Hi Tony, There is a reason behind this, but you can adjust it to meet your application's needs.
The radio shares the SPI bus with the flash, so applications that access flash alongside radio will contend for the SPI bus. In earlier versions, the Tx node would release the SPI bus between the transmission and listening for an ack, which would allow the flash to acquire the SPI bus in between. This meant the Tx node wouldn't have access to the SPI bus to hear the ack. Because either the transmitter *or* the receiver could have flash accessing the SPI bus causing the acknowledgement to be delayed, the solution came in two parts: 1) don't let the transmitter release the SPI bus when it's waiting for an acknowledgement, and 2) extend the ack wait period to handle the case where the receiver can't acquire the SPI bus in time. If your application does not use the SPI bus (or any other peripheral on SPI0) then you can safely lower the CC2420_ACK_WAIT_DELAY value and maintain the same acknowledgement reception reliability. -David -----Original Message----- From: Tony O'Donovan [mailto:[EMAIL PROTECTED] Sent: Monday, September 03, 2007 4:07 AM To: David Moss Subject: Re: CC2420 lpl Hi David, Sorry for annoying you with more questions. In the tinyos 2.02 version of the cc2420 libs you've changed CC2420_ACK_WAIT_DELAY from 128 jiffies to 256 jiffies, nearly halving the possible send rate when using acks. I was wondering what the reason behind this is. Thanks Tony _______________________________________________ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
