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by MarkDH102
Thu Dec 19, 2019 7:15 am
Forum: Python
Topic: Outputting text to centre of screen?
Replies: 4
Views: 252

Re: Outputting text to centre of screen?

Or you could investigate the 'curses' library...
by MarkDH102
Thu Dec 19, 2019 7:12 am
Forum: Beginners
Topic: Multipage PDF from command line?
Replies: 4
Views: 334

Re: Multipage PDF from command line?

Have you tried typing

Code: Select all

man fbi
in the terminal window?
by MarkDH102
Thu Dec 19, 2019 7:10 am
Forum: Beginners
Topic: Cannot save a file in text editor - Access Denied
Replies: 4
Views: 243

Re: Cannot save a file in text editor - Access Denied

Open up a terminal window. Type: cd /etc/apt/source.list.d sudo nano yourfilename When you are done, to save press CTRL-X and then Y. To modify/create files in these 'system' areas you need to be a super user (I think that's the correct term), hence running all file type commands in there preceded b...
by MarkDH102
Mon Dec 16, 2019 4:48 pm
Forum: General discussion
Topic: Slow serial communication between Raspberry Pi 3+ and Arduino Mega
Replies: 29
Views: 796

Re: Slow serial communication between Raspberry Pi 3+ and Arduino Mega

I can't believe the Mega is slow. I use one to read masses of serial data (at 115200 baud) from 2 different devices, manipulate it and then store it away. It also has time to update an I2C 480*320 colour LCD. I did increase the size of the serial buffers somewhat but that shouldn't be necessary here...
by MarkDH102
Mon Dec 16, 2019 4:28 pm
Forum: General discussion
Topic: Slow serial communication between Raspberry Pi 3+ and Arduino Mega
Replies: 29
Views: 796

Re: Slow serial communication between Raspberry Pi 3+ and Arduino Mega

Code: Select all

if(rc==0 & Serial.available())
Did you actually mean (note the double &&)

Code: Select all

if(rc==0 && Serial.available())
by MarkDH102
Mon Dec 16, 2019 7:27 am
Forum: General discussion
Topic: xdotool and Buster errors
Replies: 9
Views: 397

Re: xdotool and Buster errors

I had a light bulb moment last night.
I remember why I didn't originally use "--geometry" while launching lxterminal.
Because it didn't centre the terminal window on the screen.
It does appear to now. It was way back in Jessie when I tried it before...
by MarkDH102
Sun Dec 15, 2019 7:25 am
Forum: General discussion
Topic: xdotool and Buster errors
Replies: 9
Views: 397

Re: xdotool and Buster errors

Thanks all for your input. Just to let you know. It had never happened to me before while using Jessie & Stretch. But it happens EVERY time I open a terminal window and type in the command from above in Buster. As for the geometry command for lxterminal, I just didn't know about it. But as you say, ...
by MarkDH102
Sat Dec 14, 2019 7:01 am
Forum: General discussion
Topic: xdotool and Buster errors
Replies: 9
Views: 397

Re: xdotool and Buster errors

Paeryn

Many thanks for your sterling efforts. I couldn't even begin to decode the "error" message I posted.
I will set to working out how to zoom the window programmatically...
by MarkDH102
Fri Dec 13, 2019 5:14 pm
Forum: General discussion
Topic: xdotool and Buster errors
Replies: 9
Views: 397

Re: xdotool and Buster errors

Sorry about the code tag thing, but I just wanted to show the error...
What led you to remove '--usehints' ???
However, when I remove it, I end up with a tiny window...
by MarkDH102
Fri Dec 13, 2019 5:01 pm
Forum: General discussion
Topic: xdotool and Buster errors
Replies: 9
Views: 397

xdotool and Buster errors

Standard Buster. Pi2B. Completely up to date. sudo apt-get install xdotool. Open a terminal window (don't resize it) and type : xdotool.jpg This worked fine under Jessie and Stretch. I call it from some python code to resize the terminal window on startup of the Pi. I use curses within the terminal ...
by MarkDH102
Thu Dec 12, 2019 7:23 am
Forum: Beginners
Topic: How to connect with ESP8266 and Raspberry pi
Replies: 4
Views: 195

Re: How to connect with ESP8266 and Raspberry pi

I too use MQTT with a Pi2B and a few ESP8266. My PI is connected to my amplifier and runs "OK GOOGLE" voice recognition software that allows me to play locally stored music. The ESP8266 are embedded within plastic pattress boxes along with a small PSU and a relay and allow me to switch mains to the ...
by MarkDH102
Sat Nov 30, 2019 6:58 am
Forum: Beginners
Topic: How to keep Pi 3 off when power is applied
Replies: 4
Views: 222

Re: How to keep Pi 3 off when power is applied

hippy

Thanks for the clarification.
I do use UPS (of a kind) but would be happier not to.
Plus I just have too many Pi's dotted around the house to buy UPS's for every one of them...
by MarkDH102
Fri Nov 29, 2019 4:57 pm
Forum: Beginners
Topic: How to keep Pi 3 off when power is applied
Replies: 4
Views: 222

Re: How to keep Pi 3 off when power is applied

This is interesting. Does it work with a Pi0W? My intention will be to boot manually, then throw a switch to short the "RUN" pin to 0V. So if we have a (frequent) power cut, my Pi will not re-boot (I presume no access to the SD card is performed?) when the power comes back up. And I will then go to ...
by MarkDH102
Thu Nov 28, 2019 2:56 pm
Forum: General discussion
Topic: MQTT controlling multiple devices [SOLVED]
Replies: 0
Views: 85

MQTT controlling multiple devices [SOLVED]

Didn't see the ClientID initialiser in the ESP8266 code!!! Running up to date Stretch on a Pi2B. Running MQTT mosquito broker. Running a python app that connects ok to the broker. Running a single ESP8266 that also connects ok to the broker on the Pi. (All on a local network). Controlling an output ...
by MarkDH102
Mon Nov 18, 2019 7:32 am
Forum: Python
Topic: Logging Python Traceback
Replies: 1
Views: 146

Re: Logging Python Traceback

From the Python interpreter, you will know the line that the error is occurring in and also the exception type. I would encapsulate that line (or lines) in a try except finally block. My example is for connecting the SMTP server. try : server=smtplib.SMTP('smtp-mail.outlook.com', 587) except (gaierr...
by MarkDH102
Tue Nov 12, 2019 7:32 am
Forum: General discussion
Topic: Scaling Down a prototype
Replies: 10
Views: 473

Re: Scaling Down a prototype

I don't know about the Google API, but the Google AIY does NOT work on a Pi0 / 0W. I did the same as you (I was controlling relays to switch mains) and scaled a Pi3 solution down to a Pi0W. Boxed it all up. Made a super job of it (unlike me). Powered it on and found that the AIY stuff is compiled fo...
by MarkDH102
Mon Nov 11, 2019 7:31 am
Forum: General discussion
Topic: Two adruino are connected to the raspberry via usb, but one is reconnected during processing code is running
Replies: 3
Views: 166

Re: Two adruino are connected to the raspberry via usb, but one is reconnected during processing code is running

The only thing that I can see is an undervoltage on the Pi. How are you powering the Arduinos? 3V3 or 5V? From the Pi or from a separate power supply? Maybe the voltage on the Arduino is dropping enough to cause the BOD (brown out detector) on the Arduino ATMEGA328 chip to become activated thus forc...
by MarkDH102
Thu Nov 07, 2019 7:20 am
Forum: General discussion
Topic: Interesting interview with Eben in Physics World
Replies: 41
Views: 2912

Re: Interesting interview with Eben in Physics World

In terms of using the Pi in an industrial environment, I cannot believe it would be in any kind of "critical" control type of operation - just monitoring as stated in the article. The SD card solution is just too unreliable for 24/7 running...and each Pi would need a UPS plus some really good noise ...
by MarkDH102
Sat Nov 02, 2019 7:17 pm
Forum: Troubleshooting
Topic: Do I have a problem - looking at this bit of syslog?
Replies: 3
Views: 294

Re: Do I have a problem - looking at this bit of syslog?

Hi epoch1970 Thanks for that. I use an official Pi PSU and can see a good solid 5V on the board. But I have now put a monitoring device on to see if it varies. I do run headless. And for that reason, I need to run haveged (I don't know why) to produce enough randomness for VNC to work properly. If I...
by MarkDH102
Sat Nov 02, 2019 7:21 am
Forum: Troubleshooting
Topic: Do I have a problem - looking at this bit of syslog?
Replies: 3
Views: 294

Do I have a problem - looking at this bit of syslog?

My Pi0 with Stretch has been doing something odd for a few months now. My python application logs climate information and has run successfully for a number of years. In the last few months at random times of the day (not every day), I seem to get a lockup where my data is not recorded and the CPU te...
by MarkDH102
Mon Oct 21, 2019 7:29 am
Forum: Off topic discussion
Topic: How can I make a Pi0W into a bluetooth server using python?
Replies: 9
Views: 2482

Re: How can I make a Pi0W into a bluetooth server using python?

'C' code (Arduino) for my ESP32 (A Heltec Kit32 with OLED) - as promised. A bit rough and ready but it works with the Pi code that Douglas6 posted. /* * Program to operate ESP32 in client mode and get served information from a Raspberry Pi * Program by: Mark Hollingworth * The code for the Raspberry...
by MarkDH102
Sat Oct 19, 2019 6:24 am
Forum: Off topic discussion
Topic: How can I make a Pi0W into a bluetooth server using python?
Replies: 9
Views: 2482

Re: How can I make a Pi0W into a bluetooth server using python?

HI Douglas6 I have got it working now and will post the 'C' code that works on an ESP32 when I have tidied it up so that other people may make use of it. Thanks for the advice about connecting. That is the conclusion that I had arrived at. I can't profess to fully understand what is going on in the ...
by MarkDH102
Thu Oct 17, 2019 6:23 am
Forum: Off topic discussion
Topic: How can I make a Pi0W into a bluetooth server using python?
Replies: 9
Views: 2482

Re: How can I make a Pi0W into a bluetooth server using python?

Hi Douglas6

It does exactly what I want. Thanks. It works as advertised on the app you suggested for the Android phone and I see it as a device on my ESP32.
Now I've got to work out why I can't see the services on my ESP32, but that's my problem now...

Regards Mark
by MarkDH102
Thu Oct 17, 2019 6:19 am
Forum: General discussion
Topic: Display lxterminal at specific screen location
Replies: 2
Views: 224

Re: Display lxterminal at specific screen location

I use xdotool. You will have to install it. However, I run it from within a python script that runs in the terminal window and call it using : import os os.system("xdotool getactivewindow windowmove 40 35 windowsize --usehints 165 43") I guess you can call it from the shortcut but I don't know how t...
by MarkDH102
Wed Oct 16, 2019 6:14 am
Forum: Off topic discussion
Topic: How can I make a Pi0W into a bluetooth server using python?
Replies: 9
Views: 2482

Re: How can I make a Pi0W into a bluetooth server using python?

Hi Douglas6

Thanks for the link. I've downloaded and will be playing shortly. I like a well documented GitHub repository. Many thanks.

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