Am Mo 20. Oktober 2008 schrieb Alastair Johnson: > Werner Almesberger wrote: > > I order to evaluate the impact of the AT%SLEEP=2 work-around, Joerg > > asked me to measure how the sleep mode affects the current drawn by > > the system. > > > > Test setup: > > > > - device is idle but (for convenience) not suspended > > - GSM is active and has registered with the network (AT+CFUN=1, > > AT+COPS=0) > > - the test setup does not suffer from #1024 > > - power is supplied to the battery terminals from a lab power supply > > set to 4.0V > > - USB is not connected > > > > Battery current of the whole system in mA. Values are from measurements > > averaged over about 15 minutes each: > > > > at%sleep= avg min max samples > > 4 96.0 91.6 198.0 20006 > > 3 98.4 91.6 214.6 21432 > > 2 102.2 97.6 209.3 21428 > > 1 104.0 101.9 197.2 21352 > > 0 120.3 118.8 213.0 21452 > > > > Integration period is one power line cycle (20ms). There are transients > > much faster than 50Hz. E.g., sampling at 2.5kHz finds more noise but > > does not change the difference in the averaged value: > > > > at%sleep= avg min max samples > > 4 95.1 63.1 242.5 210207 > > 3 97.1 62.8 242.9 215460 > > 2 101.4 68.7 243.4 208230 > > > > Note that this is an idle but not suspended system, hence the large > > minimum current. > > > > So the difference between sleep=2 and sleep=4 is about 6mA. Joerg > > mentioned that the idle current of the GSM subsystem should be 4mA, > > so this would be an increase to 250%. > > > > Andy, you once measured the power consumption when the overall system > > is perfectly suspended. Do you still remember how much it was ? > > > > - Werner > > Can you repeat the test on a handset that is suffering from #1024? I > suspect that the frequent reregisters increase power consumption, but I > don't have the equipment available to make the measurements. It > certainly produces more instances of GSM interference on my PC speakers > which suggests more transmit operations. If this is the case then for > those wth #1024 SLEEP=2 may be no worse, or possibly better, than SLEEP=4.
that's the idea behind Mickey's recent bandaid, switching to SLEEP=2 on detecting #1024 behaviour /j
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