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by jdb
Mon Dec 09, 2019 9:06 pm
Forum: General discussion
Topic: How does the Raspberry Pi work?
Replies: 17
Views: 270

Re: How does the Raspberry Pi work?

kenkrsme wrote:
Mon Dec 09, 2019 5:56 pm
magic
Precisely the wrong answer.

Also, because this is effectively a dupe thread and cogent responses have been posted here: thread locked.
by jdb
Thu Dec 05, 2019 7:38 pm
Forum: Advanced users
Topic: VL805 firmware release 0137ac - improved USB downstream power switching
Replies: 14
Views: 839

Re: VL805 firmware release 0137ac - improved USB downstream power switching

All looks good. But according to my POE port, the same power is delivered before and after, in my case 3,5 watt What do you have plugged into the USB ports? It goes without saying that you won't notice any device power savings unless you have devices in your USB ports... The 2. patching does not wo...
by jdb
Thu Dec 05, 2019 1:56 pm
Forum: Troubleshooting
Topic: Pi 4 4GB- Wifi not working when resolution is set too high
Replies: 63
Views: 4641

Re: Pi 4 4GB- Wifi not working when resolution is set too high

Remove the file /boot/.firmware_revision.
by jdb
Wed Dec 04, 2019 8:27 pm
Forum: Advanced users
Topic: VL805 firmware release 0137ac - improved USB downstream power switching
Replies: 14
Views: 839

VL805 firmware release 0137ac - improved USB downstream power switching

We've received an updated firmware from VLI that allows for port power control, i.e. turning off downstream USB devices. The attached zip file contains an updated firmware and patch file. Note: rebooting is required after flashing the new firmware. Step 1: Flash the firmware to the VLI EEPROM: # if ...
by jdb
Wed Dec 04, 2019 1:28 pm
Forum: Bare metal, Assembly language
Topic: Pointer to BCM2835 counters - A nightmare
Replies: 5
Views: 206

Re: Pointer to BCM2835 counters - A nightmare

The reason the free-running timer doesn't show up on your Pi 3's iomem ranges is because the default timing source is the ARM architectural timer. Each CPU has a local timer fed from the oscillator clock (19.2MHz on BCM283x). The STC peripheral (Videocore's timer) isn't used with Pi models >=2. As y...
by jdb
Tue Dec 03, 2019 10:35 pm
Forum: General discussion
Topic: Pi 4 Wasn't Booting. Here is my fix. (inserting the sd-card)
Replies: 52
Views: 1263

Re: Pi 4 Wasn't Booting. Here is my fix. (inserting the sd-card)

On second thoughts, I'm locking this thread lest it collapse into another round of "blame the user". I'm also going to bring this to the attention of the web team and whoever does the packaging. @averageyouzer if you want to make another post in this thread, please click the "report message" button ...
by jdb
Tue Dec 03, 2019 10:25 pm
Forum: General discussion
Topic: Pi 4 Wasn't Booting. Here is my fix. (inserting the sd-card)
Replies: 52
Views: 1263

Re: Pi 4 Wasn't Booting. Here is my fix.

That URL isn't a link to the setup guide. It hits the landing page for Raspberry Pi, and front and centre is the blog (which is by design). You have to go through 2 clicks to get to the generic setup guide (Raspberry Pi 4 splash -> find out more -> get started). Alternatively the banner menu: "Help...
by jdb
Tue Dec 03, 2019 8:39 pm
Forum: General discussion
Topic: Pi 4 Wasn't Booting. Here is my fix. (inserting the sd-card)
Replies: 52
Views: 1263

Re: Pi 4 Wasn't Booting. Here is my fix.

When I got my (pre-release) retail packaged Pi 4, there was a small pictographic card slip along with the regulatory information leaflet inside the box. I assume it's pictographic to avoid translating into dozens of languages, but that card slip needs to have URLs on it somewhere. It already does !...
by jdb
Tue Dec 03, 2019 8:14 pm
Forum: General discussion
Topic: Pi 4 Wasn't Booting. Here is my fix. (inserting the sd-card)
Replies: 52
Views: 1263

Re: Pi 4 Wasn't Booting. Here is my fix.

The issue here is booting off USB. As pointed out earlier it would have worked just fine without an SD Card for a 3B+ and for a 3B after a one time boot from SD Card to set the 'boot from USB' option. {...} If the OP had used a 3B+ or waited a few months for 4B firmware to be updated they'd have be...
by jdb
Tue Dec 03, 2019 8:06 pm
Forum: General discussion
Topic: Pi 4 Wasn't Booting. Here is my fix. (inserting the sd-card)
Replies: 52
Views: 1263

Re: Pi 4 Wasn't Booting. Here is my fix.

Well the documentation I received with my unit did not mention it. I however did not think to look for the official documentation. It may have been clear to ya'll and that is fabulous but I was just trying to help other users that may be having issues. That is all. Out of the millions upon millions...
by jdb
Sat Nov 30, 2019 4:05 pm
Forum: General discussion
Topic: Raspberry Pi 4 hardware init time
Replies: 3
Views: 243

Re: Raspberry Pi 4 hardware init time

Is there any improvement if you load the cutdown firmware? start_cd=1 in config.txt. ~3MB loaded from the SD card -> 700KB.

Also add initial_turbo=30 to force the ARM cores to boot at max speed for the first 30 seconds.
by jdb
Thu Nov 28, 2019 6:08 pm
Forum: Troubleshooting
Topic: Rasperry-pi 4 Wi-fi connection problems
Replies: 2
Views: 310

Re: Rasperry-pi 4 Wi-fi connection problems

The RPi4 has Wifi problems. See e.g.: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=254640 or https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=247405 You're linking to two completely unrelated issues. The OP even said that he managed to download Raspbian over wireless using NOOBS, ...
by jdb
Wed Nov 27, 2019 2:47 pm
Forum: Troubleshooting
Topic: I want to know how to reduce the noise of Raspberrypi 3B +
Replies: 18
Views: 520

Re: I want to know how to reduce the noise of Raspberrypi 3B +

Edit: LTolledo isn't the op... Thank you for your reply. The noise did not change even when switching with amixer cset numid = 3 x. The noise did not change even when power was supplied to the Pi from the phone battery charger. The output volume is set with alsamixer. What is the output volume set t...
by jdb
Sun Nov 24, 2019 1:36 pm
Forum: Troubleshooting
Topic: I want to know how to reduce the noise of Raspberrypi 3B +
Replies: 18
Views: 520

Re: I want to know how to reduce the noise of Raspberrypi 3B +

Thank you for your reply. Since the amplifier is DC12V for cars, it cannot be supplied with a mobile phone charger. Currently, the AC → DC12V conversion adapter is used. Even if the conversion adapter is from another manufacturer, the noise is the same. Moreover, the noise is the same even if anoth...
by jdb
Sun Nov 24, 2019 1:55 am
Forum: Troubleshooting
Topic: I want to know how to reduce the noise of Raspberrypi 3B +
Replies: 18
Views: 520

Re: I want to know how to reduce the noise of Raspberrypi 3B +

am more interested to know what amplifier the OP is using in my past experience with this phenomenon, there are some amplifiers that are more susceptible to "noise". I have two of those...not connected anymore to any RPi system. a PAM8403 based amplifier seems to do away with most noise on a shared...
by jdb
Sat Nov 23, 2019 9:05 pm
Forum: Advanced users
Topic: DVFS Firmware
Replies: 58
Views: 5074

Re: DVFS Firmware

I didn't use rpi-update because this came with a thirdparty kinda-bleeding edge distribution (namely Manjaro ARM). So i knew and accepted the risk of things breaking. Welp, it's broken - so why are you requesting support on our forums for a third-party distribution? This question is orthogonal to w...
by jdb
Sat Nov 23, 2019 8:23 pm
Forum: Advanced users
Topic: DVFS Firmware
Replies: 58
Views: 5074

Re: DVFS Firmware

Are they non-standard? Yes of course but this has no relevance here because this new firmware is unnecessarily limiting functionality/capabilities which were working previously. If you/the dev team don't want to fix this "issue" just include a config option to revert to old behavior for power users...
by jdb
Sat Nov 23, 2019 5:10 pm
Forum: Troubleshooting
Topic: I want to know how to reduce the noise of Raspberrypi 3B +
Replies: 18
Views: 520

Re: I want to know how to reduce the noise of Raspberrypi 3B +

Does the noise change at all if you put audio_pwm_mode=1 in /boot/config.txt?
by jdb
Sat Nov 23, 2019 1:20 pm
Forum: Troubleshooting
Topic: I want to know how to reduce the noise of Raspberrypi 3B +
Replies: 18
Views: 520

Re: I want to know how to reduce the noise of Raspberrypi 3B +

What does the noise sound like?
by jdb
Thu Nov 21, 2019 8:32 pm
Forum: Advanced users
Topic: How to hw-disable the Raspbery Pi-4 Wlan-/Sd-Card Controller CYW 43455 (aka BCM43438)
Replies: 29
Views: 1135

Re: How to hw-disable the Raspbery Pi-4 Wlan-/Sd-Card Controller CYW 43455 (aka BCM43438)

Well, I see your points. And yes, maybe the Intel-ME has made us all paranoids. well, no, not really - because the US government saw that intel ME was a security threat and made Intel put in an undocumented disable bit, which was subsequently found out However, the best way to clear security concer...
by jdb
Thu Nov 21, 2019 6:36 pm
Forum: Advanced users
Topic: RPi4 - Power Savings
Replies: 32
Views: 1831

Re: RPi4 - Power Savings

One more. Now comes the ethernet port. That one behaves quite differently. All I figured so far is turning it on/off, or perhaps better would be saying putting it to idle and activate it, relates to: plug or unplug a cable Unfortunately there is NO overlay called "disable-ethernet". Below my tests....
by jdb
Thu Nov 21, 2019 5:10 pm
Forum: Advanced users
Topic: DVFS Firmware
Replies: 58
Views: 5074

Re: DVFS Firmware

I'm giving it a try. I don't stress my Pi 4B much, but I'll see how it holds up anyway. Partially-busy workloads are likely to see the most benefit - the intermediate performance point at 1GHz doesn't need as much volts as 1.5GHz, so "busy" temperatures should be closer to idle temperatures (and id...
by jdb
Wed Nov 20, 2019 5:15 pm
Forum: Troubleshooting
Topic: RPI 4: USB Wireless Kbd/Mouse requires hot-pluging to start working after booting
Replies: 19
Views: 485

Re: RPI 4: USB Wireless Kbd/Mouse requires hot-pluging to start working after booting

No idea. I have one on my desk that does exactly the same thing - and the analyzer doesn't report anything going obviously wrong, just that the device never responds to any setup packets after a reboot. Some mechanism by which we're cycling power to the downstream ports over a reboot is causing the ...
by jdb
Wed Nov 20, 2019 4:44 pm
Forum: Troubleshooting
Topic: RPI 4: USB Wireless Kbd/Mouse requires hot-pluging to start working after booting
Replies: 19
Views: 485

Re: RPI 4: USB Wireless Kbd/Mouse requires hot-pluging to start working after booting

Does it work if you insert a hub between the keyboard dongle and the Pi 4?

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