It is there to detect if the 3.3V regulator, that is separate from the PMIC, is working. he shunt resistor was removed from the BeagleBone Black design. I felt that detecting the regulator was more important than a feature very few people used.
Gerald On Mon, Dec 16, 2013 at 3:16 PM, <[email protected]> wrote: > Hi Gerald, > > Could you explain why you decided to remove this from the BeagleBone > Black? I cannot figure out the use of AIN7 in the BeagleBone Black > configuration. > > I understand its use in the BeagleBone. However in the BeagleBone Black, > it seems to me that it should read a fixed value of 1.65V. Am I missing > something? > > I read in a couple of places that it could still be used to measure the > power consumption by adding a shunt resistor. From looking at the schematic > of the BeagleBone Black I do not see how this is possible. Do you have any > hint on this? > > Thanks in advance, > Nicolas > > > On Monday, August 12, 2013 8:39:50 PM UTC-4, Gerald wrote: > >> There is not. LiION batteries typically use fuel gauges as you cannot >> rely on voltage as an indicator of capacity. I removed this from the >> design. The BeagleBone has this feature and I am familiar with its >> function.. >> >> I have no plans to add it back in to the BBB. >> >> >> Gerald >> >> >> >> On Mon, Aug 12, 2013 at 6:22 PM, chameleon452 <[email protected]> wrote: >> >>> Hello, >>> >>> I have a BB black and was wondering if there is a way to read the >>> voltages for the power supplies, in particular the battery, in order to >>> implement a battery level indicator. >>> >>> It appears that the PMIC (TPS65217C) provides an easy way to feed the >>> various supply voltages into an ADC pin, even properly scaled to 1.8V, >>> through the MUX_OUT pin. I can read and write the various PMIC statuses >>> through /dev/i2c-0, but unfortunately according to the BB schematic the >>> MUX_OUT pin doesn't appear to be connected to anything, so it looks like >>> it's impossible to sample the voltages. >>> >>> Is there another way to read the battery level that I am missing? If >>> not, it might be a good idea for future revisions to connect the PMIC's >>> MUX_OUT to one of the AM335x's ADCs. This shouldn't create any >>> incompatibilities as the default setting for the MUX is high impedance (see >>> MUXCTRL in the TPS65217 reference manual, http://www.ti.com/lit/ >>> ds/symlink/tps65217c.pdf). >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >>> >>> >> >> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
