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MSP-EXP430FR5739: Current draw too high - are there benchmark currents for example projects?

David Bleloch
Prodigy 80 points
Part Number: MSP-EXP430FR5739
Other Parts Discussed in Thread: ENERGYTRACE,

Hi,

I have been writing code for a new product using the part above.  Functionally, the device is fine, but my code, which spends almost all of its time in a LPM4, is causing current draw of 2.4mA.  This far too high, and can't be right.  I've tried many example projects and they all take a large current like this.

I have also been unable to use EnergyTrace due to an error message "error communicating with FET USB1".  All of the jumpers on the board are present, but the current doesn't change much whether they are there or not.

Do you have any "expected" currents for the particular example projects available for this board (so that I can test them) or could you test them for me please?

I am using a Keysight 34450A on 100mA range across the VCC jumper.

Can you tell me why the EnergyTrace doesn't work for me.. I've tried changing settings but nothing seems to work?

thank you

David

  • 0
    Guru 88720 points

    According to "MSP Debuggers" (SLAU647O) Table 1, the MSP-EXP430FR5739 doesn't support (any form of) EnergyTrace.

    Be sure to remove any unneeded jumpers, in particular TXD/RXD on J3 ("bridge") . You probably need MSP_PWR, but not RF_PWR. Also make sure (in the code) that P2OUT.7=0 since it powers the accelerometer.

    You didn't mention any specific Examples, but some LPM examples set all the pins as outputs, which can result in bus conflicts with whatever "extras" the particular Launchpad provides.

  • 0 in reply to Bruce McKenney47378
    Guru 88720 points

    I just tried example msp430fr57xx_lpm4.c:

    https://dev.ti.com/tirex/explore/node?node=AGa.SjW1EMaQNOfDToQg9Q__IOGqZri__LATEST

    Removing the TXD/RXD jumpers dropped consumption from 335uA to 7uA [Fluke 79-III measured across J3-VCC].

    [Edit: Also Tools->EnergyTrace was greyed-out, which fits with Table 1]

  • 0 in reply to Bruce McKenney47378
    Prodigy 80 points

    Many thanks Bruce.  You're quite right, I went through all the sensible things, looking through the schem to see if there's any give-aways (the PIC dev board had a potentiometer straight across the MCU rail on their dev board for testing the analogue inputs!.  I've driven P2.7 low and the same with the other two lines attached to the accel.  I hate blaming the kit, but I just needed a known project or binary to test my board with to make sure there isn't some kind of fault with it.  I'll try the one in your next post in a minute.

  • 0 in reply to Bruce McKenney47378
    Prodigy 80 points

    Bruce you're a star.  That's exactly what I needed.  ~322µA (jumpers in place) and 6µA (jumpers removed) on my dev board, using stock compiler settings for that project.  There's no problem with the board.. just the engineer!.. I now have somewhere to start from.  Many thanks.

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