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by MarkDH102
Wed Mar 13, 2019 11:16 am
Forum: Troubleshooting
Topic: Pi0 W showing "no wireless interface" and won't connect via VNC
Replies: 2
Views: 221

Re: Pi0 W showing "no wireless interface" and won't connect via VNC

I've now put the SD card back in the original Pi0 W and lo and behold it is no longer seeing the WiFi in that one either.
What on earth could I have done wrong?
Incredibly frustrating - all resulting from an extremely brief power cut.
Thank goodness most of my stuff has been migrated to esp32's now...
by MarkDH102
Wed Mar 13, 2019 9:22 am
Forum: Troubleshooting
Topic: Pi0 W showing "no wireless interface" and won't connect via VNC
Replies: 2
Views: 221

Pi0 W showing "no wireless interface" and won't connect via VNC

My router lists the device. However, if I plug in a (non powered) 3 port USB hub with ethernet (not connected to anything), I am able to VNC in over the WiFi with no problems ??? It still says "no wireless interfaces" and only shows the ethernet connector icon in the menu bar. But it does show wirel...
by MarkDH102
Mon Mar 11, 2019 7:10 am
Forum: Python
Topic: Send hex commands via uart port
Replies: 4
Views: 1638

Re: Send hex commands via uart port

The code looks fine to me. I use exactly the same type of thing to talk to a serial LCD. I guess you have the baud rate etc. correct for the camera. It strikes me that the 2 byte command you are sending is a bit "light". Are there no checksums involved or message terminating characters like carriage...
by MarkDH102
Wed Mar 06, 2019 5:32 pm
Forum: Troubleshooting
Topic: How to fix WiFi failure without rebooting
Replies: 2
Views: 181

Re: How to fix WiFi failure without rebooting

To turn off power saving mode with Edimax WiFi dongle, I do the following :

sudo nano /etc/modprobe.d/8192cu.conf

And add the 2 lines below then save.

# Disable Power Management
options 8192cu rtw_power_mgnt=0 rtw_enusbss=0

I too was plagued by the same problem, but not since doing this.
by MarkDH102
Wed Mar 06, 2019 5:25 pm
Forum: General discussion
Topic: Raspberry Pi3 connectivity from mobile
Replies: 4
Views: 283

Re: Raspberry Pi3 connectivity from mobile

You might wish to try weaved.com
I used it for something similar a while back.
I used it a while back. I have no idea if it still works the way Linux keeps changing the goalposts...
by MarkDH102
Sun Mar 03, 2019 7:17 am
Forum: Beginners
Topic: High CPU usage?
Replies: 7
Views: 783

Re: High CPU usage?

In Python : x = 0 while True : x = x + 1 Will use 100% CPU (on a Pi0) or 25% (on a 4 core Pi model). import time x = 0 while True : x = x + 1 time.sleep(1) # 1 second Will use next to no processing power. However while the sleep is active, your code is not running. Even using (0.01) (10mS) in the sl...
by MarkDH102
Sun Mar 03, 2019 6:59 am
Forum: AIY Projects
Topic: Does Google AIY still work on the Raspberry Pi?
Replies: 7
Views: 998

Re: Does Google AIY still work on the Raspberry Pi?

Also, Dougie, I assume you did not use Google's image file, but instead worked through their HACKING (https://github.com/google/aiyprojects-r ... HACKING.md) instructions? I used the hacking method and had no issues getting it to work with my own microphone (a USB one from a Nintendo Wii game!) and...
by MarkDH102
Fri Mar 01, 2019 7:10 am
Forum: AIY Projects
Topic: Does Google AIY still work on the Raspberry Pi?
Replies: 7
Views: 998

Re: Does Google AIY still work on the Raspberry Pi?

Yes, I found that link yesterday morning and went from scratch. Another complication was that my authorisation key had expired (they do after 6 months of activity apparently). But yesterday morning, I did finally get it all back up and running. Of course, my original code needed some modification th...
by MarkDH102
Thu Feb 28, 2019 12:20 pm
Forum: AIY Projects
Topic: Does Google AIY still work on the Raspberry Pi?
Replies: 7
Views: 998

Re: Google AIY - I've fallen down the LINUX rabbit hole...

Ok, with the original Stretch image from early 2018 that used to work, having been prompted by errors reported by my Python3 app I have installed - one at a time - each one inducing a new error : pip3 install google-auth pip3 install grpcio pip3 install google-cloud-storage pip3 install grpc However...
by MarkDH102
Tue Feb 26, 2019 12:28 pm
Forum: AIY Projects
Topic: Does Google AIY still work on the Raspberry Pi?
Replies: 7
Views: 998

Does Google AIY still work on the Raspberry Pi?

Well, I tried at the weekend to get AIY running on my Pi3 with an up to date Stretch. I followed some instructions from Feb 2018. No joy. All kinds of errors. So, I then dug out a Stretch image that I had successfully used to control lights and play music etc from Christmas 2018. No joy!!! All kinds...
by MarkDH102
Mon Feb 18, 2019 1:55 pm
Forum: General discussion
Topic: Problems with time ... yet again
Replies: 8
Views: 531

Re: Problems with time ... yet again

Ok. Thanks. Is there a way of removing ntp and going back to the timesyncd service (which caused me issues in the first place)...
by MarkDH102
Mon Feb 18, 2019 1:35 pm
Forum: General discussion
Topic: Problems with time ... yet again
Replies: 8
Views: 531

Re: Problems with time ... yet again

Thanks for that.
There are no entries in the journal. I have restarted the service and it has made no difference.
time1.png
time1.png (12.6 KiB) Viewed 392 times
by MarkDH102
Mon Feb 18, 2019 1:19 pm
Forum: General discussion
Topic: Problems with time ... yet again
Replies: 8
Views: 531

Re: Problems with time ... yet again

Once again, the time on my Pi has gone AWOL. It was wrong at 7:00AM this morning and is still wrong now. It has a good internet connection. Pi0W Stretch - completely up to date. The unit runs 24/7. The router it connects to is switched off between the hours of 22:00 and 06:00. The time here is curre...
by MarkDH102
Fri Feb 15, 2019 6:13 pm
Forum: Advanced users
Topic: connectivity questions
Replies: 6
Views: 454

Re: connectivity questions

I have no idea what SCP is, but surely setting the 2 Pi's to use a static IP address should work?
Also, if you have frequent power interruptions (as I do) then you stand the risk of corrupting the SD card.
I use simple UPS's on all my Pi's. I've learned the hard way!
by MarkDH102
Sat Feb 02, 2019 7:21 am
Forum: Python
Topic: Not sure if this is possible...
Replies: 11
Views: 773

Re: Not sure if this is possible...

I use this method to start Python apps in a terminal window at start up : Add line : @/usr/bin/python /home/pi/MarksStuff/NameOfProg.py To : autostart file in ~/.config/lxsession/LXDE-pi/ Using : nano ~/.config/lxsession/LXDE-pi/autostart To run in a terminal window (sudo is optional): @lxterminal -...
by MarkDH102
Tue Jan 15, 2019 7:36 am
Forum: General discussion
Topic: GUI to Run two programs
Replies: 46
Views: 2948

Re: GUI to Run two programs

I use a menu across the top of the tkinter window to open different windows thus : menubar = Menu(root) graphmenu = Menu(menubar, tearoff=0) graphmenu.add_command(label="Temperatures", command=createTemperatureWindow) graphmenu.add_command(label="Humidities", command=createHumidityWindow) menubar.ad...
by MarkDH102
Sun Jan 13, 2019 7:15 am
Forum: Troubleshooting
Topic: OLED error.
Replies: 6
Views: 689

Re: OLED error.

Have you tried the i2c tools? They should be installed by default. From a terminal window, run : i2cdetect -y 1 If I have understood correctly, you should see an entry at 3C. If there is another entry in the list, and you have no other devices connected to the Pi, then the address of the display is ...
by MarkDH102
Sat Jan 12, 2019 9:22 pm
Forum: Troubleshooting
Topic: OLED error.
Replies: 6
Views: 689

Re: OLED error.

I think you need to go to the preferences > raspberry pi configuration menu and enable the i2c interface.
by MarkDH102
Wed Jan 02, 2019 1:51 pm
Forum: General discussion
Topic: Attach LED to show when OS is running (headless)
Replies: 5
Views: 376

Re: Attach LED to show when OS is running (headless)

Why take an additonal LED?
Because it is in a box (and there are 3 other LED's indicating different states) :)
by MarkDH102
Wed Jan 02, 2019 7:28 am
Forum: Beginners
Topic: Displaying a graph and viewing it remotely
Replies: 5
Views: 535

Re: Displaying a graph and viewing it remotely

I do something a bit similar.
I use gnuplot (called from a python app) to generate the graphs and then display them in a tkinter window.
I then VNC in to my Pi to view the tkinter window.
by MarkDH102
Wed Jan 02, 2019 7:24 am
Forum: General discussion
Topic: Attach LED to show when OS is running (headless)
Replies: 5
Views: 376

Re: Attach LED to show when OS is running (headless)

I have a system that runs headless 24/7. In the Python application that it runs, it has a simple bit of Python code to toggle an LED every 10 seconds. I set the application running in LXDE autostart. Add line : @/usr/bin/python /home/pi/MarksStuff/NameOfProg.py To : autostart file in ~/.config/lxses...
by MarkDH102
Wed Jan 02, 2019 7:15 am
Forum: General discussion
Topic: How long do you guys keep your sd cards?
Replies: 8
Views: 785

Re: How long do you guys keep your sd cards?

Well, I have had a number of failures - Sandisk Ultra, Kingston, Lexar - over the years I've been using them in Pi's (24/7 running). Most of the cards are NOT written to by my applications. I would suggest you backup the card and tuck the back-up away somewhere. It is a pain rebuilding systems - as ...
by MarkDH102
Thu Dec 13, 2018 7:31 am
Forum: General discussion
Topic: Problems with time ... yet again
Replies: 8
Views: 531

Problems with time ... yet again

Pi0W full Stretch completely up to date. I didn't receive my email from my Pi this morning. I've just vnc'd in to find it's time is 6:07 (Actual time is 7:20). I tried changing timezone but it had no effect (I don't want to reboot the system). I have had to resort to : apt-get install ntp I also did...
by MarkDH102
Sat Dec 01, 2018 5:23 pm
Forum: Troubleshooting
Topic: Interrupt bouncing by using Accelerometer DATA_READY Interrupt
Replies: 3
Views: 316

Re: Interrupt bouncing by using Accelerometer DATA_READY Interrupt

If you are sampling at such a slow rate, it might be better to slow the device down. It can provide output from 3200Hz to 6.25Hz.
Use 6.25Hz and then make sure your interrupt runs in < 1/6.25s
I've not used this chip, so others might have better ideas...
by MarkDH102
Thu Nov 29, 2018 2:26 pm
Forum: Python
Topic: espeak in a python script
Replies: 6
Views: 1911

Re: espeak in a python script

I use espeak in virtually the same was as your example. I don' think there is a python module for espeak. You are just calling an application and passing it some parameters a bit like gnuplot. I might/could probably be wrong. In a function, within a while loop, I would read the text file line by lin...

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