As an example.
I have 100 devices of one product type in their own locations.
I want to do an mass firmware update to all of them.
Suppose each device has it’s own API, MQTT Login, or Password (Specific to the device).
How could I retain those credentials during mass updates for each device?
Is there a smart way of achieving this.
A firmware update does not reset the device EEPROM, so storing data there should be safe.
That's awesome! Thank You @ScruffR. I have been reading your stuff for a while now. Super talented! Do you have a reference for basic EEPROM info?
I was also curious of a good way to flash 100 units and documents API keys and such in a efficient way.
Sure https://docs.particle.io/reference/firmware/photon/#eeprom
But, how did make sure the data wasn't lost in case of power failure so far?
That greatly depends on what you want to send.
Flashing firmware to 100 units in bulk is best done via the Particle Console | Build your connected product.
Sending individual data per unit - naturally - has to be done on a one-by-one basis, but with a dedicated function and some script that can call these functions and feeds some stored data to it that shouldn't be too much of an effort.