Thank you for your fast answer. The problem is, we use sntp time synchronisation and get therefore wrong time stamps. Is it good idea just to change RTC_TIMER_HZ or it would cause more another problems? Best, Elena
On 06.07.2017 10:41, Ugo Maria Colesanti wrote: > The TimerMilliC in RFA1 is connected to the 62500Hz Symbol Counter which is > not > a power of 2. You need to multiply 5120 by 62500 and multiply it by 65535 > which > should give you 4883 after rounding. > > Ugo > > On 6 July 2017 at 10:18, Elena Chervakova <elena.chervak...@imms.de > <mailto:elena.chervak...@imms.de>> wrote: > > Hi all. > We work on some experiments with TinyOS timers on RFA1 and RFR2 > platforms. In > both cases, there is a significant time deviation from the set timer > interval > and the actual time. > > To analyze the behaviour, we set a timer to 5 seconds using the > TimerMilliC > component by calling: > > call Timer.startPeriodic( 5120 ); > > for this we have a constant error of 0.25 seconds per timer event. This > results > in a deviation of 0.5 seconds per 10 seconds which is too much for our > application. > > The deviation was measured by toggling a GPIO pin at each timer.fired > event: > > event void Timer0.fired() { > call Leds.led0Toggle(); > } > > and measuring the resulting signal via a scope. The behaviour happens > with the > default TinyOS implementation of atm128rfa1 (tos/chips/atm128rfa1/timer) > on > multiple platforms among them the ucmini. All show the same offset. In > contrast > the same test with atmega1281-module result error <0.01s per 10s. > > Do you have any idea what might cause this behaviour? > > Best regards, > Elena > > > _______________________________________________ > Tinyos-help mailing list > Tinyos-help@millennium.berkeley.edu > <mailto:Tinyos-help@millennium.berkeley.edu> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > <https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help> > > -- Dipl.-Ing. Elena Chervakova Embedded Software Development System Design IMMS Institut für Mikroelektronik- und Mechatronik-Systeme gemeinnützige GmbH Ehrenbergstraße 27 D–98693 Ilmenau Achtung – das IMMS Ilmenau hat neue Telefonnummern: Tel.: +49.3677.87493.58 Fax: +49.3677.87493.15 E-Mail: elena.chervak...@imms.de Internet: http://www.imms.de Geschäftsführer: Prof. Dr. Ralf Sommer - Dipl.-Ing. Hans-Joachim Kelm Aufsichtsratsvorsitzender: Robert Fetter Sitz: Ilmenau - Rechtsform: Gesellschaft mit beschränkter Haftung Registergericht: Amtsgericht Jena HRB 303807 Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Mail sind nicht gestattet. This e-mail contains confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden. _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
