Same project on various MKR boards ....

Hello.

My project goal is to get some measurement out of a 4-20m 24V particles counter and send the measurement to an external web server, at regular interval (few hours). I need to write and test with several communication options : Wifi/GSM/LORA Wan. Each board will have a SD Card/Flash memory shield added in case the coms option is temporarily unavailable.

The final goal is to be able to make about a hundred of these, which will be deployed in a couple dozen sites.

Each board will have a slightly different configuration (stored in the flash memory) things like identifier, local Wifi SSID/Password or GSM credentials or LoraWan ID – depending on the case, I need an easy way to do this configuration on site.

My initial thought was to write a small webserver but that would work great on Wifi, medium great on GSM and is a nono on Lorawan, another option is to add a mkr Ethernet shield – but on 100 boards this adds 1600€ to the budget.

I am trying to keep the largest amount of code possible common to the various platforms so I am wondering if Is it a good idea (or not) to try and use a communication via the USB link ? Can it be used to readwrite simple questions and get simple answers ? Is it more clever to use the serial interface (pin 13/14)

Any other idea ?

I have tried to keep this as short as possible whislt providing some context. I hope I succeeded.

Any answer or suggestion will be gratefully received

Didier

If you use the USB link, you will need a PC connected to each board ($$$$). It is probably the best way to configure your boards, but not the best way to transmit the data to your database. You could configure your board using the serial monitor to send command to write SSID/password, whatever to a file on the SD card and then the board would always use that to configure itself and operate