Has anybody implemented a neural network on a aduino?
I don't know that much about them is it possible to train one and then put that training onto a arduino?
I don't know that much about them
Seems like you need to correct this. Then, you'd know the answer.
In short, though, it depends on what the network is, and what it is supposed to be doing. A few more details would be needed before this vague question can be properly answered.
Because of the RAM and the CPU speed they will be somewhat restricted, but I did one simple neural net that I trained to receive input from four buttons and display the binary value of those as decimal on fifteen LEDs.