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by jdb
Sat Nov 16, 2019 8:14 pm
Forum: General discussion
Topic: Interview with Eben Upton
Replies: 8
Views: 237

Re: Interview with Eben Upton

Yup that's an interview with "Mr Raspberry Pi" This made me think, is the Pi foundation a publicly traded company? If so what's their stock ticker? Raspberry Pi (trading) ltd. is a private limited company in the UK that has a single 100% shareholder - the Raspberry Pi Foundation. The Raspberry Pi F...
by jdb
Fri Nov 15, 2019 6:51 pm
Forum: General discussion
Topic: Pi4 as Desktop computer
Replies: 267
Views: 24371

Re: Pi4 as Desktop computer

@moderator, Hey, what's with the deleting the Facebook bashing? The despicable behavior of FB deserves to be pointed out at every opportunity. Young users of the Pi deserve being made aware of how internet giants abuse us. Isn't such computer literacy education part of the mission of the Pi Foundat...
by jdb
Fri Nov 15, 2019 10:39 am
Forum: Troubleshooting
Topic: Who can tell? When will the proprietary driver for VC6 appear?
Replies: 8
Views: 245

Re: Who can tell? When will the proprietary driver for VC6 appear?

Never. The KMS driver is the only one that exists for VC6 as used on Pi 4.

Also, define "very poor". In comparison to what? Using what program?
by jdb
Thu Nov 14, 2019 10:14 pm
Forum: General discussion
Topic: Storage-addressing limits on 4GB Raspberry Pi 4 Model B?
Replies: 8
Views: 331

Re: Storage-addressing limits on 4GB Raspberry Pi 4 Model B?

There is no hardware reason why the Pi4B cannot address a maximum-size ext4 filesystem. Or any previous Pi, for that matter.
by jdb
Thu Nov 14, 2019 1:59 pm
Forum: General discussion
Topic: GPIO Pins not seated properly
Replies: 12
Views: 365

Re: GPIO Pins not seated properly

Thanks. We'll investigate.
by jdb
Thu Nov 14, 2019 11:17 am
Forum: General discussion
Topic: GPIO Pins not seated properly
Replies: 12
Views: 365

Re: GPIO Pins not seated properly

That type of error should be pretty easy to catch with automated inspection, even a simple dimension check would have failed with the header sticking up that far. Every Pi goes through automated optical inspection at each stage of the soldering process. There's no way that this got through those. @...
by jdb
Tue Nov 12, 2019 10:39 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM peripheral bus error
Replies: 14
Views: 318

Re: PWM peripheral bus error

Reads either stall the access bus or (more likely) just sample the PWM domain signal and provide a slightly delayed version of it. The consequence of the second implementation is that you can write a register and read it back immediately, but you will get stale data in the read. If the bus is stalle...
by jdb
Mon Nov 11, 2019 5:03 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM peripheral bus error
Replies: 14
Views: 318

Re: PWM peripheral bus error

Synchronisation of register writes usually requires a handshake type interface, where a write in the system clock domain crosses into the PWM clock domain and is acknowledged. A 300uS sleep being neccessary between writes to PWMCTL implies you are driving a slow clock into PWM. This is interesting ...
by jdb
Fri Nov 08, 2019 2:58 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM peripheral bus error
Replies: 14
Views: 318

Re: PWM peripheral bus error

That code doesn't set up the clock to the PWM peripheral. If the clock is not running, you won't get any output at all. As far as I know, the firmware won't touch the PWM clock unless you request onboard audio output, at which point it would get initialised at 100MHz - far too fast for a stepper mot...
by jdb
Fri Nov 08, 2019 11:29 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM peripheral bus error
Replies: 14
Views: 318

Re: PWM peripheral bus error

Please post the full code you are using to drive the PWM peripheral.
by jdb
Thu Nov 07, 2019 4:37 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM peripheral bus error
Replies: 14
Views: 318

Re: PWM peripheral bus error

What clock speed are you using to drive the PWM peripheral? I would imagine stepper motors are driven at kHz rates.
by jdb
Wed Nov 06, 2019 1:47 pm
Forum: General discussion
Topic: Interesting interview with Eben in Physics World
Replies: 41
Views: 1480

Re: Interesting interview with Eben in Physics World

Burngate wrote:
Wed Nov 06, 2019 11:59 am

Seems slightly incestuous - or maybe keeping the business within the family
The term is "dogfooding". And why not? Use Pis to bring down the cost of building Pis?
by jdb
Tue Nov 05, 2019 1:21 pm
Forum: Troubleshooting
Topic: VLI firmware v2.0 - powersaving features enabled
Replies: 102
Views: 13878

Re: VLI firmware v2.0 - powersaving features enabled

Does the same temperature rise happen with no USB devices plugged in?
by jdb
Tue Nov 05, 2019 1:20 pm
Forum: Compute Module
Topic: USB 2.0 Dropped frames
Replies: 25
Views: 3062

Re: USB 2.0 Dropped frames

Responded via email.
by jdb
Tue Nov 05, 2019 10:56 am
Forum: Troubleshooting
Topic: VLI firmware v2.0 - powersaving features enabled
Replies: 102
Views: 13878

Re: VLI firmware v2.0 - powersaving features enabled

Troubleshooting noname USB webcams isn't going to be possible - unless there's a generic issue with the transport protocol in question. Command output stdout+stderr That's not the output of the lspci command. It does however confirm that both cameras are UVC compliant devices so it should be reprodu...
by jdb
Tue Nov 05, 2019 10:48 am
Forum: Troubleshooting
Topic: RPi4B throttling > 40C
Replies: 8
Views: 305

Re: RPi4B throttling > 40C

Your CPU isn't being thermally throttled. The clock speed is being reduced due to the ondemand cpufreq governor.
https://www.kernel.org/doc/Documentatio ... ernors.txt
by jdb
Mon Nov 04, 2019 11:46 am
Forum: Troubleshooting
Topic: VLI firmware v2.0 - powersaving features enabled
Replies: 102
Views: 13878

Re: VLI firmware v2.0 - powersaving features enabled

In the case where it goes wrong, there are multiple successful transfers from both cameras and then it seems to fall apart: <idle>-0 [000] d.h. 308.914257: xhci_handle_event: EVENT: TRB 000000001edc4890 status 'Short Packet' len 3060 slot 3 ep 3 type 'Transfer Event' flags e:c <idle>-0 [000] d.h. 30...
by jdb
Mon Nov 04, 2019 9:50 am
Forum: Troubleshooting
Topic: VLI firmware v2.0 - powersaving features enabled
Replies: 102
Views: 13878

Re: VLI firmware v2.0 - powersaving features enabled

Which model of webcam(s) do the traces correspond to?

Edit: the second trace only has a single active endpoint transferring data. Are both cameras being used/working?

Edit2: github truncated the trace. The raw download is complete.
by jdb
Sat Nov 02, 2019 7:55 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPi4 + Purethermal 2 USB problem
Replies: 8
Views: 1649

Re: RPi4 + Purethermal 2 USB problem

Known issue.

Workaround in the PureThermal firmware here:
https://github.com/groupgets/puretherma ... -524177762
by jdb
Sat Nov 02, 2019 7:41 pm
Forum: Troubleshooting
Topic: VLI firmware v2.0 - powersaving features enabled
Replies: 102
Views: 13878

Re: VLI firmware v2.0 - powersaving features enabled

Wierd. I would expect performance degradation (in the off-chance we've not explored some set of wakeup latency/servicing interval required by the cams) and not a complete failure. Can you capture an xhci debug trace? sudo -s cd /sys/kernel/debug/tracing echo 1 > events/xhci-hcd/enable [Plug device(s...
by jdb
Sat Nov 02, 2019 7:29 pm
Forum: General discussion
Topic: Resistor and Capacitors damaged on raspberry pi 3 model B
Replies: 3
Views: 371

Re: Resistor and Capacitors damaged on raspberry pi 3 model B

This is a troll post. - Components do not "fall off" the board if you wipe it with a cloth, unless your cloth is made of sandpaper - "please give me the values of all the components on the board" - but you only knocked some off? - I fail to see how you could lose "all" the components on the ground, ...
by jdb
Fri Nov 01, 2019 4:07 pm
Forum: Troubleshooting
Topic: Raspberry pi 4b peripherals still powered on after shutdown
Replies: 9
Views: 668

Re: Raspberry pi 4b peripherals still powered on after shutdown

You need to also set WAKE_ON_GPIO=0. WAKE_ON_GPIO=1 implies POWER_OFF_ON_HALT=0, as detailed in the documentation.
by jdb
Thu Oct 24, 2019 7:33 pm
Forum: General discussion
Topic: Timeframe for USB C power board revision
Replies: 39
Views: 4146

Re: Timeframe for USB C power board revision

But we are flogging a dead horse. The issue is understood and there are simple workarounds... The only thing left folks can bitch about is the lack of timeframe. Which, in a roundabout way, validates my original point. Timeframe/availability information is a necessary input for any company wanting ...
by jdb
Thu Oct 24, 2019 2:52 pm
Forum: General discussion
Topic: How many devices can be connected to RPI4 ?
Replies: 4
Views: 248

Re: How many devices can be connected to RPI4 ?

The information is derived from the controller parameters registers: [email protected]:/sys/kernel/debug/usb/xhci/0000:01:00.0# cat reg-cap CAPLENGTH = 0x01000020 HCSPARAMS1 = 0x05000420 HCSPARAMS2 = 0xfc000031 HCSPARAMS3 = 0x00e70004 HCCPARAMS1 = 0x002841eb DOORBELLOFF = 0x00000100 RUNTIMEOFF = 0x00...
by jdb
Thu Oct 24, 2019 2:07 pm
Forum: General discussion
Topic: How many devices can be connected to RPI4 ?
Replies: 4
Views: 248

Re: How many devices can be connected to RPI4 ?

There is a limit of 30 simultaneously connected devices on Pi 4 - the hardware supports 32 device address slots but one address is kept free for unconfigured devices and one address is reserved by the internal USB2.0 hub for the USB2.0 ports. All USB3.0 hubs will work with Pi 4, but beware badly des...

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