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by pfletch101
Mon Mar 30, 2020 2:45 pm
Forum: Troubleshooting
Topic: Linux autostart issue
Replies: 9
Views: 453

Re: Linux autostart issue

... systemd-analyze will tell you far more than you would ever want to know about this! :) The man pages are quite helpful, but you might want to start with systemd-analyze critical-path [your service name] The critical-path comand returns: pi@raspberrypi:~ $ systemd-analyze critical-path [GPS] Unk...
by pfletch101
Sat Mar 28, 2020 10:06 pm
Forum: Troubleshooting
Topic: Linux autostart issue
Replies: 9
Views: 453

Re: Linux autostart issue

Have you tried putting a sleep(60) (1 minute delay chosen arbitrarily) at the beginning of the script. If it runs solidly if you do that and everything works, you have solved your acute problem, and can find out exactly what is causing the trouble at your leisure. You say that it crashes when it tr...
by pfletch101
Sat Mar 28, 2020 6:57 pm
Forum: Troubleshooting
Topic: Linux autostart issue
Replies: 9
Views: 453

Re: Linux autostart issue

Still same problem with network-online.target. Have you tried putting a sleep(60) (1 minute delay chosen arbitrarily) at the beginning of the script. If it runs solidly if you do that and everything works, you have solved your acute problem, and can find out exactly what is causing the trouble at y...
by pfletch101
Sat Mar 28, 2020 4:46 pm
Forum: Troubleshooting
Topic: Linux autostart issue
Replies: 9
Views: 453

Re: Linux autostart issue

[Unit] Description=GPS Service After=network.target After=influxdb.service #After=influxdb [Service] Type=simple ExecStart=python3 /prog/GPS_main_V1.py Restart=on-failure [Install] WantedBy=multi-user.target You may want to try replacing your first 'After' with After=network-online.target 'network....
by pfletch101
Mon Mar 23, 2020 12:52 am
Forum: Beginners
Topic: GPU/CPU temperature limit for RPI3
Replies: 27
Views: 7584

Re: GPU/CPU temperature limit for RPI3

rpdom wrote:
Fri Mar 20, 2020 6:47 pm
It will slow down until the temperature drops to a safer level, then speed up again.
What if the ambient temperature is above the temperature that the control system regards as 'safer'?
by pfletch101
Mon Mar 23, 2020 12:35 am
Forum: General discussion
Topic: Set static IPv6 address on Raspbian Buster
Replies: 11
Views: 1379

Re: Set static IPv6 address on Raspbian Buster

Hello, how do I set a static IPv6 address on my Raspberry with Raspbian 10 Buster ? Thanks Others have answered your question, but you may be better advised to have your router assign the Pi a 'fixed' IP address. Assigning a networked device a fixed IP address 'locally' can lead to all sorts of pro...
by pfletch101
Thu Mar 19, 2020 7:54 pm
Forum: Networking and servers
Topic: Wireless temperature detection system
Replies: 2
Views: 258

Re: Wireless temperature detection system

Please place code within [ code][ /code] (omitting the spaces) tags, and ensure that indentation is maintained. Without this, your code is almost completely unreadable.
by pfletch101
Mon Mar 16, 2020 12:49 am
Forum: Beginners
Topic: Can a python script edit itself?
Replies: 2
Views: 303

Re: Can a python script edit itself?

As garvan says, it can be done without too much difficulty, but the currently executing copy of the code is unaffected. A more usual way of modifying the behavior of a running script is an appropriate conditional within the script! :) Of course, If you have a script that is scheduled to run periodic...
by pfletch101
Mon Mar 16, 2020 12:41 am
Forum: Beginners
Topic: Python script results in webpage
Replies: 1
Views: 208

Re: Python script results in webpage

This does sound like a good use for a database, which would also allow you to pull historical data if you wished. I would create a SQLite database with a single table with a field for the timestamp and a field for each of the data items you are reading in. Modify your script to save the data to the ...
by pfletch101
Tue Feb 18, 2020 1:44 am
Forum: Automation, sensing and robotics
Topic: Portable wireless temperature sensors
Replies: 4
Views: 642

Re: Portable wireless temperature sensors

There are a lot of temperature/humidity (and other) sensors which report their readings wirelessly on the 433 MHz band. Ambient Weather makes a number of models, but there are others. The transmissions of most of the more common ones can be picked up by means of a Software Controlled radio plugged i...
by pfletch101
Mon Feb 17, 2020 7:54 pm
Forum: General discussion
Topic: Update OS in place?
Replies: 5
Views: 300

Re: Update OS in place?

Ask your friend (since he has it running) what OS is on the SD he copied for you. It is most likely RetroPi, which (AFAIK) doesn't yet officially support the Pi 4, though I believe that it may be possible manually to install that OS on the newest Pi.
by pfletch101
Sat Feb 08, 2020 10:05 pm
Forum: Python
Topic: Can you call a url from a python script?
Replies: 10
Views: 1054

Re: Can you call a url from a python script?

Thanks for all the suggestions. I will try them hopefully soon. One thing to clarify is what I meant by hard coding. My present plan is to put the scheduled curtain openings in the crontab. Of course (at least to my understanding) is I will have to edit the crontab from linux. I would prefer to giv...
by pfletch101
Sat Feb 08, 2020 4:38 pm
Forum: General discussion
Topic: Email - a bit of hep needed.
Replies: 3
Views: 278

Re: Email - a bit of hep needed.

There are at least two possible issues: 1) If you are relaying to all destinations through the SMTP server for your domain (assuming that it is hosted by an ISP on the general internet), you may need to tell postfix that it is the mail server for your domain (not for a subdomain). I have had problem...
by pfletch101
Sat Jan 11, 2020 5:21 pm
Forum: General discussion
Topic: Remote desktop error
Replies: 2
Views: 225

Re: Remote desktop error

AFAIK, Remote Desktop is a Windows program which allows a Windows system to connect to and control another Windows system. To connect to your Pi's (virtual) desktop from your Windows system, you would normally need to download and install the RealVNC client software from https://www.realvnc.com/en/c...
by pfletch101
Sun Dec 22, 2019 8:23 pm
Forum: Beginners
Topic: Cannot get headless SSH to work.
Replies: 17
Views: 1032

Re: Cannot get headless SSH to work.

Windows (some versions on some days with certain planetary alignments) can be funky about creating zero length files. I.e., what I am arguing is that whichever poster was saying that creating a zero length file doesn't work did, probably, fail to create any file at all. That could be. I obviously c...
by pfletch101
Sun Dec 22, 2019 4:39 pm
Forum: Beginners
Topic: Cannot get headless SSH to work.
Replies: 17
Views: 1032

Re: Cannot get headless SSH to work.

rpdom wrote:
Sun Dec 22, 2019 4:25 pm
Zero length file works for me every time.
Out of interest, do you create the file on a Windows system or on a Pi or other Unix system? The issue I had could be related to something that Windows does (or didn't/doesn't do) in creating 'empty' directory entries.
by pfletch101
Sun Dec 22, 2019 4:18 pm
Forum: Beginners
Topic: Cannot get headless SSH to work.
Replies: 17
Views: 1032

Re: Cannot get headless SSH to work.

You say you created an 'empty' ssh file. Do you mean that literally? My experience is that a literally empty (zero length) file doesn't work to enable ssh on first boot. The file must contain at least one character (which can be a space character). Should work even if the file is empty I agree that...
by pfletch101
Sun Dec 22, 2019 3:23 pm
Forum: Other projects
Topic: Manufacturing Pacing Program
Replies: 7
Views: 822

Re: Manufacturing Pacing Program

In addition, the number of people at a station varies day to day, so based on how many people are working on assembly, the countdown time is more or less. Surely, the reasonable minimum time needed to complete the assembly of a part is a constant . I don't suddenly become able to work faster becaus...
by pfletch101
Sun Dec 22, 2019 3:02 pm
Forum: Beginners
Topic: Cannot get headless SSH to work.
Replies: 17
Views: 1032

Re: Cannot get headless SSH to work.

You say you created an 'empty' ssh file. Do you mean that literally? My experience is that a literally empty (zero length) file doesn't work to enable ssh on first boot. The file must contain at least one character (which can be a space character).
by pfletch101
Sun Dec 22, 2019 2:52 pm
Forum: Beginners
Topic: how to get a systemd mount to come up automatically?
Replies: 4
Views: 385

Re: how to get a systemd mount to come up automatically?

Systemd is probably trying to start it before a prerequisite service (probably some aspect of networking) is up and running. Try adding After=network-online.target to the [Unit] section of the systemd unit file. This should actually wait until the network is fully up and running. Other network targe...
by pfletch101
Wed Dec 18, 2019 3:31 pm
Forum: General discussion
Topic: PLEASE HELP!! /// SEEKING PROGRAMMING EXPERIENCE ADVICE!!
Replies: 90
Views: 4560

Re: PLEASE HELP!! /// SEEKING PROGRAMMING EXPERIENCE ADVICE!!

PeterO, Programme flow is not invisibly affected by line indentation,... Certainly it is. Python block delimiting is done with new lines and spaces. Non-printing characters. That is to say invisible. I have programmed in many languages, from Apple and 8088/6 assembly language, through Fortran, vari...
by pfletch101
Tue Dec 17, 2019 3:13 pm
Forum: Troubleshooting
Topic: RealVNC has suddenly become flaky
Replies: 9
Views: 578

Re: RealVNC has suddenly become flaky

The RealVNC problems seem to be specific to my main desktop system. I can't retest RealVNC from elsewhere with the original Pi because installing TightVNC automatically uninstalls the RealVNC server, but there are no apparent problems connecting to a different Pi after installing the RealVNC viewer ...
by pfletch101
Mon Dec 16, 2019 9:45 pm
Forum: Troubleshooting
Topic: RealVNC has suddenly become flaky
Replies: 9
Views: 578

Re: RealVNC has suddenly become flaky

I don't use Chrome - Google knows enough about me already. I have now installed TightVNC on both ends, which seems to be working for now. However, its viewer has the supremely irritating 'feature' of requiring that you enter the TightVNC connection password every time you want to connect - there app...
by pfletch101
Mon Dec 16, 2019 8:51 pm
Forum: Troubleshooting
Topic: RealVNC has suddenly become flaky
Replies: 9
Views: 578

Re: RealVNC has suddenly become flaky

It gets worse! I uninstalled the viewer from my Windows system, removed all traces of it that I could find in the Registry, rebooted, and reinstalled the latest version. I could (and did) connect to my running Pi without problems. I just checked again, and the viewer is back to the same misbehavior.

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