Eagle auto routing - absolute newbie question

I just did the sparkfun Eagle tutorials online. Great bit of work guys. But when I hit the auto route button, only half of my circuit auto-routes. Why is this?

Apologies if this sounds like a stupid question. :oops:

I thought it might be because it can’t find a way without adding links, then I thought that the via costs were set too high. I set them all to 0 and still it only does half the circuit.

It’s not a very good autorouter. Try setting the grid to 5 mils, the Pulsonix autorouter I use always routes with 100% completion or close to it with that setting.

Leon

you’re better off hand routing…

However, if you insist on using the autorouter, parts placement is going to be critical. Try playing with your placement. rotate chips around until the airwires cross the least. try to group sub-circuit elements together. use a ground polygon around the whole board.