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by Paul Hutch
Wed Apr 22, 2020 11:44 am
Forum: General discussion
Topic: What are the best micro sd card models for raspberry pi 4b?
Replies: 5
Views: 534

Re: What are the best micro sd card models for raspberry pi 4b?

There is also a model SDSQUNC-064G-AN6MA. It is the same except it does not come with an SD adapter. That is why it costs a little less. Based on the places I've found that offer that part number (not available direct from Sandisk/Western Digital or direct from Amazon) it appears that is the older ...
by Paul Hutch
Tue Apr 21, 2020 2:45 pm
Forum: General discussion
Topic: What are the best micro sd card models for raspberry pi 4b?
Replies: 5
Views: 534

Re: What are the best micro sd card models for raspberry pi 4b?

Due to the many variables involved, "best" varies between individuals. For me based on my personal weighting of, trust in the manufacturer, speed, lifetime, reliability, availability, and cost, I go for the newer model SanDisk Ultra cards with an A1 rating. For 64G that's currently SDSQUAR-064G-GN6MA.
by Paul Hutch
Sun Apr 12, 2020 3:18 pm
Forum: General discussion
Topic: Looking for a multi-port USB Hub to power multiple Raspi 4Bs
Replies: 10
Views: 738

Re: Looking for a multi-port USB Hub to power multiple Raspi 4Bs

While I 100% agree with the conclusions in your post the following is 100% false. spec compliant USB hubs won't deliver more than 0.5A per port (0.9A for USB 3). The USB specifications (available for free from USB.org) are very clear, the 500mA is a minimum and there is no maximum current specificat...
by Paul Hutch
Thu Apr 09, 2020 5:12 pm
Forum: General discussion
Topic: Recommendations for a USB Hub that can power the Pi
Replies: 10
Views: 665

Re: Recommendations for a USB Hub that can power the Pi

The best power requirement info to use is the official information from the RPF located here: https://www.raspberrypi.org/documentation/hardware/raspberrypi/power/README.md There you will see the recommended supply current, how much of the recommended current is available to USB peripherals, and the...
by Paul Hutch
Wed Apr 08, 2020 2:20 pm
Forum: General discussion
Topic: Poor practice to read from .txt file multiple times a minute?
Replies: 25
Views: 1204

Re: Poor practice to read from .txt file multiple times a minute?

great thank you You're very welcome. BTW - I should have mentioned before that checking the Linux Filesystem Hierarchy Standard is the best way to figure out where you should put files so that your applications have the broadest compatibility with different *nix distros. https://en.wikipedia.org/wi...
by Paul Hutch
Tue Apr 07, 2020 8:54 pm
Forum: General discussion
Topic: Poor practice to read from .txt file multiple times a minute?
Replies: 25
Views: 1204

Re: Poor practice to read from .txt file multiple times a minute?

mesand wrote:
Tue Apr 07, 2020 1:29 am
ok, currently the files im reading/writing too are all inside the directory I am using for my project. Should they be somewhere else in the file system?
If your program is running as root then use /run/

If your program is running as the default user pi then use /run/user/1000/
by Paul Hutch
Tue Apr 07, 2020 1:06 am
Forum: General discussion
Topic: Poor practice to read from .txt file multiple times a minute?
Replies: 25
Views: 1204

Re: Poor practice to read from .txt file multiple times a minute?

IMHO, it's best to use the /run tempfs (ramdisk) or sub-directories for files that need a lot a of repeated access. It will keep resource usage low and access speed super fast. A potential downside is that the file will not persist between boot cycles.
by Paul Hutch
Sun Mar 29, 2020 12:54 pm
Forum: Advanced users
Topic: What is the max micro sd card for Rasberry Pi 4 B / 4GB? can use a 64GB micro sd card like below? upper?
Replies: 16
Views: 1905

Re: What is the max micro sd card for Rasberry Pi 4 B / 4GB? can use a 64GB micro sd card like below? upper?

Rukbat wrote:
Sat Mar 28, 2020 4:47 pm
Think about it. As Paul Hutch reminded me, the bootloader ...
To clarify, It was jahboater who reminded you not me.
by Paul Hutch
Fri Mar 27, 2020 1:49 pm
Forum: General discussion
Topic: Old SD (or microSD) cards
Replies: 14
Views: 1080

Re: Old SD (or microSD) cards

Use them for archiving data like pictures. They should be able to hold the data at least 20 years. You'd have to be very methodical with records and storage. Geffers To make it easier to track and catalog the contents be sure to give each card a unique volume label and then use Virtual Volumes View...
by Paul Hutch
Thu Mar 26, 2020 10:01 pm
Forum: Off topic discussion
Topic: Call for help: looking to start a company - solar powered computer
Replies: 31
Views: 3197

Re: Call for help: looking to start a company - solar powered computer

A solar powered calculator is orders of magnitude lower in power consumption than even the lowest power microcontroller, let alone a microprocessor. They are usually built around custom chips designed to do only a solar powered calculator function. IIRC, a typical solar powered calculator chipset op...
by Paul Hutch
Thu Mar 26, 2020 12:45 pm
Forum: Advanced users
Topic: What is the max micro sd card for Rasberry Pi 4 B / 4GB? can use a 64GB micro sd card like below? upper?
Replies: 16
Views: 1905

Re: What is the max micro sd card for Rasberry Pi 4 B / 4GB? can use a 64GB micro sd card like below? upper?

Rukbat wrote:
Thu Mar 26, 2020 4:37 am
Formatted as FAT32, or as exFAT? (Just asking - you'd know, so you can save me time forcing the card to format as FAT32, or leaving it as exFAT and having it not work.)
Formatting is irrelevant because when the disk image is copied onto the card it wipes out all existing formatting.
by Paul Hutch
Tue Mar 24, 2020 11:26 pm
Forum: Advanced users
Topic: What is the max micro sd card for Rasberry Pi 4 B / 4GB? can use a 64GB micro sd card like below? upper?
Replies: 16
Views: 1905

Re: What is the max micro sd card for Rasberry Pi 4 B / 4GB? can use a 64GB micro sd card like below? upper?

I tried a SanDisk Ultra A1 400GB uSD card in aPi3B+ running Stretch Lite this past week and it appears to work fine (I bought the card for a different use but figured it would be fun to try it out).
by Paul Hutch
Wed Mar 11, 2020 7:42 pm
Forum: Advanced users
Topic: Pi wifi re/connection
Replies: 6
Views: 506

Re: Pi wifi re/connection

Many thanks for the reply Paul .. I was looking round in /proc to see if I could find a reference to the WAP being connected to ( and didnt find anything ) WiFi up/down status is recorded in syslog, most simple dropouts and connects are found by searching for messages that mention carrier in relati...
by Paul Hutch
Wed Mar 11, 2020 2:05 pm
Forum: General discussion
Topic: Rpi zero charger
Replies: 5
Views: 451

Re: Rpi zero charger

The official FAQ Power section has a lot of good information. https://www.raspberrypi.org/documentati ... /#pi-power
by Paul Hutch
Wed Mar 11, 2020 1:57 pm
Forum: Advanced users
Topic: Pi wifi re/connection
Replies: 6
Views: 506

Re: Pi wifi re/connection

After two years of extensively testing the resiliency of WiFi connections for a work project I can authoritatively state that the answer to 1 & 2 is: They are supposed to, and they usually do succeed, but they don't always succeed, so a definite maybe. :D This is from testing a dozen Pi's, various W...
by Paul Hutch
Tue Mar 10, 2020 12:59 pm
Forum: General discussion
Topic: Can I use Amazon's Power Adapter?
Replies: 15
Views: 863

Re: Can I use Amazon's Power Adapter?

Check the ratings printed on the particular unit you want to use. If the current rating is < 1.5A I wouldn't bother trying it. Of course how much current you'll need also depends on what USB devices and accessory HATs will be attached and how hard you'll push the Pi. I have an Amazon branded unit th...
by Paul Hutch
Mon Mar 09, 2020 10:01 pm
Forum: Advanced users
Topic: Raspberry Pi and Powerbank
Replies: 16
Views: 1324

Re: Raspberry Pi and Powerbank

Then I guess my Pi is faulty. I just did the measurements again to verify. When supplied with 4.96V on the USB-C-input, the thunderbolt appears: piundervoltage.jpg I previously had a similar observation with a fixed regulator which measured 4.99V. I can turn the voltage down all the way to at least...
by Paul Hutch
Mon Mar 09, 2020 3:41 pm
Forum: Advanced users
Topic: Raspberry Pi and Powerbank
Replies: 16
Views: 1324

Re: Raspberry Pi and Powerbank

I experimented previously with a Pi4B, put ~5V adjustable power supply to the +5V rail directly. The "under voltage" message still appears with 5.00V (according to my voltage meter), turning it up a bit to 5.05V or so removes the message. Not sure where the 4.65V fits in. IIRC (it's been a long whi...
by Paul Hutch
Sat Mar 07, 2020 1:15 pm
Forum: Advanced users
Topic: Simultaneous WiFi connections
Replies: 5
Views: 549

Re: Simultaneous WiFi connections

Make sure the two networks use different private IP address a ranges. e.g. 192.168.1.X/255.255.255.0 and 192.168.2.X/255.255.255.0
by Paul Hutch
Sat Mar 07, 2020 1:13 pm
Forum: Advanced users
Topic: Image File Utilities
Replies: 307
Views: 36181

Re: Image File Utilities

dsyleixa123 wrote:
Sat Mar 07, 2020 12:38 pm
where are my former posts?
Click the Search user’s posts link at your user profile page (click on your user name to open the profile).
by Paul Hutch
Sat Mar 07, 2020 1:07 pm
Forum: General discussion
Topic: A portable wifi nas
Replies: 4
Views: 435

Re: A portable wifi nas

Check out B&H's article for an excellent round up of off the shelf solutions. https://www.bhphotovideo.com/explora/photography/buying-guide/guide-to-portable-hard-drives-for-the-travel-photographer This is one of those cases where rolling your own may be more cost effective depending on your skill l...
by Paul Hutch
Sat Mar 07, 2020 12:47 pm
Forum: General discussion
Topic: SD Card Memory
Replies: 3
Views: 340

Re: SD Card Memory

It seems that your chosen OS distro is lacking the automatic file system expansion on first boot feature (Raspbian would expand to use the whole 128G during the first boot). You can manually do the file system expansion on the Pi from the command line. sudo raspi-config Choose: 7 Advanced Options A1...
by Paul Hutch
Sat Mar 07, 2020 12:21 pm
Forum: Advanced users
Topic: What is the best way to create compressed disk image?
Replies: 19
Views: 1296

Re: What is the best way to create compressed disk image?

Yes you could just use the same Pi with a second card setup for the image copy process. If you used an extra large second card you can even skip the external USB storage for storing the large disk images.
by Paul Hutch
Fri Mar 06, 2020 9:44 pm
Forum: Advanced users
Topic: What is the best way to create compressed disk image?
Replies: 19
Views: 1296

Re: What is the best way to create compressed disk image?

I plagiarized your list as a starting point :-) - Use 8GB SD card, install all required software on that card on Pi - Remove card from Pi and insert it into my desktop Pi's card reader - Use dd to create an ‘img’ file on the USB storage (HDD or thumb drive depending on which extra Pi I'm using) - Ru...

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