On May 13, 2009, at 10:30 AM, Carmine Ambrosino wrote: > Hello everyone, > I'm working with telosb platform (with MSP430f1611 uC) and I > noticed that time between the call of the Read and the sleep of uC > is about 40 ms. In particular the time between the call of the Read > and the call of ReadDone is long (like 16 ms). Why? I look the > tutorial lession (TEP101) and the ADC is a SAR 12 bit and the clock > is 5 MHz and so I expect a much lower time!! What am I ignoring? > What should I consider?
Kevin Klues' paper in SOSP 2007 goes into details on the telosb ADC timing. The voltage reference requires approximately 17ms to warm up. So while the first reading has a long latency, subsequent reads (before the timeout) should be much faster. Take a look at Section 5.2, Table 3, and Figure 9. Phil _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
