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Rafael Vega
Jan 29, 2015, 5:59:30 PM1/29/15
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Hi, I need to connect 12 potentiometers to the adc inputs in the BBB (through an analog multiplexer). I have found that if I use potentiometers with lower resistance values (2Kohm), the input is less noisy than if I use higher resistance pots (500KOhms). Since the pots are "powered" by VADC and AGND (1.8Volts), I need to know how much current I can draw from these two pins.
Anyone? :)
Rick Mann
Jan 29, 2015, 6:14:43 PM1/29/15
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I'm not sure. I read somewhere that the internal reference really should not supply current, but looking at the schematic, it looks like it's powered from the VDD_1V8 1.8 V rail, which can supply a total of 400 mA (according to the SRM). I don't know how much the rest of the system draws.
I have a 5K and 10K pot on mine, seems to work, but in the next version I will put a voltage follower on it.
> On Jan 29, 2015, at 14:59 , Rafael Vega <email...@gmail.com> wrote:
>
>
> Hi, I need to connect 12 potentiometers to the adc inputs in the BBB (through an analog multiplexer). I have found that if I use potentiometers with lower resistance values (2Kohm), the input is less noisy than if I use higher resistance pots (500KOhms). Since the pots are "powered" by VADC and AGND (1.8Volts), I need to know how much current I can draw from these two pins.
> Anyone? :)
>
> --
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Rick Mann
rm...@latencyzero.com
I have a 5K and 10K pot on mine, seems to work, but in the next version I will put a voltage follower on it.
> On Jan 29, 2015, at 14:59 , Rafael Vega <email...@gmail.com> wrote:
>
>
> Hi, I need to connect 12 potentiometers to the adc inputs in the BBB (through an analog multiplexer). I have found that if I use potentiometers with lower resistance values (2Kohm), the input is less noisy than if I use higher resistance pots (500KOhms). Since the pots are "powered" by VADC and AGND (1.8Volts), I need to know how much current I can draw from these two pins.
> Anyone? :)
>
> 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 beagleboard...@googlegroups.com.
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--
Rick Mann
rm...@latencyzero.com
evilwulfie
Jan 29, 2015, 7:26:04 PM1/29/15
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It is for reference only. if you need power, supply a regulator for that
purpose.
purpose.
evilwulfie
Jan 29, 2015, 7:28:44 PM1/29/15
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It is for reference only. if you need power, supply a regulator for that
purpose.
On 1/29/2015 3:14 PM, Rick Mann wrote:
purpose.
On 1/29/2015 3:14 PM, Rick Mann wrote:
Rafael Vega
Jan 30, 2015, 6:44:45 AM1/30/15
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Thanks!
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