I *SOLVED.* The problem was that eMMC was taking the gpio control while I'm using a SD card. I decommented this in /boot/uEnv.txt
dtb=am335x-bonegreen-overlay.dtb and now I get values on gpios! Thank you :) Il giorno martedì 14 febbraio 2017 02:14:05 UTC+1, Dennis Lee Bieber ha scritto: > > On Mon, 13 Feb 2017 07:36:31 -0800 (PST), Davide Aguiari > <[email protected] <javascript:>> declaimed the following: > > >I can confirm the sensor works with a Cortex M4 microcontroller (Udoo neo > >full) with an Arduino sketch with Adafruit Arduino library. > >Same wires, same jumpers. > > > Well, since you've verified the sensor works, that leaves checking > for > activity on the pin(s): oscilloscope, logic analyzer, etc. to see if the > wake up goes out, and if the sensor is sending a pulse train in response. > > Based on a datasheet for a DHT-11, the device uses active-low > logic. > That means there should be a pull-up resistor somewhere on the data pin > (as > I recall, these can be configured internal to the BBB when setting up the > pin mode). This can be checked with a DVM -- when the program is NOT > running, the data pin should show 3.3V IF there is a pull-up on it > (unfortunately, DVMs and VOMs are too slow to detect the wake-up -- when > the data line is set to 0V, nor the pulse train response [a VOM may > register a voltage between 0 and 3.3V during the response -- as it > "averages" the high and low periods]) > > While it won't read the device, you could use the DVM with the > sysfs > GPIO access to confirm you have the proper pin... P8_11 is "gpio45"; set > to > output, and then set to 1 or 0 and check the voltage for each. > > http://kilobaser.com/blog/2014-07-15-beaglebone-black-gpios > > -- > Wulfraed Dennis Lee Bieber AF6VN > [email protected] <javascript:> HTTP://wlfraed.home.netcom.com/ > > -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/332e6bfd-3acd-41ec-a097-7c27ee611dfd%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
