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by Eirikur
Mon Feb 17, 2020 5:28 am
Forum: General discussion
Topic: error installing docker
Replies: 3
Views: 105

Re: error installing docker

I believe this is how I installed a working docker on Buster on Pi 4: https://dev.to/rohansawant/installing-docker-and-docker-compose-on-the-raspberry-pi-in-5-simple-steps-3mgl BTW: Docker does not work on a Zero. They forgot to compile one of the binaries for that CPU. I can dig up the work-around ...
by Eirikur
Sun Feb 16, 2020 6:39 am
Forum: General discussion
Topic: SD card copier: homebrew version
Replies: 4
Views: 217

Re: SD card copier: homebrew version

The two lines below are my solution in this space. I find it intellectually and practically easier to just think and act in terms of copying the all the bits on the card to a file or from a file to a card or from card to card. The linux dd command is the way to do that and if I just told you that yo...
by Eirikur
Sun Feb 16, 2020 6:20 am
Forum: General discussion
Topic: GPIO programing
Replies: 9
Views: 280

Re: GPIO programing

Well, in the code you show, after you reverse your list, your program just ends. Python's list.reverse() function does reverse the list in--place, that is to say it modifies the list rather than returning a new list. Your usage is probably correct, but the control flow of your program never makes us...
by Eirikur
Thu Feb 13, 2020 11:19 pm
Forum: General discussion
Topic: Measuring energy consumption with a Pi
Replies: 2
Views: 165

Re: Measuring energy consumption with a Pi

You could do something like a simple write to a one-column CSV file, and then later calculate the total with a program or a spreadsheet. Or do you want to do this without an addtional step? I think this would not be hard using the rpi_backlight module if your monitor is an Official Touchscreen. What...
by Eirikur
Mon Feb 10, 2020 12:20 am
Forum: General discussion
Topic: Local only WiFi AP for RPi4 - how?
Replies: 8
Views: 247

Re: Local only WiFi AP for RPi4 - how?

I was impressed by the Balena wifi-connect solution. I adopted it in a retail-of-digital-goods system. You might find parts of it useful.
https://github.com/balena-io/wifi-connect
by Eirikur
Thu Feb 06, 2020 9:12 pm
Forum: General discussion
Topic: RPi 4 audio bit rate and sample rate
Replies: 13
Views: 411

Re: RPi 4 audio bit rate and sample rate

What reason do you have for such overkill data size/rate for audio? That's so very far beyond what's required to exceed the best human hearing in perfect anechoic environments. This is an area where specs become a sort of fantasy thing. Inside professional audio mixers, you might need 24 or 32 bit i...
by Eirikur
Wed Jan 29, 2020 10:29 pm
Forum: Python
Topic: How to combine two codes together
Replies: 1
Views: 196

Re: How to combine two codes together

It appears that you are trying to combine snippets of Python. I very strongly advise you to read a chapter or two about the Python language, or at least an online tutorial. Your sensor snippet is an infinite loop, so it's never going to execute anything that comes after it. You don't appear to know ...
by Eirikur
Thu Jan 09, 2020 9:02 pm
Forum: General discussion
Topic: PCIe over cable standard. I didn't know that was a thing.
Replies: 22
Views: 1034

PCIe over cable standard. I didn't know that was a thing.

People have been talking about that PCIe interface that is not exposed on Pi4B. The Foundation may be far ahead of me here, but I want to make sure that you know about this idea. It might be worth adding a low-cost connector compatible with the PCIe over cable scheme. This might be possible where a ...
by Eirikur
Wed Jan 08, 2020 12:54 am
Forum: General discussion
Topic: Latest Version of Thunderbird on a Raspberry Pi
Replies: 5
Views: 368

Re: Latest Version of Thunderbird on a Raspberry Pi

Actually, those versions of Thunderbird are all for Intel CPUs. For Raspbian you require 32-bit ARM which is ARMF. You could build from source, of course. I don't think that Mozilla builds ARM versions for you. My personal solution for running both Firefox and Thunderbird is to run Ubuntu Server on ...
by Eirikur
Thu Jan 02, 2020 2:30 am
Forum: General discussion
Topic: Camera gestures
Replies: 1
Views: 189

Re: Camera gestures

OpenCV is one place to start.
by Eirikur
Fri Dec 20, 2019 3:57 am
Forum: General discussion
Topic: PiHole perforamance effect on non-PiHole Pi.
Replies: 10
Views: 467

Re: PiHole perforamance effect on non-PiHole Pi.

Pi-hole is blazing fast. It's a simple, optimized, program. Because it works as a DNS server, your requests and the web page that comes back don't go through it. You are quite right. Your browsing will go faster. It doesn't need a fast machine. Mine is a 3B+, which is overkill.
by Eirikur
Fri Dec 20, 2019 3:50 am
Forum: General discussion
Topic: Steer multi raspberry pis with 1
Replies: 8
Views: 468

Re: Steer multi raspberry pis with 1

You really have to define what you mean by "steer." Docker, for example, doesn't provide any resource sharing, at all. You still have to tell docker what to run where, and install docker and your software on every pi. The result is pretty much the same as installing the MPI library and your program ...
by Eirikur
Mon Dec 16, 2019 9:26 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Sending MIDI over TX
Replies: 12
Views: 682

Re: Sending MIDI over TX

This is really the hard way to do MIDI and you have to make your own cables. MIDI is not a standard computer serial port. It uses a current loop, and optical isolators. You might be able to kludge it, but you'd need electronics knowledge. A USB-to-MIDI adapter will save you a lot of trouble. Look up...
by Eirikur
Mon Dec 16, 2019 9:21 am
Forum: Graphics, sound and multimedia
Topic: Super Collider spontaneous start .... ?
Replies: 1
Views: 252

Re: Super Collider spontaneous start .... ?

The crude way would be to rename the supercollider program so that the script that's starting it will fail. You don't actually know what's happening, though. I suggest learning about the systemd startup system that is used on raspbian and disabling the services that might be causing your problem. Yo...
by Eirikur
Mon Dec 16, 2019 9:18 am
Forum: Graphics, sound and multimedia
Topic: Is Raspberry Pi 3 B+ better than Raspberry Pi 4 B for USB DACs?
Replies: 7
Views: 736

Re: Is Raspberry Pi 3 B+ better than Raspberry Pi 4 B for USB DACs?

An oscilloscope would answer the question for you. Unless the hash is really quite bad, I don't expect that someone is going to hear it. You can use standard magnetic choke interference filters on your USB cables, or solder-up a capacitor across the power and ground lines of a USB cable.
by Eirikur
Mon Dec 16, 2019 9:11 am
Forum: General discussion
Topic: Auto updating a single software
Replies: 2
Views: 220

Re: Auto updating a single software

If you only want to update one thing, the apt command can do that. Let's say you want to update the chrominum browser. "sudo apt install --upgrade chrominum-browser"
by Eirikur
Mon Dec 16, 2019 9:08 am
Forum: General discussion
Topic: Security
Replies: 3
Views: 248

Re: Security

Using the apt package system's update and upgrade has the same security status as your original download of the card image. Update just updates your pi with the latest version information. Upgrade downloads and installs updated software. You are trusting the same people that made the image on your c...
by Eirikur
Mon Dec 16, 2019 8:57 am
Forum: General discussion
Topic: OS to run pyqt5 script
Replies: 1
Views: 102

Re: OS to run pyqt5 script

Raspbian is a typical debian-based Linux operating system that uses systemd for the startup process. Knowing that, you can Google for creating simple systemd service files. A service file tells systemd how to start your program as a service or daemon. That is basically what you want. This page gives...
by Eirikur
Mon Dec 16, 2019 8:25 am
Forum: General discussion
Topic: PLEASE HELP!! /// SEEKING PROGRAMMING EXPERIENCE ADVICE!!
Replies: 90
Views: 3346

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

Here's a tool that can help you figure out Python things using Python's introspection features. I'm talking about bpython. If you use it and type "import math" hit return and then type "math." it will show you all the functions in the math library. I use this all the time to dig into unfamiliar libr...
by Eirikur
Sat Nov 23, 2019 2:50 am
Forum: General discussion
Topic: USB Device name
Replies: 5
Views: 284

Re: USB Device name

You could do umount to dismount the USB stick, but you'd still need another command to shutdow. Shutdown should do it for you.
by Eirikur
Sat Nov 23, 2019 2:32 am
Forum: Advanced users
Topic: DVFS Firmware
Replies: 85
Views: 10990

Re: DVFS Firmware

I updated one of my 4Bs to the latest firmware via rpi-update. Overclocking to 2147 with no GPU overclock reports a speed of 2294, with idle at 655 and two increments between. I don't know if this is the actual speed, or if there's reporting issue. I'm using the pi-enhanced htop, which I believe get...
by Eirikur
Fri Nov 22, 2019 4:45 am
Forum: General discussion
Topic: automatic activation of a terminal code
Replies: 8
Views: 429

Re: automatic activation of a terminal code

ntp is enabled by default. What is your offset seen in the RPi from your correct local time?

>>> Have you set your time zone? That seems the most likely cause to me. You can use raspi-config in a terminal window or use the desktop Preferences applet.
by Eirikur
Sun Nov 17, 2019 12:27 am
Forum: General discussion
Topic: Is there a function to check that the Pi camera is on?
Replies: 7
Views: 385

Re: Is there a function to check that the Pi camera is on?

In case the original poster isn't writing a program, s/he can use the Raspbian utilities raspistill or rasbpivid, which will return an error status if the camera isn't present and responding. You can detect an error status in a shell (Bash) script, Google will find plenty of pages on how to do that.
by Eirikur
Sun Nov 17, 2019 12:04 am
Forum: General discussion
Topic: RPI4: Why is everything still 32-bit?
Replies: 183
Views: 12564

Re: RPI4: Why is everything still 32-bit?

Use Ubuntu Server 64-bit and install what you want from there. Burn the 64-bit AARCH64 image with Pi3 in the name to an SDcard. Log in on the console (there is no windowing system) and install mate-desktop-environment. Be happy. Works for me. On the Pi 4GB, until an update release, you must set: tot...
by Eirikur
Wed Nov 13, 2019 1:44 am
Forum: General discussion
Topic: Scaling Down a prototype
Replies: 10
Views: 509

Re: Scaling Down a prototype

If it is failing on loading that file into a Python array, don't do it that way. You could search through the file using standard Unix command line utilities launched by your Python code. You could also read through the file, using Python, setting your buffer size to something that will fit in memor...

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