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by NotRequired
Wed Sep 18, 2019 5:26 pm
Forum: General discussion
Topic: Power over Ethernet and Fan
Replies: 9
Views: 185

Re: Power over Ethernet and Fan

You could use a linear voltage regulator (only recommended for smaller regulations, eg. 5V to 3.3V) or a buck converter (DC-to-DC, better for larger regulations, eg. 48V to 5V). If the fan is low wattage you could also use the regulators on the Pi and power it from the GPIO DC power pins (PIN1 and P...
by NotRequired
Thu May 17, 2018 12:41 pm
Forum: General discussion
Topic: rc.local python+pd
Replies: 9
Views: 804

Re: rc.local python+pd

@DougieLawson: Your systemd service is missing the "Type" (simple or oneshot probably) specifier, if the script is supposed to do some work and then exit, your service would run that task over and over (due to Restart=always). https://www.freedesktop.org/software/systemd/man/systemd.service.html ht...
by NotRequired
Wed May 16, 2018 10:19 am
Forum: General discussion
Topic: rc.local python+pd
Replies: 9
Views: 804

Re: rc.local python+pd

I think your problem is that you are loading the Pd patches in the GUI from the terminal. In order to load them without GUI, you apparently need to use "pd -nogui /path/to/file.pd". As for the python script, it may be loaded before the network is up. I do not think that it is a good idea to use rc.l...
by NotRequired
Sat Apr 14, 2018 6:14 pm
Forum: General discussion
Topic: USB-HDD not allow me to write. It wants to be Read only in EXT4 format
Replies: 23
Views: 2651

Re: USB-HDD not allow me to write. It wants to be Read only in EXT4 format

The drive is mounted with read only (ro) option. How exactly is the drive mounted?

/dev/sda1 on /mnt/USB1 type ext4 (ro,noatime,data=ordered)
by NotRequired
Sat Apr 14, 2018 2:47 pm
Forum: General discussion
Topic: USB-HDD not allow me to write. It wants to be Read only in EXT4 format
Replies: 23
Views: 2651

Re: USB-HDD not allow me to write. It wants to be Read only in EXT4 format

thagrol wrote:
Sat Apr 14, 2018 2:41 pm
NotRequired wrote:
Sat Apr 14, 2018 1:23 pm
The drive is created as SUDO, SUDO therefore owns the drive.
I think you'll find that's "root:root" not "SUDO, SUDO". Pedantiic? Maybe, but in technical matters precision is important.
Yes, it's owned by root and the second "sudo" in my post should probably have been "root" :)
by NotRequired
Sat Apr 14, 2018 1:23 pm
Forum: General discussion
Topic: USB-HDD not allow me to write. It wants to be Read only in EXT4 format
Replies: 23
Views: 2651

Re: USB-HDD not allow me to write. It wants to be Read only in EXT4 format

The drive is created with SUDO, ROOT therefore owns the drive. sudo chown -R 1000:1000 /mnt/my_hub "1000:1000" can be replaced with "pi:pi" :) EDIT: Another note, in your makefs command, you should declare how much space should be reserved for system (-m X) and how many inodes (-N X) should be creat...
by NotRequired
Thu Mar 22, 2018 6:19 pm
Forum: General discussion
Topic: Can I connect following sensors to Raspberry Pi?
Replies: 1
Views: 203

Re: Can I connect following sensors to Raspberry Pi?

Yes, you can connect the sensors to a Pi (source code for both sensors in the bottom of the links). Yes, you can log data to SD. Yes, you can communicate from PC to Pi. Yes, you can use C, Python and Java on the Pi.
by NotRequired
Fri Mar 16, 2018 6:53 pm
Forum: General discussion
Topic: In-Car Use: SD Corruption?
Replies: 14
Views: 1759

Re: In-Car Use: SD Corruption?

The Pi does not take any damage from power loss. Transients and/or voltage spikes will however almost certainly kill it in an instant. The SD card is the issue here but if you prepare it for read only operation and you keep a backup (as an image) of the SD card, corruption in the file system should ...
by NotRequired
Fri Mar 16, 2018 6:25 pm
Forum: General discussion
Topic: In-Car Use: SD Corruption?
Replies: 14
Views: 1759

Re: In-Car Use: SD Corruption?

A read only solution would lower the risk of data corruption significantly. However, this is not a guarantee that the SD card will survive power outages. Usually the corruption caused by power outages are only "file system related", meaning that a reformat will restore the cards functionality - but ...
by NotRequired
Thu Mar 15, 2018 12:43 pm
Forum: General discussion
Topic: In-Car Use: SD Corruption?
Replies: 14
Views: 1759

Re: In-Car Use: SD Corruption?

Power outages are bad for the SD card, no discussion about that. I did mention "stable 5v" and "can be an issue" about the car usage, and a clean shut down is required anywhere anyway so I assumed that was apparent. As long as the Pi draws power directly from the car battery (using a quality buck co...
by NotRequired
Thu Mar 15, 2018 11:49 am
Forum: General discussion
Topic: In-Car Use: SD Corruption?
Replies: 14
Views: 1759

Re: In-Car Use: SD Corruption?

As long as you can get stable 5v power for your Pi, you can (almost) use it anywhere and the SD card is no bigger concern in a car than it is in a wall plug. Getting stable voltage in a car can be an issue, though..
by NotRequired
Thu Mar 08, 2018 6:18 pm
Forum: Gaming
Topic: RetroPie controller
Replies: 4
Views: 1415

Re: RetroPie controller

If you do not want the "retro feel" from you controller, you could consider to get a Logitech F710 gamepad which is a great choice for both RetroPie and PC gaming :)
by NotRequired
Fri Feb 23, 2018 7:12 pm
Forum: General discussion
Topic: SD Cards & new rasberry pi
Replies: 7
Views: 975

Re: SD Cards & new rasberry pi

You could also consider to create a dual-boot setup using NOOBS where both raspbian OS and RetroPie OS is on the same SD card. During bootup you must then select which you want to load :)

EDIT: NOOBS and RetroPie are no good friends, apparently. Other options are available though :)
by NotRequired
Fri Feb 23, 2018 1:33 pm
Forum: General discussion
Topic: SD Cards & new rasberry pi
Replies: 7
Views: 975

Re: SD Cards & new rasberry pi

There is no problem in having multiple cards with multiple systems - but you cannot "hot swap" them. You should choose a Raspberry Pi 3 model B.
by NotRequired
Sat Jan 27, 2018 6:29 pm
Forum: General discussion
Topic: Using Hard Drive with Raspberry Pi
Replies: 46
Views: 30633

Re: Using Hard Drive with Raspberry Pi

I have not read all replies, so excuse if I repeat.. The Pi has a limitation in data transfer of 480Mbit/sec (60Mbyte/sec) due to the USB2 interface. I am not 100% sure, but this limitation may be shared with other parts of the Pi, so you should not expect a throughput (from USB to network) of 60MB/...
by NotRequired
Fri Jan 26, 2018 6:58 pm
Forum: General discussion
Topic: power supply questions
Replies: 23
Views: 1904

Re: power supply questions

Ummm.... No. Two points. First, power transistors can handle a lot more than 1A. Second, MOSFET is "Metal Oxide Semiconductor Field Effect Transistor". That is, a MOSFET is just a particular kind of transistor, not a different device. We cannot disagree on this, but I do not think my answer to OP i...
by NotRequired
Fri Jan 26, 2018 12:14 pm
Forum: General discussion
Topic: power supply questions
Replies: 23
Views: 1904

Re: power supply questions

I'll stand corrected; I've modified the previous post and for the future I'll use pressure as description of voltage when needed.

And as a side note: Water moving at 10km/h has higher pressure (or force to push) than water moving at 5km/h. In fact, A LOT more! ;)
by NotRequired
Thu Jan 25, 2018 7:12 pm
Forum: General discussion
Topic: power supply questions
Replies: 23
Views: 1904

Re: power supply questions

Heater wrote:
Thu Jan 25, 2018 6:56 pm
Please delete your water analogy. It is totally wrong.
It is not totally wrong, it was just a bit ill-formed and I have hereby corrected it :)
by NotRequired
Thu Jan 25, 2018 6:22 pm
Forum: General discussion
Topic: power supply questions
Replies: 23
Views: 1904

Re: power supply questions

Everyone needs to start somewhere, the analogy between water and electricity is not that stupid and it is used in educational books for basic electronics learning. @achrn: In this context, speed and pressure would be the same thing. Voltage is the penetration force (speed of water), current is the a...
by NotRequired
Thu Jan 25, 2018 2:36 pm
Forum: General discussion
Topic: power supply questions
Replies: 23
Views: 1904

Re: power supply questions

Think of electricity as being water moving around in pipes, where your power supply is the pump moving the water. Ampere is the amount of water circulating in the pipe(s) and voltage is the pressure of the water - watt is the power of the water in the pipe(s). When the pressure of the water (voltage...
by NotRequired
Tue Jan 16, 2018 6:38 pm
Forum: General discussion
Topic: Failing USB hard drive
Replies: 55
Views: 5447

Re: Failing USB hard drive

And I don't even have lsscsi: pi3# lsscsi -g -> bash: lsscsi: command not found What I'm thinking is that the Pi kernel, and uname -a shows me Linux pi3 4.9.72-v7+ #1069 SMP Fri Dec 29 17:21:52 GMT 2017 armv7l GNU/Linux is by nature meant to run on SD cards, it has no reason to have scsi or scsi em...
by NotRequired
Tue Jan 16, 2018 11:55 am
Forum: General discussion
Topic: Failing USB hard drive
Replies: 55
Views: 5447

Re: Failing USB hard drive

I'm not sure that you are supposed to mount /dev/sg* devices directly. They usually have a /dev/sdXY name also so try to run command "lsscsi -g" or try to "ls /dev/sd*" to see if the drive is to be found there. If you can find the "sdXY" name, try to mount that instead :)
by NotRequired
Mon Jan 15, 2018 6:58 pm
Forum: General discussion
Topic: Failing USB hard drive
Replies: 55
Views: 5447

Re: Failing USB hard drive

You need to post info about the exact drive model/type and how it is hooked up and powered (SATA to USB bridge, external enclosure etc.) in order to get real advices. Warning: You should not let the drive grind away in the hope that it will eventually start working! If this is related to a SATA to U...
by NotRequired
Sun Jan 14, 2018 12:07 pm
Forum: General discussion
Topic: Problems with Davfs2 - Secrets file
Replies: 5
Views: 1628

Re: Problems with Davfs2 - Secrets file

Great you got it solved :) Because you are mounting a network resource, you should add the "nofail" attribute to your fstab entry since this would let mount ignore errors and continue normal boot.
by NotRequired
Sat Jan 13, 2018 8:07 pm
Forum: General discussion
Topic: Serial data - hex values - convert to decimal values???
Replies: 3
Views: 944

Re: Serial data - hex values - convert to decimal values???

I cannot test the code, but this should read one "word" (two bytes) with the low byte first:

Code: Select all

def ReadWord():
  lb = serial.read()
  hb = serial.read()
  return (hb << 8) | lb

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