Current measurement on the beagleboard


The beagleboard has this cool resistor (R6, see page 38 of the HWRM)
that can be used to measure the current the board is using. Does the
TWL (or maybe even the OMAP3) have a spare ADC that can be connected
to it?
It would be really neat to have direct access to that information on
the beagle when testing various power modes.




People I know are interested in comparing how much power signal
processing tasks take in GPP vs DSP vs FPGA. Having a way to measure
this would be nice (beyond hooking a meter to the board).

The Lyrtech SFF SDR board has a way to measure the DSP/ARM current and
the FPGA current. I think the Xilinx guys wanted that feature :slight_smile: (The
problem with the Lyrtech SFF SDR board is the price point, so don't
bloat the beagle on my behalf)


The 3-channel ADC inputs to the TWL4030 are tied to ground on the
schematic at the end of the HW Reference Manual (page 120). These are
pins H4, J3 and G3.


If some one can list down what exactly can be done (with no major additional costs) to help/improve the Power Measurements then we can actually push this out in next rev of beagle boards.

May be we can add this as an issue to be tracked after concluding.


One option would be to bring out the 3 adc channels as pins (like the
test pads) so people can connect them to J2 if needed (you need two
channels since you can't tie one point of J2 to ground).