Arduino Ethernet => Raspberry Pi Ethernet => Wifi

Hi guys,

is it possible to connect an Arduino via Ethernet with a Raspberry Pi which also provides a wifi AP? My idea is to have an Apache- and a MySQL-Server running on the rasp. The arduino should communicate with the rasp over the ethernet an get some JSON requests generated by a script running on the rasp. On the other hand I need a way to spread a wifi AP to get a connection with a tablet or smth else to the local Apache rasp to fire up some commands to the Arduino. So I need a way to get a communication like this:

Arduino Ethernet <=> Raspberry Pi Ethernet and Wifi <=> Tablet, Smartphone or what else (browser)

How do I’ve to configure my Raspberry Pi to accomplish this? Thanks for your help in advance!

It is kinda a RPi issue, but the easiest way is connect the Arduino ethernet and the RPi to the same wireless router.

I shouldn't give away all my secrets, but this router is my favorite.

It provides power through the usb ports for both devices, and allows a serial connection to the Arduino over a TCP connection with the router. But it is not for the beginner. It does not come ready to run "out of the box".

edit: Did I mention it needs an additional radio module? And it is expensive. You will have over $200 invested in the router and additional hardware by the time you are done.

Thanks for your reply. I already got the needed components, so I would stay with my rasp pi and my compatible usb wireless stick for the AP mode. But you are right, the question is more linux specific for the routing.

Then the routing on the Arduino ethernet is easy. Assign an ip to the RPi ethernet interface (like and use an ip in that subnet to the Arduino (like and use the RPi ip address on its ethernet interface as the gateway.

Insure the RPi wifi device has a different ip subnet.

Buy an old router off ebay for $15.00 and reflash it with

Buy an old router off ebay for $15.00 and reflash it with

I need a compact the RPi ist the way to go! :wink:
I will try SurferTim's solution.