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by MikeDB
Fri Oct 18, 2019 8:26 am
Forum: Bare metal, Assembly language
Topic: Pi 4 Bare Metal WiFi ?
Replies: 2
Views: 110

Re: Pi 4 Bare Metal WiFi ?

Gavinmc42 wrote:
Fri Oct 18, 2019 1:29 am
No.
Yes.
Pass.

Garry and team at Ultibo might be the closest?
My understanding is just the WiFi secuity software alone is a massive undertaking.
Okay thanks. About to respin a PCB and wondering whether to put one of the ESP8266 modules on it or not.
by MikeDB
Thu Oct 17, 2019 10:39 pm
Forum: Bare metal, Assembly language
Topic: Pi 4 Bare Metal WiFi ?
Replies: 2
Views: 110

Pi 4 Bare Metal WiFi ?

Does anyone have this working, or any hope of getting it working ?

Or is there some fundamental roadblock such as lack of documentation ?
by MikeDB
Wed Oct 16, 2019 1:01 pm
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

If your monitor currently works in Raspbian, then it is likely to be a combination of the kernel + RPi boot firmware versions causing the flashing issues you experienced. Both have been going through a rapid evolution since the RPi4 was launched. You can bring both up-to-date on Gentoo as follows: ...
by MikeDB
Wed Oct 16, 2019 9:53 am
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

On Gentoo64 I have the reverse problem, compiling for 32bit Pi's on Aarch64. Using Buildroot was the first thing that worked for me. Native Arm compiling? Run 32bit compilers on 32bit OS, run 64bit on 64bit OS, that works. Gentoo64 was actually my first port of call for going to 64 bits, but it did...
by MikeDB
Tue Oct 15, 2019 10:51 pm
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

There is https://packages.debian.org/buster/gcc-8-aarch64-linux-gnu however on the bottom it shows that it is availablle only for some limited set of architectures including i386 and ppc64el (!), it does not include armhf. Yes. I would have expected to be able to find something suitable on https://...
by MikeDB
Tue Oct 15, 2019 10:30 pm
Forum: Advanced users
Topic: Inter-core communication
Replies: 3
Views: 406

Re: Inter-core communication

tului wrote:
Tue Oct 15, 2019 10:15 am
http://man7.org/linux/man-pages/man2/futex.2.html

Maybe? No clue on my end and still no pi to try stuff on
Not quite what I needed, but might be workable with.
by MikeDB
Mon Oct 14, 2019 10:23 am
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

@MikeDB - I haven't tried running the 64-bit compiler myself, I was just providing some background information. @Kendek's instructions look to be clear, thorough and plausible, so I just you give them a go. Cross-compilation on the pi (armv7-> armv8) is possibly another option - crosstool-ng makes ...
by MikeDB
Mon Oct 14, 2019 8:55 am
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

To explain a little, chroot lets you run a process (an application, script or shell) with any directory as its root. This acts as simple sandbox, but also allows applications that require different system files (libraries, etc.) to be run without needing to add or overwrite system files on the host...
by MikeDB
Sun Oct 13, 2019 9:57 pm
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Wilfried - Did you come up with a solution to this ? It seems odd to me to have to have an x64 machine to compile anything to run on a Pi. But there is a solution, just chrooting into an arm64 root ( for example, unpack the Ubuntu base tar.gz ). Not as comfortable as cross-compile, but easy enough....
by MikeDB
Sun Oct 13, 2019 9:02 pm
Forum: Networking and servers
Topic: Installing Apache on Pi4 ?
Replies: 5
Views: 481

Re: Installing Apache on Pi4 ?

E: Repository 'http://raspbian.raspberrypi.org/raspbian buster InRelease' changed its 'Suite' value from 'testing' to 'stable' N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details. Ah yes. This is a known issue caused by the fa...
by MikeDB
Sun Oct 13, 2019 8:32 pm
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

w_behne wrote:
Sun Sep 22, 2019 5:11 pm
Is a 64 bit gcc package not available (for compilation on the pi4 - I'm aware of cross-compile options ...) yet, or did I miss it?

Best regards,

Wilfried
Wilfried - Did you come up with a solution to this ? It seems odd to me to have to have an x64 machine to compile anything to run on a Pi.
by MikeDB
Sun Oct 13, 2019 8:09 pm
Forum: Networking and servers
Topic: Installing Apache on Pi4 ?
Replies: 5
Views: 481

Re: Installing Apache on Pi4 ?

> Did you remember to do sudo apt update first? Yes I did. And just tried again and my Pi still tries to upload 2.4.38.3 Update gives : pi@raspberrypi:~ $ sudo apt-get update Hit:1 http://archive.raspberrypi.org/debian buster InRelease Get:2 http://raspbian.raspberrypi.org/raspbian buster InRelease ...
by MikeDB
Sun Oct 13, 2019 12:22 pm
Forum: Networking and servers
Topic: Installing Apache on Pi4 ?
Replies: 5
Views: 481

Installing Apache on Pi4 ?

I've tried to install Apache web server on my Pi4 running Raspian Buster. I downloaded a fresh copy to a memory card and installed all updates, then did : sudo apt-get install apache2 -y But I get a load of errors as it seems to access files that don't exist. Any suggestions where the files really a...
by MikeDB
Sun Oct 13, 2019 12:15 am
Forum: Advanced users
Topic: Pi4 64-bit raspbian kernel for testing - Focus on Pi4
Replies: 198
Views: 24600

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Loaded this up on a new memory card and it seems to do what I want.

BUT ... why is the mouse so sluggish, even on the fastest setting ? On the normal kernal it's fine. Any suggestions what to change to fix it ?

Thanks
by MikeDB
Sat Oct 12, 2019 7:52 pm
Forum: General discussion
Topic: "Realtime" audio output using RPi?
Replies: 4
Views: 441

Re: "Realtime" audio output using RPi?

Just use a standard I2S codec for analogue in and out. You can edit the ALSA libraries to reduce the buffer sizes to 9 (but not 8) to minimize latency, or write your own as it's a simple interface to program and then you can set the buffer size to 1
by MikeDB
Sat Oct 05, 2019 10:36 am
Forum: Advanced users
Topic: Inter-core communication
Replies: 3
Views: 406

Inter-core communication

I'll explain my Digital Audio Workstation system using a Pi4 first, then the problem. I run normal Linux on first two cores which handles WiFi, USB (MIDI in and out), HDMI, etc I use isolcpu to isolate the other two cores and this works fine. The third core takes control inputs from the second core ...
by MikeDB
Wed Sep 25, 2019 6:33 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM input clock (clk_pwm) frequency for Pi4
Replies: 9
Views: 411

Re: PWM input clock (clk_pwm) frequency for Pi4

Remember with a 2N7002 you'll only get 100mA drain current with a 3V drive signal max so the buzzer may be quieter than with a direct connection to the power supply
by MikeDB
Wed Sep 25, 2019 6:25 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: connecting the raspberry pi to a chromebook using a ethernet to usb cable
Replies: 2
Views: 128

Re: connecting the raspberry pi to a chromebook using a ethernet to usb cable

Why not just use WiFi ? (provided you have a suitable local router of course)
by MikeDB
Thu Sep 19, 2019 9:55 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Elegant way to tap into the GPIO?
Replies: 3
Views: 198

Re: Elegant way to tap into the GPIO?

Order yourself a pack of 5 of these https://www.aliexpress.com/item/32868096740.html?spm=a2g0s.9042311.0.0.27424c4dlNRCXL Then always order HATs you buy without the connector. You can stack these pretty high, but you also need 2 M2.5 screws of the same height to keep the structure stable. These conn...
by MikeDB
Wed Sep 18, 2019 7:12 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM to 3.5mm jack
Replies: 7
Views: 238

Re: PWM to 3.5mm jack

PWM on GPIO 40/41 is present on the earlier Pi models. Are you sure you are using the new PWM hardware? Yes - it's a Pi4 and when driving it as one would a Pi3 I had nothing. But driving a PCM1 module at an 0x800 offset seems to do the trick. Now sorting out the clocking to get best quality as that...
by MikeDB
Wed Sep 18, 2019 7:05 pm
Forum: Compute Module
Topic: PI 4 Compute module with pci-e?
Replies: 56
Views: 16232

Re: PI 4 Compute module with pci-e?

Lots of good ideas here which hopefully will be read. My thought is that if you expose PCIe, don't some of the other pins become less relevant and things that could be relocated off the board for provision by other PCBs, thereby reducing the pin count ? Alternatively if you are going to use more pin...
by MikeDB
Wed Sep 18, 2019 5:14 pm
Forum: Compute Module
Topic: Compute Module 4
Replies: 8
Views: 1053

Re: Compute Module 4

Perhaps if enough people here say they want one, that will encourage them to make one. They already know that people want a CM4 so threads like this aren't very productive. However, if you do actually use a lot of Compute Modules then you should submit feedback on https://www.raspberrypi.org/blog/h...
by MikeDB
Wed Sep 18, 2019 5:06 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM to 3.5mm jack
Replies: 7
Views: 238

Re: PWM to 3.5mm jack

I'll take that as "a separate totally undocumented PWM chip for audio" :-) How the Pi became a world standard with such a poor level of documentation is quite amazing. They're working on it. The BCM2711 peripheral documentation is coming soon. I know. But most companies release the datasheet long b...
by MikeDB
Wed Sep 18, 2019 12:10 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM to 3.5mm jack
Replies: 7
Views: 238

Re: PWM to 3.5mm jack

For anybody coming across this later The audio uses a new second PWM module on GPIO pins 40 and 41. The programming address for PCM1 is offest from PCM 0 by 0x800. Programming the FIFO seems to work correctly, but the signal is currently rather distorted so still working on that. I've also no idea w...
by MikeDB
Wed Sep 18, 2019 10:22 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM to 3.5mm jack
Replies: 7
Views: 238

Re: PWM to 3.5mm jack

I have the impression that the PI4 has changed the way audio works. I think I read there is now a separate dedicated PWM chip for audio. I'll take that as "a separate totally undocumented PWM chip for audio" :-) How the Pi became a world standard with such a poor level of documentation is quite ama...

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