By default drone is the access point and the DHCP server on the address 10.0.0.1. It supports one client only (dnsmasq is configured to serve an IP range from 10.0.0.2 to 10.0.0.2, e.g. single address). So your device should automatically obtain 10.0.0.2
Don't forget, that any MavLink Ground Control Station is the server, drone is the client, ArduCopter.elf daemon is constantly trying to establish UDP socket with the address/port configured in the startup script (/home/erle/apm.sh), so your GCS device should allow incoming connections on the configured port or have the firewall completely off.