I have actually started on this type of project. I am using two Pi’s in a stack, one for Outernet, and another one for RACHEL. I am using the Outernet Pi for the access point and slaving RACHEL off of it. I got the Pi’s talking on the network level, but I cannot get the Outernet Pi to allow HTTP traffic to the RACHEL Pi. Once done, both Pi’s, six 12 motorcycle batteries, PicoUPS, and some various other power converters are going to be stuffed in a semi-weather proof box for deployment. The box will take any DC input from 9V to 18V DC, but needs 13V to recharge the batteries. So far it has run two days and only dropped .6V over those days without being recharged.
I think my problem lies with dnsmasq, but since it is not a standard install, I cannot seem to get it working right. Right now it is setup like a Pi router, WLAN is setup straight out of the box Outernet, the ETH0 on both Pi’s are setup on their own private subnet with static IP’s. And they can talk to each other on that subnet via SSH without issue, but as soon as I try to http to the RACHEL Pi that is where the wheels come off. I am sure it has something to do with dnsmasq if I could just find where the conf file is located since it is not in /etc/dnsmasq/dnsmasq.conf.