Set Static IP raspberry PI

edita
 sudo nano /etc/dhcpcd.conf

y ahí configuras. Ejemplo:

interface eth0

static ip_address=192.168.3.242/24
static routers=192.168.3.10
static domain_name_servers=8.8.8.8

interface wlan0

static ip_address=192.168.1.142/24
static routers=192.168.1.2
static domain_name_servers=192.168.1.2

Luego guardas y renicias