Go to advanced search

by TimG
Fri Jul 23, 2021 12:15 am
Forum: General discussion
Topic: SD Card power failure resilience ideas
Replies: 49
Views: 26218

Re: SD Card power failure resilience ideas

When you say its not bomb proof, is that with regards to the data in the home dir, but the read only data should be "bomb proof"? If you're worried, put the /home partition on a separate device and delete the /boot line from fstab. I still wouldn't say this is bomb-proof, since weird thin...
by TimG
Thu Jul 22, 2021 11:20 am
Forum: General discussion
Topic: SD Card power failure resilience ideas
Replies: 49
Views: 26218

Re: SD Card power failure resilience ideas

Is then any option for a none readonly file system (so one can store cookies), that is safe for power outages? Does the pi support `btrfs` or `f2fs`? You may run a read-write disk or partition alongside the read-only root. This doesn't protect the RW device from corruption, but it does allow the sy...
by TimG
Mon Apr 12, 2021 10:34 am
Forum: General discussion
Topic: How to reduce power consumption
Replies: 12
Views: 851

Re: How to reduce power consumption

If you don't need video output you can save ~90mW with

Code: Select all

/opt/vc/bin/tvservice -off
A Pi-zero (not a Zero-W) under light load consumes about 335mW. I don't know of any way to do better whilst running Linux, but many microcontrollers can run on far less power.
by TimG
Sun Nov 29, 2020 7:03 am
Forum: General discussion
Topic: Raspberry Pi Zero automatic safe shutdown
Replies: 78
Views: 3681

Re: Raspberry Pi Zero automatic safe shutdown

Would a read-only root filesystem be suitable in this project? It can avoid the need for a controlled shutdown completely. Any volatile data may be stored on a USB stick, or on a separate partition on the uSD card. In case the volatile partition is corrupted during power interruption, the Pi remains...
by TimG
Thu Oct 15, 2020 5:36 pm
Forum: General discussion
Topic: Looking for a sensor recommendation
Replies: 1
Views: 109

Re: Looking for a sensor recommendation

Do you want to measure speed, or just presence? Is the object's trajectory always the same?
by TimG
Sun Aug 30, 2020 9:39 pm
Forum: General discussion
Topic: Disable wifi but not bluetooth
Replies: 3
Views: 2684

Disable wifi but not bluetooth

I wanted to disable WiFi on my Pi3+ with dtoverlay=disable-wifi in /boot/config.txt, but this had the effect of also disabling Bluetooth. Is this normal behaviour? The same config on my Pi4 disables WiFi only. Is there a recommended way to disable WiFi but keep Bluetooth active? Running latest Raspi...
by TimG
Tue Aug 04, 2020 8:12 pm
Forum: General discussion
Topic: ARE THE HIGH QUALITY SENSORS FOR RPi?
Replies: 9
Views: 700

Re: ARE THE HIGH QUALITY SENSORS FOR RPi?

I wonder if you guys have suggestions on where to source high quality for the RPi, with which decent and reliable measurements can be made Take a look at the Qwiic system from Sparkfun: https://www.sparkfun.com/qwiic They make good quality boards which can be connected with cables, rather than sitt...
by TimG
Sun Jul 05, 2020 11:51 am
Forum: General discussion
Topic: Please improve the sound quality of the Raspberry Pi product.
Replies: 28
Views: 2331

Re: Please improve the sound quality of the Raspberry Pi product.

to get the best audio experience with the RPi one needs to invest on I2S DAC. there are so many in the market. Pimoroni used to make a very good audio DAC for UKP 7.50, but it seems to have been discontinued. The nearest equivalent I can find is from Adafruit: https://www.adafruit.com/product/4037 ...
by TimG
Sat Feb 15, 2020 4:45 pm
Forum: General discussion
Topic: STRANGE -- make changes - reboot - changes are gone!???
Replies: 10
Views: 1237

Re: STRANGE -- make changes - reboot - changes are gone!???

Here's a little script that my Pis run daily. It tests the filesystem, looks for kernel errors, and sends a warning email if anything is wrong. #!/bin/bash # email parameters email="sendEmail -f me@mail.com -t me@mail.com -s smtp.mail.com:587 -o tls=yes -xu username -xp password -q" subj=&...
by TimG
Sat Feb 15, 2020 3:30 pm
Forum: General discussion
Topic: STRANGE -- make changes - reboot - changes are gone!???
Replies: 10
Views: 1237

Re: STRANGE -- make changes - reboot - changes are gone!???

Did you toggle read-only mode in the rpi config program or another way? Another possibility is that the SD card is damaged and has turned read-only. I’ve had a couple of memory cards do this after a power brown-out. It’s not immediately obvious because no errors are generated, and as long as the ne...
by TimG
Tue Jan 14, 2020 9:58 pm
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 50418

Re: Future of raspberry pi

Remember, I said software work, not hardware. Hardware requests just get into a mess, but it would be interesting to know where people think the software needs work. It would be fantastic to see somebody pick up development of the WiringPi library. Of all the various GPIO libraries, WiringPi was es...
by TimG
Fri Nov 22, 2019 9:35 pm
Forum: Raspberry Pi OS
Topic: Readonly Root with OverlyFS
Replies: 45
Views: 28357

Re: Readonly Root with OverlyFS

[...] And that's it. You are executing things on a rw version of the root, so you can apt update & upgrade normally You can receive some warnings about unable to communicate with systemd, but I found that are normally non fatal. This is great! I haven't tried it yet, but I certainly will soon. ...
by TimG
Mon Oct 28, 2019 2:00 pm
Forum: General discussion
Topic: What does it take for the Pi 4B to reach 3A power consumption?
Replies: 7
Views: 1410

Re: What does it take for the Pi 4B to reach 3A power consumption?

Your meter doesn't show you the very short (millisseconds) current peaks that may happen. Absolutely. When I measured a Pi2 it drew a 1 millisecond current spike of 700mA during boot. USB peripherals may do the same. These load spikes can cause cumulative damage to power supplies. Some supplies hav...
by TimG
Sun Oct 20, 2019 11:33 am
Forum: General discussion
Topic: Battery Level Indicator -- While Charging
Replies: 17
Views: 5062

Re: Battery Level Indicator -- While Charging

Most LiPo chargers have a charging status indicator. It won’t tell you what the charge level is, only when charging is complete. The detection is done by voltage levels: as the cell approaches it’s maximum voltage the charging current is reduced and then stopped at around 4.2V. More sophisticated ch...
by TimG
Fri Oct 11, 2019 2:07 am
Forum: General discussion
Topic: How can I monitor power supplied to my Pi 4B?
Replies: 15
Views: 5673

Re: How can I monitor power supplied to my Pi 4B?

This works well and monitors both current and voltage: https://www.adafruit.com/product/904 With earlier Pis I desoldered the main polyfuse and used the pads to wire in the INA219 board. It looks to me as though the Pi4 can’t be modified in this way, so the monitor circuit needs to be spliced into t...
by TimG
Mon Oct 07, 2019 12:21 pm
Forum: General discussion
Topic: Real time data acquisition and graphing using arduino and Raspberry pi
Replies: 7
Views: 726

Re: Real time data acquisition and graphing using arduino and Raspberry pi

There are 3 parts to this: Electronic interface: Do you have something already which can read out mains AC? Data acquisition: It sounds like you’re trying to get the phase relationship between current and voltage, so a fairly high sampling frequency will be needed. Something like this might be suita...
by TimG
Tue Sep 24, 2019 8:29 am
Forum: Troubleshooting
Topic: PIR motion sensor always outputting
Replies: 1
Views: 318

Re: PIR motion sensor always outputting

Daniel, can you post a clear and well-lit photo of your wiring, and a link to the datasheet of your PIR sensor?
Is the false detection literally continuous, or just frequent?
by TimG
Mon Sep 16, 2019 11:58 pm
Forum: Troubleshooting
Topic: sshfs causes pcmanfm to go berserk
Replies: 0
Views: 280

sshfs causes pcmanfm to go berserk

It seems that any failed sshfs connection, with a mount-point inside the user's home directory, will cause pcmanfm to go berserk and load the CPU 100% Steps to reproduce with latest Raspbian/Debian Buster: After logging-in to the gui, run sudo apt-get update sudo apt-get install sshfs mkdir ~/tmp ss...
by TimG
Thu Aug 29, 2019 6:41 pm
Forum: General discussion
Topic: raspberrypi-ui-mods
Replies: 4
Views: 13430

Re: raspberrypi-ui-mods

Ah-ha! Yes. In /var/log/lightdm/x-0.log Fatal server error: (EE) no screens found(EE) Adding hdmi_force_hotplug=1 to /boot/config.txt seems to have solved the problem. The Pi4 is running headless, and will be accessed via VNC. I don't remember that being needed on a Pi3+ with Stretch. I assume it's ...
by TimG
Thu Aug 29, 2019 6:09 pm
Forum: General discussion
Topic: raspberrypi-ui-mods
Replies: 4
Views: 13430

raspberrypi-ui-mods

It used to be possible to add the desktop environment to raspbian-lite by installing a single package (and all its dependencies): apt-get install raspberrypi-ui-mods This does not seem to be working on a Pi4 with 2019-07-10-raspbian-buster-lite.img. After running raspi-config and choosing "B4 D...
by TimG
Wed Aug 07, 2019 4:49 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 273
Views: 54726

Re: Why moving to 64bit?

piglet wrote:
Wed Aug 07, 2019 11:56 am
jamesh wrote:
Tue Aug 06, 2019 2:44 pm
although we are learning by osmosis.
*cough* diffusion is the closer analogy, unless you've a semi-permeable membrane in the office for the information to pass through *cough*
The skull is semi-permeable to information. At least, some are.
by TimG
Mon Jul 08, 2019 11:22 pm
Forum: General discussion
Topic: Power Supply for multiple RAPI4B+
Replies: 45
Views: 29408

Re: Power Supply for multiple RAPI4B+

The official RPi power supply is actually hard to beat on price and reliability. There are industrial power supplies which would be more compact, but good ones aren't cheap -- especially once you factor in cabling, connectors, and a ventilated case. Cheaper power supplies are the cause of endless di...
by TimG
Tue Jul 02, 2019 6:33 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 947
Views: 224015

Re: Raspberry Pi 4 Thread - general discussion

Just a guess, but it looks to me like the extra componentry there is related to the USB hub. On closer examination it looks like the power circuitry is for the VIA chip and SOC. I guess the main power chip does not generate all the necessary voltage levels. That still leaves the two 8-pin chips nea...
by TimG
Mon Jul 01, 2019 11:45 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 947
Views: 224015

Re: Raspberry Pi 4 Thread - general discussion

Purely out of curiosity, what are the Pi4's extra components around the audio jack? PWM drivers and a stabilised power supply? How is the Pi4's audio quality compared to previous models?

LHS: Pi3B+
RHS: Pi4
pijacksmall.jpg
pijacksmall.jpg (155.48 KiB) Viewed 4044 times
by TimG
Sun Jun 30, 2019 4:58 pm
Forum: General discussion
Topic: Bluetooth audio glitches (with Pi-3 only)
Replies: 1
Views: 641

Re: Bluetooth audio glitches (with Pi-3 only)

I noticed (systemctl status hciuart) that the bluetooth communication is 3Mbps (with flow-control) on the 3B+, but only 0.92Mbps (without flow-control) on the 3B. Both should be sufficient for an A2DP audio stream, but it's the only difference I could spot. Anyway, now that Buster is out (*before* D...

Go to advanced search