I am a beginner. I have an Arduino Mega 2560. I am using IDE 1.6.3. All worked fine, i did some of the examples. Then I bought a Wifi shield, original from Arduino. Installed it on the Mega 2560. Loeaded the example sketch to scan the networks. I alway get the message "wifi shield not present". I tried some other of the wifi examples, same result.
I searched the net, and it seems, some users have the same problem. Sometimes it is causes by a wrong firmware version of the Mega or the wifi shield.
First question: How can I find out the firmware version of the Mega, how can I find out the firmware version of the wifi shield?
Question 2: Which versions should they have to work together?
Also, I noticed there are 2 different pictures of the wifi shield from Arduino. I have the more modern version, that has an sd slot, lots of free space in the middle and a small switch next to the sd slot, labelled "serial select". what is it for? It was in the "usb" position and I left it there. Where can I find more information on this version of the wifi shield?