Is the Tinker firmware special, when using STARTUP?

I know that the Tinker firmware, used for the online interface, and Android App can be used with 3rd party SIM’s.
https://docs.particle.io/support/particle-devices-faq/electron-3rdparty-sims/

It uses a line of code that instructs the Electron to connect to a 3rd party network, like so:
STARTUP(cellular_credentials_set(“fast.tmobile.com”, “”, “”, NULL));
https://raw.githubusercontent.com/rickkas7/particle_notes/master/tinker-apn-tips/tinker-apn.cpp

It sounds from the instructions that the Tinker firmware ALWAYS needs to be flashed when changing the SIM and Network, before uploading a custom firmware that also includes the same STARTUP() macro.

My question - because I can’t test it right now:
Using offline firmware uploading via the CLI, can I completely ignore the Tinker firmware flashing stage when uploading new programs and changing SIM’s to and from the Particle SIM and 3rd party SIM’s?

(My confusion is that it sounds like the Tinker firmware flash changes something that general program uploads don’t change, even when they include the SYSTEM() macro… and as such when changing the SIM in the Electron I need to flash the Tinker firmware, THEN upload my new program.)

The Tinker firmware is just for illustration purposes so you can have the same setup experience as with the Particle SIM card.

On Gen 2 devices (Electron, E Series) you must include the STARTUP(cellular_credentials_set(...)) call in all user firmware that runs on a device with a 3rd-party SIM card. You will also likely have to add Partilcle.keepAlive(...) call.

It’s not necessary to install Tinker with APN first, you can go right to your own firmware that sets the APN.

Excellent!

Thank you for explaining it to me. :smiley: