Didn't intend to send the first reply. Your method sounds good. You might think about just having the sensors transmit at a fixed time plus a random time for each unit. Not worry about two way communication. The percent of collisions are about equal to the percent of the sum of the transmit times to the total time when small. So if each unit transmits 20 ms each second, the collision rate will be 60/1000 or 6%. Bill ----- Original Message ----- From: "Dumitru Stama" To: Sent: Saturday, February 11, 2006 11:02 AM Subject: [EE] Anticollision algorithm > > Hello guys, > I want to implement a few wireless sensors in my home and i was > thinking about using nordic-based modules like the ones sold on > sparkfun.com. My question is how can i implement a working > anti-collision communication between the sensors and base station ? > If three sensors broadcast at the same time then i might have a > problem. I was thinking about a token sent by the base station to one > sensor after which it waits a period of time for the feedback and then > move to the next sensor and so on. Is this a good way of doing things? > I can also detect if on sensor has been disabled very easy and maybe > (if it is a security system) to issue some warnings if the problem > is still there after a few minutes or a few unsuccessful tries. > > Dumitru Stama > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist