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by rpdom
Wed Sep 20, 2017 8:38 am
Forum: Beginners
Topic: Service to Safe Shutdown Headless Raspberry Pi Boards
Replies: 8
Views: 211

Re: Service to Safe Shutdown Headless Raspberry Pi Boards

Yes I did. It worked perfectly. I'm betting you didn't test it running on a USB drive. An rpi-update is required. No. I didn't. The OP didn't specify a USB drive, so I didn't see the point. I don't have time to test with a USB drive right now, and am not sure why you brought up the subject. Now I h...
by rpdom
Wed Sep 20, 2017 6:09 am
Forum: Beginners
Topic: Service to Safe Shutdown Headless Raspberry Pi Boards
Replies: 8
Views: 211

Re: Service to Safe Shutdown Headless Raspberry Pi Boards

RonR wrote:
Wed Sep 20, 2017 6:05 am
rpdom wrote:
Wed Sep 20, 2017 5:32 am
Yes I did. It worked perfectly.
I'm betting you didn't test it running on a USB drive. An rpi-update is required.
No. I didn't. The OP didn't specify a USB drive, so I didn't see the point.

I don't have time to test with a USB drive right now, and am not sure why you brought up the subject.
by rpdom
Wed Sep 20, 2017 6:07 am
Forum: Bare metal
Topic: Why is toggling GPIO pins not a race condition?
Replies: 4
Views: 145

Re: Why is toggling GPIO pins not a race condition?

The bits are not in memory. They are direct hardware locations that are mapped into memory space. They are just triggers. They are connected to the set and reset parts of the GPIO drivers, so writing a bit takes effect pretty immediately. You can write one at a time or all together it doesn't matter...
by rpdom
Wed Sep 20, 2017 5:51 am
Forum: General discussion
Topic: Need help on precise RPM calculation regarding a car's tire size on a road
Replies: 29
Views: 665

Re: Need help on precise RPM calculation regarding a car's tire size on a road

Imperf3kt wrote:
Tue Sep 19, 2017 9:44 pm
An error of 10000mm, aka 1 meter.
10000mm is 1000cm is 10m
by rpdom
Wed Sep 20, 2017 5:32 am
Forum: Beginners
Topic: Service to Safe Shutdown Headless Raspberry Pi Boards
Replies: 8
Views: 211

Re: Service to Safe Shutdown Headless Raspberry Pi Boards

2. Run rpi-update .... FTFY :D You obviously didn't do any testing before posting. The firmware and/or kernel included in the latest Stretch image has to be updated for this feature to function properly. Yes I did. It worked perfectly. Do not run rpi-update unless one of the Foundation experts tell...
by rpdom
Wed Sep 20, 2017 4:46 am
Forum: Beginners
Topic: Service to Safe Shutdown Headless Raspberry Pi Boards
Replies: 8
Views: 211

Re: Service to Safe Shutdown Headless Raspberry Pi Boards

The capability to shutdown and restart a Raspberry Pi using a normally open momentary pushbutton switch connected to GPIO pins 5 & 6 is already present in Raspbian Stretch and requires no additional software. To enable it: 1. Add the following line to /boot/config.txt: dtoverlay=gpio-shutdown 2. Ru...
by rpdom
Tue Sep 19, 2017 7:53 pm
Forum: Troubleshooting
Topic: Cannot Install Pigpio
Replies: 6
Views: 105

Re: Cannot Install Pigpio

That didn't download correctly then. I suspect you have got an error message instead of the contents.

Try file pigpio.zip to identify the contents. It may say something like "blah text", in which case cat pigpio.zip to see what the text says.
by rpdom
Tue Sep 19, 2017 7:22 pm
Forum: General discussion
Topic: Need help on precise RPM calculation regarding a car's tire size on a road
Replies: 29
Views: 665

Re: Need help on precise RPM calculation regarding a car's tire size on a road

1) Every point around the tyre tread is connected to a point on the rim. Assuming there is no slippage of the tire around the rim that point to point mapping never changes. The tread is not a solid thing though. There are gaps in it (unless running slicks). The tread has the ability to flex in and ...
by rpdom
Tue Sep 19, 2017 7:09 pm
Forum: Troubleshooting
Topic: Cannot Install Pigpio
Replies: 6
Views: 105

Re: Cannot Install Pigpio

What size is the downloaded .zip file? I just tried it and it worked. The file size is 360018 bytes.
by rpdom
Mon Sep 18, 2017 8:16 pm
Forum: Advanced users
Topic: RaspiZero breaks and restarts only after SD is read with Mac
Replies: 8
Views: 195

Re: RaspiZero breaks and restarts only after SD is read with Mac

If you must call a script that never ends from rc.local, at least put it in the background with an & on the end of the command, otherwise you will get a system that gets stuck at boot time while it waits for the endless script to finish
by rpdom
Mon Sep 18, 2017 8:09 pm
Forum: Camera board
Topic: pi zero camera board adapter
Replies: 5
Views: 130

Re: pi zero camera board adapter

Have you got the cables in the right way up? I'm not sure as I use the cables that come with the Pi Zero cases, but think the contact side of the cables should be facing downwards towards the boards.

Those adaptors will definitely work with the standard cameras and a Pi Zero.
by rpdom
Mon Sep 18, 2017 2:38 pm
Forum: General discussion
Topic: Where is GPIO01?
Replies: 3
Views: 122

Re: Where is GPIO01?

If you are following a tutorial, could you give us a link to it, as there are a number of different naming conventions for the pins.
by rpdom
Mon Sep 18, 2017 2:18 pm
Forum: Beginners
Topic: how to install GPIO on Zero
Replies: 4
Views: 126

Re: how to install GPIO on Zero

The tutorial is a bit misleading. It is mixing up two packages: wiringpi and raspi-gpio. Wiring Pi has the gpio command and can be installed with sudo apt-get install wiringpi

pcmanbob has already pointed out the other one.
by rpdom
Mon Sep 18, 2017 2:15 pm
Forum: General discussion
Topic: SSH Putty doesn't work (RPi Zero W)
Replies: 11
Views: 782

Re: SSH Putty doesn't work (RPi Zero W)

Some routers prevent local access to and from wifi devices. Presumably this is for extra security - if someone cracks your wifi access they may be able to steal your bandwidth but they can't get at your PC... Disabling that option may allow you to connect to your Pi with wifi. It is called something...
by rpdom
Mon Sep 18, 2017 6:12 am
Forum: Advanced users
Topic: Turning on and off HDMI output based on GPIO settings - Trouble with XAuthority and python script.
Replies: 3
Views: 128

Re: Turning on and off HDMI output based on GPIO settings - Trouble with XAuthority and python script.

beta-tester wrote:
Sun Sep 17, 2017 9:40 pm
isn't it possible to "sudo" only the parts that needs to be running with root permissions from the script?
instead of running the whole script as root, run only "tvservice..." as root.
tvservice doesn't need to be run as root. Neither should the gpio access now.
by rpdom
Mon Sep 18, 2017 5:48 am
Forum: Automation, sensing and robotics
Topic: Solution for water pump control, RPi suitable?
Replies: 5
Views: 223

Re: Solution for water pump control, RPi suitable?

If the pumps stop then we won't have any water but it is water used for watering home-gardening, lawns and filling an occasional pool or two so no one is fully dependent on the water. Communal water here in Sweden is not expensive but it is considered a "waste of drinking water" to water your lawn ...
by rpdom
Mon Sep 18, 2017 5:31 am
Forum: Troubleshooting
Topic: LIRC not working on Raspbian Stretch Raspberry Pi
Replies: 7
Views: 345

Re: LIRC not working on Raspbian Stretch Raspberry Pi

EitanR wrote:
Sun Sep 17, 2017 10:51 pm
Where can I find the Jessie image?
I can only see jessie as ISO file.
https://www.raspberrypi.org/downloads/raspbian/ has the image files for the Raspberry Pi, both Lite and full Desktop version.
The ISO file is for PCs.
by rpdom
Mon Sep 18, 2017 5:27 am
Forum: Other projects
Topic: Send XML document via QR code
Replies: 2
Views: 99

Re: Send XML document via QR code

How big is your XML document? XML doc will be not so big, for examlpe 20 lines. 20 lines should be under 4K, unless they are very long lines (200+ characters). The alternative is to encode a URI where the XML can be downloaded from. Encoding (less than 4K) into a QR is trivial with https://packages...
by rpdom
Mon Sep 18, 2017 5:03 am
Forum: Troubleshooting
Topic: Network Interface Issue - DHCP
Replies: 56
Views: 806

Re: Network Interface Issue - DHCP

In the latest Stretch version the exxxxxxx format for interface names have been disabled and you get the old eth0 interface again.
by rpdom
Sat Sep 16, 2017 8:12 am
Forum: Troubleshooting
Topic: CRON scheduler runs - but nothing happens
Replies: 20
Views: 455

Re: CRON scheduler runs - but nothing happens

Regarding the "modprobe not found" errors, perhaps you should put the full path to the modprobe command in your script: /sbin/modprobe, although I'm not sure why you are using that. Can you post the contents of the script? [edit] Ah, you have already done that. These lines ##Setting up connection to...
by rpdom
Sat Sep 16, 2017 7:12 am
Forum: Compute Module
Topic: Connection Lan 9514 and Computer Module V3
Replies: 4
Views: 182

Re: Connection Lan 9514 and Computer Module V3

If you mean that you have to have the LAN9514's USB connected to the CM, and USB running on the CM, well yes, the ethernet on the LAN9514 runs from USB. The chip is basically a 5-port USB hub with an internal USB ethernet adaptor using one of those 5 ports. If that's not what you mean, could you cla...
by rpdom
Fri Sep 15, 2017 7:10 pm
Forum: Scratch
Topic: Itchy problem :)
Replies: 5
Views: 174

Re: Itchy problem :)

B.Goode wrote:
Fri Sep 15, 2017 6:37 pm
Failing that: does Scratch2 actually run on old/original RPi hardware or does it need one of the later CPU chips?
I believe the Scratch 2 for the Pi needs a Pi 2 or above.
by rpdom
Fri Sep 15, 2017 6:59 pm
Forum: Compute Module
Topic: I2C0 on CM3
Replies: 4
Views: 129

Re: I2C0 on CM3

For the A+ I would look at https://pinout.xyz

I2C0 SDA is GPIO 0 on pin 27 (ID_SD) and I2C0 SCL is GPIO 1 on pin 28 (ID_SC)
by rpdom
Fri Sep 15, 2017 6:50 pm
Forum: General programming discussion
Topic: C or C++ ?
Replies: 17
Views: 461

Re: C or C++ ?

Use whichever you are most comfortable with. C libraries can be used with C++ without a lot of work.
by rpdom
Fri Sep 15, 2017 6:20 pm
Forum: C/C++
Topic: First c program write in raspberry pi.
Replies: 54
Views: 33760

Re: First c program write in raspberry pi.

Where do I look up command line instructions? Usually from the command line you can use the "man" command to get the manual for most commands. So to find out what options are available for cc (or gcc) - warning: there are a lot of them - use man cc Or go to one of the online manpage websites where ...

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