We have been doing experiments with power measurements. What I do is power through the battery connector unless programming. To program, disconnect the battery power and hook it up to the usb. It can get a little tiresome. We removed the battery holder and simply connected wires to a bench power supply instead. No reason to modify past that. It's a lot faster to turn the bench supply off than it would be to remove batteries.
We also did experiments measuring current using the USB power. We interrupted the usb ground line and put a 3 ohm resistor in it and measured the voltage across the resistor. The only problem is that the usb chip takes a lot of power and it's a leap of imagination to try to subtract that out of the power calculations. We redid the experiments without the USB chip, and it was more work but also more satisfying. On Fri, Jan 9, 2009 at 2:34 PM, Jimmy <[email protected]> wrote: > Hi, > > I am looking for some help regarding the TMote Sky motes. > > My problem: I want to simulate the draining battery using external > circuitry (i.e. using a programmable power supply), but to do that the > USB power must be cut-off and still need to communicate with the host > computer. So, I disconnected the 5V power line from the USB cable, and > when I do that the host computer cannot be able to see the Tmote > connected to its USB and hence not able to program it. > > I also tried to program the TMote Sky when it is getting power from > 2-AA batteries and USB power cut-off, and the result is that the host > computer cannot see the TMote Sky. > > Is there a way to program the TMote Sky with USB connected and without > using USB power (5V). > > Please help me on this regard. Sentilla has discontinued support for > the Tmote Sky (http://www.sentilla.com/moteiv-transition.html). > > Thank you, > Jimmy > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
