask which network.
Am sure there would be other scenarios too where the sim may not work on a network transition.
Forgive my noobness on this one as its a new foray into an area I have only dealt with on phones.
There are no API's in the MKRGSM library to do this currently. The MKRGSM will attempt to connect to any network the SIM knows about, whether it's roaming or not.
1) There is a GSMScanner class that allows you to get the current carrier.
2) You could manually send AT commands to the u-blox SARA-U201 module https://www.u-blox.com/sites/default/files/u-blox-CEL_ATCommands_%28UBX-13002752%29.pdf (https://www.u-blox.com/sites/default/files/u-blox-CEL_ATCommands_%28UBX-13002752%29.pdf)
I have two SIM cards both on GiffGaff. The top one in this image does not work but the bottom one does
Both work when placed into phones.
Thanks for any help.
The bottom one has the pads closer together clearly.
Only thing I can think of is stray energy is able to go between pads somehow.
Quality standard for a phone is so much higher that items from the hobby field and that may explain why they both work in a phone.
If it were my card Iwould maybe try score between the tracks a little but that is something for you to decide as it may leave the card inoperable and would require a very delicate hand.
Is there any variation in physical size ?
The top one is also a NANO card punch out type which are the newer ones and always made to a higher spec.
I'll give scoring the card a go in the coming days.
There is a slight difference in size. The bottom working one is slightly larger.
I experiment the same problem !
Is it a problem of the SIM card holder on the MKR GSM board ? Too old to match the contact surface of a nano ? (Surfaces are not exactly in the same design).