Hello all,

I'm working on a research project involving power consumption in wireless sensor networks and have come across an interesting problem while trying to measure the current consumed by an ez430-RF2500.

I have an Agilent 34411 Digital Multimeter connected in series with the ez430-RF2500 target board. However, whenever I place the device into LPM3 and run timerA off of the VLO, the system behaves very erratically. Sometimes the system will power totally down and consume 150 uA and other times it will lock up and consume 5 mA. The same issue occurs with an Agilent 3458A DMM and I have test 4 different target boards with the same result.

If I remove the DMM from the system, the target board runs exactly as intended with no problem. All of the AppNotes from TI show current being measured with a series resistor and an oscilloscope. Is there anyone else that has seen this kind of problem? Is there any documentation from TI that anyone could point me to help explain this?

Thanks,

  Kenji Yamamoto, Northern Arizona University