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by JohnBeardmore
Fri Aug 16, 2019 5:35 pm
Forum: Troubleshooting
Topic: GPIO only has current at 5V pins (none at 3.3V pins)
Replies: 21
Views: 2150

Re: GPIO only has current at 5V pins (none at 3.3V pins)

Don't think any of my failed Pis were abused or had their 3V3 rails shorted. Most were in IP65 boxes in a chicken shed measurig air quality, not on the work bench having uninsulated DMM probes poked at the pins. The only other one was in a similarly protective box in a nice warm chemistry lab sniffi...
by JohnBeardmore
Fri Aug 16, 2019 2:50 pm
Forum: Troubleshooting
Topic: GPIO only has current at 5V pins (none at 3.3V pins)
Replies: 21
Views: 2150

Re: GPIO only has current at 5V pins (none at 3.3V pins)

So to ask the obvious question again,

"Has this issue been overcome in the Pi4 ?".

If not, I'm still sticking with the nonplussed Pi3B if I can still get them.


Cheers, J/.
by JohnBeardmore
Fri Jan 11, 2019 12:54 am
Forum: Troubleshooting
Topic: GPIO only has current at 5V pins (none at 3.3V pins)
Replies: 21
Views: 2150

Re: GPIO only has current at 5V pins (none at 3.3V pins)

We bought a bunch of 3B+ boards back in early summer. We used 6 on a farm for logging air quality in chicken sheds, one as a data logger in the chemistry lab, and had a few spares. Of the 7 used, I'd guess four have been prone to inexplicable crashes on the farm sometimes with silly 3V3 rail voltage...
by JohnBeardmore
Sun Jan 06, 2019 12:52 am
Forum: General discussion
Topic: How to deal with the "logs filling up space" problem?
Replies: 19
Views: 27211

Re: How to deal with the "logs filling up space" problem?

Probably just me being stupid, but I've never been able to get

> syslog
> syslog.1
> kern.log
> kern.log.1
etc

to work from a shell script, or from system() commands within a C++ program. Is there a way ?

Cheers, J/.
by JohnBeardmore
Sat Jan 05, 2019 11:53 pm
Forum: Troubleshooting
Topic: GPIO only has current at 5V pins (none at 3.3V pins)
Replies: 21
Views: 2150

Re: GPIO only has current at 5V pins (none at 3.3V pins)

So why have "some pi3B+ have suffered sudden failures in this way" ? This is interesting. We made a board of support hardware for our Pi projectcts (open hardware if anyone's interested), which has various 5V PSU options. These power the Pi, which in turn provides 3.3V power of a hardware watchdog t...
by JohnBeardmore
Tue Apr 17, 2018 12:21 am
Forum: Beginners
Topic: Unable to locate package xrdp
Replies: 9
Views: 7416

Re: Unable to locate package xrdp

Good to know there is a way to change the resolution in VNC. A shame it's not a little more obvious. Maybe it is if you know enough.

But I thihnk I'll stick with xrdp, not least because its said to work better over low bandwidth links, and some of our clients have very low bandwidth.

Cheers, J/.
by JohnBeardmore
Sun Apr 15, 2018 11:40 pm
Forum: Beginners
Topic: Unable to locate package xrdp
Replies: 9
Views: 7416

Re: Unable to locate package xrdp

OK, I'm going to answer my own question. Despite having run it no more than 20 minutes ago, I had to run 'apt-get update' again before apt would find and install it. Having installed it, the resolution is good as ever which blows away VNC, and I confirm that I didn't have to uninstall anything on St...
by JohnBeardmore
Sun Apr 15, 2018 11:32 pm
Forum: Beginners
Topic: Unable to locate package xrdp
Replies: 9
Views: 7416

Re: Unable to locate package xrdp

Given the resolution issues with VNC, did anybody find out why xrdp can't be located ?

Cheers J/.
by JohnBeardmore
Mon Apr 09, 2018 1:18 pm
Forum: General discussion
Topic: Raspbian Stretch Headless Setup Procedure
Replies: 69
Views: 243288

Re: Raspbian Stretch Headless Setup Procedure

Where do you put the wpa_supplicant.conf file when making a headless system ?

Thanks, J/.
by JohnBeardmore
Fri Jan 19, 2018 2:46 am
Forum: Bare metal, Assembly language
Topic: GPIO pull up resisance
Replies: 15
Views: 28117

Re: GPIO pull up resisance

Not to worry, we've all been there !

Cheers, J/.
by JohnBeardmore
Thu Jan 18, 2018 11:52 am
Forum: Bare metal, Assembly language
Topic: GPIO pull up resisance
Replies: 15
Views: 28117

Re: GPIO pull up resisance

Yes, this April 2013 discussion was back in the days of the original Pis. At the moment we use the Pi 3 for new systems in the 'field', the Pi 2 for most development, and the Pi 1 is still in use in our original systems, and is still usefully collecting data after more than five years. Pi 4 anyone ?...
by JohnBeardmore
Thu Jan 18, 2018 1:12 am
Forum: Bare metal, Assembly language
Topic: GPIO pull up resisance
Replies: 15
Views: 28117

Re: GPIO pull up resisance

JRA wrote: >People please. There's complete misinformation here. :| Well, let's see... >Please understand that an external pull-up or pull-down placed on a GPIO pin setup as an input draws >zero current from the Input. Doesn't matter what value of resistance. You can hard ground that pin or >tie it ...
by JohnBeardmore
Sat Jan 06, 2018 11:06 pm
Forum: General discussion
Topic: Destroyed components
Replies: 20
Views: 4569

Re: Destroyed components

Thanks !

Yes, we discovered that it worked. It's now hapily ensconced as a reseach project BMS thingy in Nottingham University.

Good news about the schematics by the way. I thought they hadn't released them post the original Pis.

Cheers, J/.
by JohnBeardmore
Fri Jan 05, 2018 9:43 pm
Forum: HATs and other add-ons
Topic: Gertboard with Pi2 Jessie
Replies: 7
Views: 3497

Re: Gertboard with Pi2 Jessie

Come to think of it, could BCM2708_PERI_BASE ... be set automatically somehow so that the Gertboard can sensibly be used with the Pi 2 and the P 3 ?

Cheers, J/.
by JohnBeardmore
Fri Jan 05, 2018 9:21 pm
Forum: HATs and other add-ons
Topic: Gertboard with Pi2 Jessie
Replies: 7
Views: 3497

Re: Gertboard with Pi2 Jessie

Hi Gert, I'm having problems getting the SPI DAC to work too. I don't suppose you want to share the code you wrote ? Re the change of BCM2708_PERI_BASE, it might be worth shouting that from the roof tops given that people are still using the Gertboard code as examples of how to do IO on the Pi ! Che...
by JohnBeardmore
Wed Nov 15, 2017 1:11 pm
Forum: General discussion
Topic: Destroyed components
Replies: 20
Views: 4569

Re: Destroyed components

Thanks folks, I'll have a poke around.

Cheers, J/.
by JohnBeardmore
Tue Nov 14, 2017 7:35 pm
Forum: General discussion
Topic: Destroyed components
Replies: 20
Views: 4569

Re: Destroyed components

Good thread sise, but not long enough. We have a lot of stuff under the Pi on our board, so I tend to use pillars that are long and have a big diameter to give mechanical stability.

Cheers, J/.
by JohnBeardmore
Mon Nov 13, 2017 9:13 pm
Forum: General discussion
Topic: Destroyed components
Replies: 20
Views: 4569

Re: Destroyed components

Yes you can, but the smallest I cn see is M3, and M3 screws won't go through the Pi board without a bit of a fight. If you know anyone who sells these things with M2.5 threads, please share, because it would be better. Failing that I think I'll stick to tapping the M3 pillars into the boards. Cheers...
by JohnBeardmore
Mon Nov 13, 2017 6:58 pm
Forum: General discussion
Topic: Destroyed components
Replies: 20
Views: 4569

Re: Destroyed components

I've only done damage this way once. Other options include having the nuts finger tight and putting a drop of thread lock or nail varnish on them to stop them coming undone. It's also worth noting that M3 screws will self tap into the holes on the Pi 2 and Pi 3. Nuts aren't really needed except for ...
by JohnBeardmore
Mon Nov 13, 2017 3:24 am
Forum: General discussion
Topic: Destroyed components
Replies: 20
Views: 4569

Re: Destroyed components

A nut driver won't fit in there. Long nose pliers will only turn it about 20 degrees at a time.

J/.
by JohnBeardmore
Sun Nov 12, 2017 11:39 pm
Forum: General discussion
Topic: Destroyed components
Replies: 20
Views: 4569

Re: Destroyed components

So did you manage to replace your C90 ? Did the system work without it ? I've just done the same as you. There has to be a better way to mount these things !

Many thanks, J/.
by JohnBeardmore
Sun Nov 12, 2017 11:35 pm
Forum: General discussion
Topic: Capacitors C90 rip out
Replies: 9
Views: 1368

Re: Capacitors C90 rip out

So did you manage to replace your C90 ? Did the system work without it ? I've just done the same as you. There has to be a better way to mount these things !

Cheers, J/.
by JohnBeardmore
Sun Nov 12, 2017 6:39 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: 5 Volt connections to Pi 3 board
Replies: 5
Views: 1482

Re: 5 Volt connections to Pi 3 board

Yes, in the end I soldered ontpo the back of the 40 pin header. Looked a bit fragile so I splodged a squirt from a hot glue gun on to it for strain relief. Looks OK provisionally (getting 5V on to the board and 3V3 off it), but haven't booted it yet. Waiting for an SD card with code compiled on it. ...
by JohnBeardmore
Fri Nov 10, 2017 7:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: 5 Volt connections to Pi 3 board
Replies: 5
Views: 1482

Re: 5 Volt connections to Pi 3 board

It looks as if the pin next to 'Run' is a grond too.

Cheers, J/.
by JohnBeardmore
Tue Nov 07, 2017 11:35 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: EnOcean Pi board serial interface
Replies: 0
Views: 404

EnOcean Pi board serial interface

Has anybody successfully written their own code to access the EnoceanPi board through the serial interface on the Pi 3 ?

If so, what device name did you open, and what serial parameters (baud rate etc) did you need to use ?

Many thanks, J/.

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