1,2V is called a "float". On power up all GPIO pins are set to inputs.

Gerald


On Tue, Jun 2, 2015 at 8:33 AM, Ali Shahkar <[email protected]> wrote:

> I get about 1.2v when the BBB is powered on. This voltage is present on
> all GPIO pins!
>
> As mentioned earlier when the pin is set to OUTPUT and LOW I get 1.2v.
> However, when I set it to HIGH I get 3.3v. Subsequently, after setting it
> to HIGH, when I set it back to LOW the voltage drops to zero!
>
>
>
> On Jun 2, 2015, at 12:47 AM, Andrey Somov <[email protected]> wrote:
>
> If you connect a voltmeter what do you see ?
>
> Andrey
>
>
> On Monday, June 1, 2015 at 7:53:29 PM UTC+2, [email protected] wrote:
>>
>> I have been playing with the GPIO pins both through the OS as well as
>> Python using the adafruit libraries, and I am seeing some strange behavior.
>> When I connect an LED + 470 Ohm resistor to GND and a GPIO pin set as
>> OUTPUT, I see the LED glow dimly (i.e there is a slight voltage present)
>> even when the pin is set to LOW! When I set the pin to HIGH, however, I see
>> the expected result (i.e the LED lights up normally).
>>
>> This behavior is seen with all GPIOs, and I am wondering if it is normal.
>> Shouldn't the voltage across the GPIO pins and GND be zero when set to low?
>>
>> I have an Element 14 RevC. with the latest Debian installed.
>>
>> Any help/insight would be much appreciated.
>>
>>
>>
>>
>>  --
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-- 
Gerald

[email protected]
http://beagleboard.org/

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