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by DougieLawson
Thu Jan 24, 2019 7:25 am
Forum: General discussion
Topic: Can I power a Pi 3 B+ from the monitor USB A jack?
Replies: 2
Views: 36

Re: Can I power a Pi 3 B+ from the monitor USB A jack?

That's because back powering connects on the wrong side of the protection circuitry.

Don't do it, it's not a supported way of powering any of the 2B and later Raspberries.
by DougieLawson
Thu Jan 24, 2019 7:21 am
Forum: Other programming languages
Topic: Raspberry Pi MySQL Remote Connection (error: 10061)
Replies: 4
Views: 211

Re: Raspberry Pi MySQL Remote Connection (error: 10061)

Have you changed bind-address in mysql.cnf to 0.0.0.0?
by DougieLawson
Thu Jan 24, 2019 7:20 am
Forum: Advanced users
Topic: Chromium-Browser does not work from crontab -e
Replies: 5
Views: 105

Re: Chromium-Browser does not work from crontab -e

Faruk wrote:
Thu Jan 24, 2019 4:50 am
So how to control every hour from autostart file. Should the control mechanism be in the sh file?
You can't do it from cron. One possible way may be with https://docs.python.org/3/library/sched.html
by DougieLawson
Thu Jan 24, 2019 7:17 am
Forum: Troubleshooting
Topic: Putty Fatal Error on Reboot
Replies: 5
Views: 76

Re: Putty Fatal Error on Reboot

If you change something and on a reboot it reverts to the old value it means your SDCard is end-of-life and has gone into read-only mode.
by DougieLawson
Wed Jan 23, 2019 11:38 pm
Forum: Troubleshooting
Topic: I think I burned my Pi [3B+]
Replies: 15
Views: 267

Re: I think I burned my Pi [3B+]

PS: I connected the fan with Pi on (I should't have done this :( ) The ONLY things you can connect with the power on are HDMI and USB devices. (Although connecting a HDMI device after boot-up is a pain in the tail, you don't half have to muck about with the tvservice command to set the right mode)....
by DougieLawson
Wed Jan 23, 2019 10:46 pm
Forum: General programming discussion
Topic: On GPIO turn off power pins?
Replies: 4
Views: 11370

Re: On GPIO turn off power pins?

gabrielbalan wrote:
Wed Jan 23, 2019 10:06 pm
Please elaborate. I have the same problem :)
You'll have a long wait. François hasn't visited the forum for FOUR years.

Start a new thread, describe your hardware, describe your problem in detail. Don't bump ancient historical threads.
by DougieLawson
Wed Jan 23, 2019 8:47 pm
Forum: Other projects
Topic: Magi mining
Replies: 1
Views: 30

Re: Magi mining

It's not possible and not useful. You have heterogenous processor architectures (ARM on Pi, Intel X86 on your laptop), no way to access/share the same hardware (hard disks etc.) and a slow ethernet/USB connection on the RPi
by DougieLawson
Wed Jan 23, 2019 8:43 pm
Forum: Troubleshooting
Topic: Oops - unable to determine board type... model:14
Replies: 6
Views: 181

Re: Oops - unable to determine board type... model:14

MWW1977 wrote:
Wed Jan 23, 2019 8:39 pm
in what file should I change this?
The diff for each file that changes starts with +++ followed by the file name.
You can feed that into the patch command. It was created with diff -u.

Go and read the fine man pages.
https://linuxacademy.com/blog/linux/int ... and-patch/
by DougieLawson
Wed Jan 23, 2019 8:37 pm
Forum: Advanced users
Topic: Chromium-Browser does not work from crontab -e
Replies: 5
Views: 105

Re: Chromium-Browser does not work from crontab -e

You can't start GUI programs from cron.

Add a line item to /home/pi/.config/lxsession/LXDE-pi/autostart to get the browser started when the GUI comes up active.

Code: Select all

@lxpanel --profile LXDE-pi
@pcmanfm --desktop --profile LXDE-pi
@xscreensaver -no-splash
@point-rpi
@/bin/bash /home/pi/check.sh
by DougieLawson
Wed Jan 23, 2019 7:57 pm
Forum: Troubleshooting
Topic: Oops - unable to determine board type... model:14
Replies: 6
Views: 181

Re: Oops - unable to determine board type... model:14

Here's a diff with the changes needed for WiringPi 2.46: --- gpio/readall.c 2019-01-23 19:41:28.656773000 +0000 +++ ../wiringPi/gpio/readall.c 2019-01-23 19:50:36.666773000 +0000 @@ -307,6 +307,8 @@ printf (" +-----+-----+---------+------+---+---Pi 3---+---+------+---------+-----+-----+\n") ; else i...
by DougieLawson
Wed Jan 23, 2019 7:37 pm
Forum: C/C++
Topic: hardware pwm without wiringpi or other libraries
Replies: 1
Views: 55

Re: hardware pwm without wiringpi or other libraries

Have you looked at pigpio and pigpiod?
http://abyz.me.uk/rpi/pigpio/
by DougieLawson
Wed Jan 23, 2019 8:14 am
Forum: Troubleshooting
Topic: Can not detect IP on new Pi3 B+
Replies: 14
Views: 209

Re: Can not detect IP on new Pi3 B+

Your image is too old. Your 3B+ hasn't booted.

Try plain Raspbian 2018-11-13 then look at getting the Octopi stuff on that.
by DougieLawson
Wed Jan 23, 2019 12:34 am
Forum: Python
Topic: PiCamera script runs from IDE but not from terminal
Replies: 6
Views: 725

Re: PiCamera script runs from IDE but not from terminal

Why does that need sudo? Have you caught a nasty dose of sudoitis?
by DougieLawson
Tue Jan 22, 2019 11:52 pm
Forum: Troubleshooting
Topic: Oops - unable to determine board type... model:14
Replies: 6
Views: 181

Re: Oops - unable to determine board type... model:14

If you look at https://git.drogon.net/?p=wiringPi;a=commitdiff;h=8d188fa0e00bb8c6ff6eddd07bf92857e9bd533a it's relatively easy to see what changes were made for "PI_MODEL_3P 13". It wouldn't take long to replicate those lines for a PI_MODEL_3AP. It amounts to about five lines of code (including maki...
by DougieLawson
Tue Jan 22, 2019 10:43 pm
Forum: General discussion
Topic: Cannot boot from USB without SD card
Replies: 9
Views: 313

Re: Cannot boot from USB without SD card

Try Raspbian 2018-11-13 on your USB stick. That's guaranteed to work on a 3B (with the OTP bit set), on a 3B+ (straight out of the box) and on a 3A+ (same as 3B+). There are some late model 2Bs that can have the OTP set.
by DougieLawson
Tue Jan 22, 2019 10:30 pm
Forum: Troubleshooting
Topic: Stuck at booting shows this error
Replies: 4
Views: 132

Re: Stuck at booting shows this error

Your SDCard is unreadable. Get a factory fresh SDCard, write plain Raspbian 2018-11-13 to it using Etcher. Boot that new system. Mount the unreadable SDCard in a USB reader. Mount the USB reader in your RPi and see if you can undo the damage. So this is purely sdcard issue then ?? any specific sdca...
by DougieLawson
Mon Jan 21, 2019 10:07 pm
Forum: Camera board
Topic: RaspPi A+ Unable to Use Camera
Replies: 5
Views: 150

Re: RaspPi A+ Unable to Use Camera

I'm assuming you mean a 3A+ and not an orginal A+ from 2014.
How much gpu_mem is defined in /boot/config.txt?

For my RPi1B that has the camera I've got:

Code: Select all

gpu_mem=128
start_x=1
disable_camera_led=1
Is the ribbon cable connected the right way round?
by DougieLawson
Mon Jan 21, 2019 9:57 pm
Forum: Advanced users
Topic: How to Microsoft Remote Desktop via internet?
Replies: 2
Views: 99

Re: How to Microsoft Remote Desktop via internet?

Use RealVNC with the RealVNC Cloud support.
by DougieLawson
Mon Jan 21, 2019 8:56 pm
Forum: Beginners
Topic: What function would I use to do something every half second?
Replies: 6
Views: 109

Re: What function would I use to do something every half second?

I've done lots of useful (and accurate) timing in C++ with void wait3sec() { using std::chrono::system_clock; std::time_t tt = system_clock::to_time_t (system_clock::now()); struct std::tm *ptm = std::localtime(&tt); std::this_thread::sleep_for(std::chrono::seconds(3)); } Don't know what the limits ...
by DougieLawson
Mon Jan 21, 2019 8:45 pm
Forum: Automation, sensing and robotics
Topic: 2 LED wiring
Replies: 11
Views: 228

Re: 2 LED wiring

Try this: #!/usr/bin/python3 import time from gpiozero import LED led01 = LED(16) led02 = LED(20) while True: led01.on() print ("01") time.sleep(1) led01.off() led02.on() print ("02") time.sleep(1) led02.off() For Bob's wiring with a transistor try this: #!/usr/bin/python3 import time from gpiozero ...
by DougieLawson
Mon Jan 21, 2019 8:42 pm
Forum: Troubleshooting
Topic: Stuck at booting shows this error
Replies: 4
Views: 132

Re: Stuck at booting shows this error

Your SDCard is unreadable.

Get a factory fresh SDCard, write plain Raspbian 2018-11-13 to it using Etcher.
Boot that new system. Mount the unreadable SDCard in a USB reader. Mount the USB reader in your RPi and see if you can undo the damage.
by DougieLawson
Mon Jan 21, 2019 7:45 pm
Forum: General discussion
Topic: Features for future Pi, voltage/current reporting.
Replies: 49
Views: 977

Re: Features for future Pi, voltage/current reporting.

:lol: I was just trying to make a point so that people can see that it would be beneficial if it could be implemented for a low price. What possible use does it have? It's like reading the cpu temperature, what can you do if you don't like the numbers? If I know the power budget is limited I apply ...
by DougieLawson
Mon Jan 21, 2019 7:39 pm
Forum: Python
Topic: Learn Python 2 or 3 and how?
Replies: 15
Views: 330

Re: Learn Python 2 or 3 and how?

aamcle wrote:
Sun Jan 20, 2019 10:11 pm
1, Python 2.7 or Python 3?
For all new programs you should use python3 exclusively.

In eleven months, ten days, 4hours you won't get a choice.
https://pythonclock.org/

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