$ cd firmware
$ export MIX_TARGET=rpi
$ mix deps.get
$ mix firmware
# first time
$ mix firmware.burn
# later on
$ mix firmware.push 192.168.1.4 --target rpi
# connect to pi and ping store
$ iex --name h@192.168.1.7 --remsh firmware@192.168.1.4 --cookie secure
iex(firmware@192.168.1.4)1> :net_adm.ping(:'store@192.168.1.7')
:pong$ cd store
$ rebar3 get-deps
$ rebar3 compile
$ rebar3 shell --name store@192.168.1.7 --setcookie secure
# ping firmware
(store@192.168.1.7)1> net_adm:ping('firmware@192.168.1.4').
pong