With the help of Paul Fertser I was able to install OpenWrt onto my Meraki MR18 access points using a novel appropach of using OpenOCD on a Raspberry Pi. I've had a go at writing up the process here:
Also, I summarised on the existing MR18 page:
I have some photographs to add, but at present I "don't have enough rights to upload files". Would these be desirable and, if so, could someone grant me access to upload? Thanks
Thanks, that's clear now. I used the link in the given URL.
It's a little unclear because in the wiki editor, the button to insert an image opens a "Media files" dialogue which one assumes to be the media namespace. It makes sense now.
I've updated the guide with photographs.
I have fixed a typo and tested using a Raspberry Pi Zero W, the serial port changes to /dev/ttyS0