Re: [beagleboard] Pocket Beagle power question

[Graham Haddock]

What I would do is some minor surgery on the PocketBeagle, disconnecting
the +5V lead coming in the microUSB connector.
The easiest way to do this would be to remove FB1 (ferrite bead in series
with USB +5).
Easy with "hot tweezers", or a pair of small soldering irons.
To restore the Pocketbeagle to factory configuration, solder FB1 back in.

Short P1-Pin-1 and P1-Pin-7 together, and power the Beagle from whatever
you are going to power it with at +5V.
No issues with instability.

Now you can plug in USB for programming and anything else you want/need to
do, at any time. It just won't take power through the USB cable any more.

--- Graham

==


On Sat, Aug 10, 2019 at 12:18 AM Jim F  wrote:

> Ahhh. I've had some of this pain. I did actually raise xmodem from the
> dead, but had enough problems that I just got a secondary USB port working
> and put a wifi dingle on it. Anyway what you want to do, sounds like it
> will work.
>
> On Fri, Aug 9, 2019, 9:07 PM Robert Heller  wrote:
>
>> At Fri, 9 Aug 2019 17:01:28 -0400 beagleboard@googlegroups.com wrote:
>>
>> >
>> >
>> > Robert,
>> >
>> > If you have a look at the Pocketbeagle schematic, you can see what
>> happens
>> > with the USB connector, which comes in on page 2. Power on that pin
>> goes to
>> > VIN.USB, which goes straight to (page 3) the Octavo OSD3358 VIN_USB
>> pins.
>> >
>> > You can look at the Octavo datasheet [1] - it's for the OSD335x_SM -
>> they
>> > tell you almost nothing. The only partly useful thing they tell you is
>> "The
>> > OSD335x-SM may be powered by any combination of the following input
>> power
>> > supplies. Please refer to the TPS65217C datasheet for details." The
>> > smartest thing to do would be to map the pins to the chips they are
>> > connected to using Octavo's tool [2] and the TI datasheets. I'm certain
>> > there's no isolation, but there is a switch to enable one or the other
>> > inputs (perhaps you had a looser definition of isolation in mind).
>> Figure
>> > 11 on page 27 of the TPS65217C datasheet [3] should show you what that
>> > looks like. These are configured by the PPATH register in [3], which I
>> am
>> > not precisely certain how it is configured in the first place, but you
>> > should be able to modify it on I2C0 (I think).
>> >
>> > All that said, it looks to me like it's fine to do. But I feel like I've
>> > done this and had some weird results, I just can't remember exactly what
>> > they were. I think the results included unplanned reverse power flow
>> (USB
>> > charging other things connected to the same VIN power supply), the
>> device
>> > not shutting down exactly as I expected, and similar behavior. I don't
>> > think we smoked anything, though, so there's that. Worth looking through
>> > that data sheet a little to make sure you're happy first.
>>
>> OK.  The reason I want to know is that I have an expansion board that
>> supplies
>> power (and does other things).  It does have a serial console header, so
>> I can
>> connect a TTL serial<=> USB cable for debugging, but unless I really want
>> to
>> raise XModem (from the dead?) there isn't any way to do something like
>> download a fresh executable program ("cross" built on a RPi).  I just
>> wondered
>> if it is "safest" to just unplug the Pocket Beagle from the expansion
>> board
>> and tether it to my laptop and use the Tcp/Ip over USB to do the "large"
>> transfers of things like exe files, etc.  This is what I have been doing
>> and
>> was wondering if I really have to do it that way or if I can plug in the
>> USB
>> while the Pocket Beagle is still being powered by the expansion board.
>>
>> >
>> > I would be quite interested to know precisely where PPATH is configured,
>> > beyond its default settings. It may be in the uboot source which is not
>> [I
>> > think] in the BB distributions. That stuff isn't bad to look at, and I
>> was
>> > going to, but for the life of me I can't remember where I built that
>> and I
>> > can't find it right now. Robert also has a few scripts in
>> /opt/scripts/boot
>> > which configure a LOT of things, I've only scratched the surface trying
>> to
>> > understand them.
>> >
>> > [0] -
>> >
>> https://github.com/beagleboard/pocketbeagle/blob/master/PocketBeagle_sch.pdf
>> > [1] - https://octavosystems.com/docs/osd335x-sm-datasheet/
>> > [2] -
>> https://octavosystems.com/app_notes/osd335x-family-pin-assignments/
>> > (search for VIN_USB)
>> > [3] - http://www.ti.com/lit/ds/symlink/tps65217.pdf
>> >
>> > Hope that helps. I have nothing to do with the pocket beagle but I did
>> spin
>> > a couple boards based on it and the octavo RED board.
>> >
>> > Best,
>> >
>> > Jim
>> >
>> > On Fri, Aug 9, 2019 at 3:33 PM Robert Heller 
>> wrote:
>> >
>> > > If I am applying a 5V power supply to the Vin pin (P1-1) of a Pocket
>> Beagle
>> > > (say from an expansion board that includes a power supply), is it
>> safe to
>> > > also
>> > > plug in a [powered] micro-USB cable? That is, does the Pocket Beagle
>> have a
>> > 

Re: [beagleboard] How to execute >sudo sh -c "echo BB-SPIDEV0 > $SLOTS" from bash?

[Ram Kanhirotentavida]

Hi,

Please ignore my support request. I could resolve it by keeping the env
variable after sudo su.

Regards,
Ram

On Sat, Aug 10, 2019 at 1:30 AM Ram Kanhirotentavida 
wrote:

> Hi,
>
> I am setting up SPI0 for read and write from an ADC. To start I tried the
> loopback spidev_test found in chp08. This test is not working. When
> debugged found that the device overlay step is not running as expected.
>
> Details:
> .profile is set to run in bash shell with exporting SLOTS variable.
>
> export SLOTS=/sys/devices/platform/bone_capemgr/slots
>
> root@beaglebone:/lib/firmware# source ~/.profile
> root@beaglebone:/lib/firmware# sudo cat $SLOTS
>  0: PF  -1
>  1: PF  -1
>  2: PF  -1
>  3: PF  -1
>  4: P-O-L-   0 Override Board Name,00A0,Override Manuf,cape-universaln
> root@beaglebone:/lib/firmware#
>
> Above shows the BB-SPIDEV0 is missing hence run the below step. It
> generates sh: echo: I/O error
> >sudo sh -c "echo BB-SPIDEV0 > $SLOTS"
>
> How can I set the SPIDEV0 overlay to use SPI0?
>
> SPI loopback result shows 0's. Suppose to match the TX buffer.
>
> root@beaglebone:~/exploringBB/chp08/spi/spidev_test# ./spidev_test
> spi mode: 0
> bits per word: 8
> max speed: 50 Hz (500 KHz)
> Debug message: Return value = 38
>
> 00 00 00 00 00 00
> 00 00 00 00 00 00
> 00 00 00 00 00 00
> 00 00 00 00 00 00
> 00 00 00 00 00 00
> 00 00 00 00 00 00
> 00 00
>
> OS Details:
> >uname -a
> Linux beaglebone 4.1.15-ti-rt-r43 #1 SMP PREEMPT RT Thu Jan 21 20:13:58
> UTC 2016 armv7l GNU/Linux
>
> >cat /etc/dogtag
> BeagleBoard.org Debian Image 2016-01-24
>
> >cat /etc/debian_version
> 8.3
>
>
> Appreciate if you can help to resolve the issue.
>
> Thanks,
> Ram
>
> --
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> 
> .
>

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[beagleboard] How to execute >sudo sh -c "echo BB-SPIDEV0 > $SLOTS" from bash?

[Ram Kanhirotentavida]

Hi,

I am setting up SPI0 for read and write from an ADC. To start I tried the 
loopback spidev_test found in chp08. This test is not working. When 
debugged found that the device overlay step is not running as expected.

Details:
.profile is set to run in bash shell with exporting SLOTS variable.

export SLOTS=/sys/devices/platform/bone_capemgr/slots

root@beaglebone:/lib/firmware# source ~/.profile
root@beaglebone:/lib/firmware# sudo cat $SLOTS
 0: PF  -1
 1: PF  -1
 2: PF  -1
 3: PF  -1
 4: P-O-L-   0 Override Board Name,00A0,Override Manuf,cape-universaln
root@beaglebone:/lib/firmware#

Above shows the BB-SPIDEV0 is missing hence run the below step. It 
generates sh: echo: I/O error
>sudo sh -c "echo BB-SPIDEV0 > $SLOTS"

How can I set the SPIDEV0 overlay to use SPI0?

SPI loopback result shows 0's. Suppose to match the TX buffer.

root@beaglebone:~/exploringBB/chp08/spi/spidev_test# ./spidev_test
spi mode: 0
bits per word: 8
max speed: 50 Hz (500 KHz)
Debug message: Return value = 38

00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00 00 00 00 00
00 00

OS Details:
>uname -a
Linux beaglebone 4.1.15-ti-rt-r43 #1 SMP PREEMPT RT Thu Jan 21 20:13:58 UTC 
2016 armv7l GNU/Linux

>cat /etc/dogtag
BeagleBoard.org Debian Image 2016-01-24

>cat /etc/debian_version
8.3


Appreciate if you can help to resolve the issue.

Thanks,
Ram

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