use CCA enable before sending something out. On Fri, Oct 29, 2010 at 1:44 PM, Simon Eberz <[email protected]> wrote:
> This should not be the case, as packets are only sent as a respone and > after a short waiting period (20ms). > Thus, the two motes can never send at the same time. > > > Unless you have some randomisation before you transmit packets, sounds > like > > your packets are interfering with each other. SendDone can be signaled > even > > if packet's lost in propagation (I think..). > > > >> -----Original Message----- > >> From: [email protected] > >> [mailto:[email protected]]on Behalf Of Simon > >> Eberz > >> Sent: 28 October 2010 18:42 > >> To: [email protected] > >> Subject: [Tinyos-help] Broadcast packet not received by all motes > >> > >> > >> Hi, > >> > >> I'm implementing a simple message exchange between two motes > >> (to measure > >> the RSSI, but this is not of interest) and > >> send the messages as broadcasts. > >> I'm using the TinyOS Basestation application with the Listen-Tool to > >> check which messages have been sent. > >> Here's the problem: I have two motes (call them A and B) with nearly > >> identical code flashed to them. > >> A sends a message (broadcast), and after that each mote will > >> send a new > >> broadcast after receiving a packet. > >> All messages sent by A are also received, and thus displayed, by the > >> BaseStation-mote, and the LEDs indicate that > >> all messages are also received by B [otherwise only one > >> message would be > >> sent anyway]. > >> But, when B sends a message, it seems to be received by A [as > >> A responds > >> with yet another packet], but is not displayed > >> by the BaseStation-App. I tried to verify this by flashing a > >> third mote > >> with custom code, same issue. > >> If I just call the SendProbe-method [see below] on mote B it > >> works fine > >> and switching motes doesn't help either. > >> LEDs suggest that the SendDone-Event is triggered on both motes. > >> Ultimately, it seems that the broadcasts are only received by > >> the mote > >> from which the last message was received (?). > >> Is there any property of broadcasts that I am not aware of? > >> Here is the (relevant) code I use: > >> > >> void SendProbe(){ > >> probe = (ProbeMsg*)(call Packet.getPayload(&pkt,NULL)); > >> probe->source = 1; > >> probe->counter = counter; > >> call AMSend.send(AM_BROADCAST_ADDR,&pkt, sizeof(ProbeMsg)); > >> } > >> > >> event message_t * Receive.receive(message_t *msg, void *payload, > >> uint8_t len){ > >> if(len==sizeof(ProbeMsg)){ > >> probe = (ProbeMsg*)payload; > >> call Timer.startOneShot(DELAY_BETWEEN_PROBES); > >> } > >> return msg; > >> } > >> > >> event void Timer.fired(){ > >> SendProbe(); > >> } > >> > >> > >> Thanks for your help > >> _______________________________________________ > >> Tinyos-help mailing list > >> [email protected] > >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/t > > inyos-help > > > > Please consider the environment before printing a hard copy of this > > e-mail. > > > > The information contained in this e-mail is confidential. It is intended > > only for the stated addressee(s) and access to it by any other person is > > unauthorised. If you are not an addressee, you must not disclose, copy, > > circulate or in any other way use or rely on the information contained in > > this e-mail. Such unauthorised use may be unlawful. If you have received > > this e-mail in error, please inform us immediately on +44 (0)118 986 8601 > > and delete it and all copies from your system. > > > > Thales Research and Technology (UK) Limited. A company registered in > > England and Wales. Registered Office: 2 Dashwood Lang Road, The Bourne > > Business Park, Addlestone, Weybridge, Surrey KT15 2NX. Registered Number: > > 774298 > > > > Thales UK Limited. A company registered in England and Wales. Registered > > Office: 2 Dashwood Lang Road, The Bourne Business Park, Addlestone, > > Weybridge, Surrey KT15 2NX. Registered Number: 868273 > > > > > > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > -- Wasif Masood
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