Even if it's simple ;), that would be easier for us with more infos.. Source of your GW firmware if you have not changed it. If changed, please post your changes. Source of your node sketch. Same as above. how it's wired with your roomba. you say it worked before, but it stops after couple minutes..?? So it doesn't work completely? Or it worked before, and what have you changed? and the logs Why not adding debug lines in your code to see where it bugs. Or use an external led if you want.