Raspberry Pi Forums

TimG

[...] 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. Do y...

TimG

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...

TimG

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...

TimG

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...

TimG

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...

TimG

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?

TimG

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...

TimG

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 ...

TimG

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 Deskto...

TimG

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.

TimG

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...

TimG

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...

TimG

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 (155.48 KiB) Viewed 1600 times

TimG

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...

TimG

As the WiFi is just a module, I assume it is still fine for RS/Farnell to have orders for customised Pi4 without the WiFi/BT module there. Cutting the antenna trace would be sufficient, shirley? And/or a solder blob shorting it to ground. No, I'm not going to try it on my soon-to-arrive Pi4. Bravo ...

TimG

Here's a couple of useful links: https://designercircuits.com/DesignNote1c.pdf https://hackaday.com/2017/04/04/the-shocking-truth-about-transformerless-power-supplies/ Even though you need very little power, you do need mains-rated fail-safe components. It's usually cheaper and easier to find a disu...

TimG

Hi Everybody, I have set up a Pi as a bluetooth speaker, and I'm getting prominent audio glitches every few seconds. The odd thing is it *only* happens with a Pi-3B using the built-in bluetooth. Other Pi models are not affected. Does anybody know if this can be cured? A Pi-3B+ and the *same* uSD car...

TimG

Re. power: To avoid putting mains power in a box exposed to the weather, I've used an old 18V laptop power supply in combination with a small regulator like these: https://www.tracopower.com/products/browse-by-category/detail/dc-dc-converters/non-isolated-step-down-regulators/ The 18V supply (the ex...

TimG

Does anybody know if the camera ribbon cable can withstand soldering? I'd like to join a PiZero-to-camera adapter cable to a normal cable without using extra intermediate connectors. https://cdn.shopify.com/s/files/1/0174/1800/products/Camera_cable_1_of_3_19028afc-2f5f-40ba-863d-293ee88ef649_256x256...

TimG

A digital light detector would save you a lot of work. For example, https://www.adafruit.com/product/4162 https://cdn-learn.adafruit.com/assets/assets/000/073/757/small240/adafruit_products_VEML7700TopHeader.jpg On the other hand if you want to learn about phototransistors, here are a couple of usef...

TimG

It's been a while since I worked on fast-booting, but on a Pi Zero it's possible to start running code within 2 - 2.5 seconds. I used a systemd service file to launch my script as early as possible, like this: # example.service # run as early as possible [Unit] Description=Example Service DefaultDep...

TimG

- The LM386 has two audio inputs: inverting and non-inverting. Are they both connected to something? - The speaker output needs a DC-blocking capacitor. - Likely the USB headphone output needs a load. Connect a set of headphones in parallel. If you still get distortion, you may need DC-blocking capa...

TimG

Wow, thanks for the fix, and the build instructions. The updated binary has been running for an hour now with no glitches. Not having to monitor raspistill is going to simplify my code a lot.

TimG

Ah-ha. Yes, I just realised that my crashes are happening every 2^31 us.

$ raspistill -v
"raspistill" Camera App (commit 7cbfbd38d982 Tainted)

TimG

Hi everybody, Running raspistill in timelapse mode I'm encountering freezes and unexpected exits. These happen very regularly, and one of the following always seem to happen (in fact they alternate): - The raspistill process freezes and has to be killed. - The raspistill process gives an error like ...

Search found 294 matches

Re: Readonly Root with OverlyFS

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

Re: Battery Level Indicator -- While Charging

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

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

Re: PIR motion sensor always outputting

sshfs causes pcmanfm to go berserk

Re: raspberrypi-ui-mods

raspberrypi-ui-mods

Re: Why moving to 64bit?

Re: Power Supply for multiple RAPI4B+

Re: Raspberry Pi 4 Thread - general discussion

Re: Raspberry Pi 4 Thread - general discussion

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

Re: Raspberry Pi 4 Thread - general discussion

Re: Simple circuit to step down 120VAC

Bluetooth audio glitches (with Pi-3 only)

Re: Running an RPI outside?

Soldering camera cable

Re: light detector with photo transistor

Re: Fast boot on Pi-Zero with C library and GPIO access

Re: LM386 Audio Amp Module Producing buzzing/cracking noise

Re: raspistill crashes every 35 minutes

Re: raspistill crashes every 35 minutes

raspistill crashes every 35 minutes