Changing WiFi AP on already-configured boot image

[G8FKL]

Having changed ISP and router, is it possible to change the access point SID and PSK on an already-configured boot image? I have lost my backup file and have no other record of my PiStar config other than the bootable SD card. I am using a MacBook and am unable to simply copy a revised wpa_supplicant file into the Boot folder, nor am I keen to start again from scratch.
TIA - GeoffT.

[G8SEZ]

Visit this page:

https://www.pistar.uk/wifi_builder.php

enter the information into the fields shown and submit.

Put the resulting output into a wpa_supplicant.conf file placed in the root directory of your SD card after shutting down the Pi, then re-insert the card and boot the Pi.

This will be moved into the correct place during the boot process.

[G8FKL]

Thanks Brian.
I did try that but with the SD card image mounted on my MacBook I am unable to write anything into the root directory.
Maybe I should try Windows?
Geoff (GM8FKL)

[G8SEZ]

Ah, didn't know you only had an image file. ISO?

Can you not write a new card from the image and then mount that on the Mac?

[KN2TOD]

Having changed ISP and router, is it possible to change the access point SID and PSK on an already-configured boot image? I have lost my backup file and have no other record of my PiStar config other than the bootable SD card.

Ah ... if you have a bootable SD card, why not just boot it and then look for the Pi-Star-Setup access point?

[AF6VN]

I'd think the Mac should, at least, show the small FAT partition on the SD card (it may or may not show the EXT3 or EXT4 partitions) -- THAT, if I recall, is the BOOT partition (containing the model specific device trees, etc.) and is where the generated wpa_supplicant information file should placed.

On booting the SD on an R-Pi, the Pi-Star software will look at the FAT partition for customized files -- like the wpa_supplicant information -- and will copy/update the real wpa_supplicant file that is on the EXT# partition.

[G8FKL]

Thanks all for the help and advice. Finally tracked the writing to FAT partition problem down to a faulty uSD/SD card adaptor stuck in read only. Now fixed and connected to new Starlink router.

[KN2TOD]

Thanks all for the help and advice. Finally tracked the writing to FAT partition problem down to a faulty uSD/SD card adaptor stuck in read only.

Thank YOU for letting us know: the one "solution" none of us thunk to pursue: Technology moves in mysterious ways.

[G8SEZ]

Thanks all for the help and advice. Finally tracked the writing to FAT partition problem down to a faulty uSD/SD card adaptor stuck in read only. Now fixed and connected to new Starlink router.

Ah, yes, those little switches are rarely used but can fail despite that.