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by okenido
Mon Aug 12, 2019 2:04 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 20530

Re: Why moving to 64bit?

I think 64 bit is mostly worth it, you get double the NEON registers, that can improve performance drastically if the software is written to take advantage of it.
However an app that is constrained by memory bandwidth limits and doing zillions of pointer manipulation will probably suffer
by okenido
Wed Jul 24, 2019 6:30 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

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by okenido
Mon Jul 22, 2019 7:42 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

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by okenido
Fri Jul 19, 2019 11:44 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

Thanks that make sense, i'ill try that asap.

Learning by trial & error :P :ugeek:
by okenido
Fri Jul 19, 2019 11:36 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

Seems that I can only transfer the first 32 bits of the frame despite I set its length to 128. Or i'm missing something. Maybe the clock divider trick you explained is the only way to go
by okenido
Fri Jul 19, 2019 11:18 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

I use the raspberry in Master mode for the sake of simplicity ^^ I received my scope and it helped a lot. For some reason, chosing a Frame Sync Length (FSLEN) greater than the Frame Length (FLEN) causes LRCLK to stop working. However, I can get the 256 BCLK per LRCLK if I just increase both FLEN and...
by okenido
Thu Jul 18, 2019 6:05 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

Yeah it seems complicated. I've tried to run I2S at 192Khz to write four 48Khz frames, while slowing down Frame Sync Length by a factor of 4 (FSLEN register, I guess it controls LRCLK ? => broadcom datasheet p.131 https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2835/BCM2835-ARM-Per...
by okenido
Thu Jul 18, 2019 2:16 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

I switched to an AD1934 DAC chip since it has integrated PLL and it works on the Raspberry Pi 3B+ ! Now I want to use TDM to get more than a single stereo output (up to 4 stereo outs on AD1934), so I setup my DAC in TDM mode and write the data like this : Ch1 L | Ch1 R | Ch2 L | Ch2R (two stereo 48k...
by okenido
Sun Jul 07, 2019 6:40 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

I made the clock on the Raspberry Pi gpio #4 (seemed the easiest solution to me) but it won't wake up the DAC, this is what I used in dt-blob.dts (took from a post on this forum) : // in pin_config section pin@p4 { function = "gp_clk"; termination = "no_pulling"; }; // GPCKL0 // in videocore section...
by okenido
Sun Jul 07, 2019 9:40 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: The I2S sound thread.
Replies: 925
Views: 463362

Re: STICKY: The I2S sound thread.

I'm currently trying to use a 8 channel DAC the PCM1960 in TDM mode (one I2S interface to control multiple outputs) with my raspberry 3B+ : http://www.ti.com/lit/ds/symlink/pcm1690.pdf Unfortunately it's one of those requiring a Master Clock in addition to the three I2S wires, master clock has to be...
by okenido
Thu Jun 27, 2019 1:57 pm
Forum: General discussion
Topic: Why do I not see 2x speed up in sysbench?
Replies: 5
Views: 663

Re: Why do I not see 2x speed up in sysbench?

The new cpu IS something between 2-3 times faster, because increased frequency, bigger pipeline, better branch prediction, bigger caches... but it's hard to measure with benchmarks. For example the big cache advantage may only show up on applications using large data sets and large code base (most a...
by okenido
Thu Jun 27, 2019 1:47 pm
Forum: General discussion
Topic: Will USB-C ever replace all other ports or just some?
Replies: 31
Views: 2805

Re: Will USB-C ever replace all other ports or just some?

USB-C is quite good I hope it will replace this trash USB-B connector which is just a total facepalm. USB-A is going to stay forever and my products will support it. No reason to change something that is used everywhere, is cheap and reliable. What wrong with USB-B? A nice robust solid connector th...
by okenido
Thu Jun 27, 2019 12:46 pm
Forum: General discussion
Topic: Will USB-C ever replace all other ports or just some?
Replies: 31
Views: 2805

Re: Will USB-C ever replace all other ports or just some?

USB-C is quite good I hope it will replace this trash USB-B connector which is just a total facepalm.

USB-A is going to stay forever and my products will support it. No reason to change something that is used everywhere, is cheap and reliable.
by okenido
Thu Jun 27, 2019 9:15 am
Forum: General discussion
Topic: About locking topics
Replies: 7
Views: 355

Re: About locking topics

Then create a unique topic dedicated to speculation, so when closing the separate topic moderators can link it
by okenido
Thu Jun 27, 2019 9:14 am
Forum: General discussion
Topic: Why is the RPi4 being advertised as a desktop computer?
Replies: 114
Views: 11380

Re: Why is the RPi4 being advertised as a desktop computer?

well we're playing with words, if any computery-thing laying on a desk can be called a desktop computer then a caravan or a tent is the same as a house, why bother having different words for different things :)
by okenido
Thu Jun 27, 2019 9:05 am
Forum: General discussion
Topic: About locking topics
Replies: 7
Views: 355

About locking topics

https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=243814 This post was made and just locked instantly. I think you guys needs to have some respect for the community, at least respect the author for the time he spends writing the post. Locking topics because they don't please someone shoudn't b...
by okenido
Thu Jun 27, 2019 8:59 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97864

Re: Raspberry Pi 4 Thread - general discussion

The base RPi 4 B should have started off at 4 GB with a socket to add more. everyone has different needs, personnally I'd even like a 512MB version since my usage needs very little RAM. 4GB is plenty for a computer with this processing power, 8GB would be quite ridiculous, it's the amount of RAM mo...
by okenido
Wed Jun 26, 2019 3:28 pm
Forum: General discussion
Topic: Why is the RPi4 being advertised as a desktop computer?
Replies: 114
Views: 11380

Re: Why is the RPi4 being advertised as a desktop computer?

I woudn't advertise the RPI as a desktop computer (I didnt know it was), yes it could be used for that but it's a bit of a stretch. The general expectations for the word "Desktop Computer" is a powerful device used for working efficiently, you don't care much about its size or power consumption beca...
by okenido
Wed Jun 26, 2019 8:40 am
Forum: Bare metal, Assembly language
Topic: Raspberry Pi 4
Replies: 59
Views: 9478

Re: Raspberry Pi 4

Dunno why in 2019 GPU drivers/programming is still such a pain in the ass. Libraries are huge. APIs are overcomplicated. Drawing a simple 2D line is ridiculously hard if you want proper hardware acceleration... or rely on libraries like OpenVG but it seems quite slow from my experiments. I dream of ...
by okenido
Tue Jun 25, 2019 9:23 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97864

Re: Raspberry Pi 4 Thread - general discussion

Hi, I have a product using the raspberry 3B+ with bare metal code... I'm using quite a lot of things currently : MMU, NEON SIMD, I2C, I2S, framebuffer access (software rendering), USB mass storage, EMMC read/write access, interrupts... How hard would it be to get it running on the raspberry 4 ? I'm ...
by okenido
Mon Jun 24, 2019 7:55 pm
Forum: Bare metal, Assembly language
Topic: Raspberry Pi 4
Replies: 59
Views: 9478

Re: Raspberry Pi 4

I'm also interested into this... super excited by this new raspberry, but I have already my product developed in bare metal around the RPI 3, wondering how hard it would be to support the new SoC.
I guess the ARM core isn't that much different but I'm more worried about the peripherals.
by okenido
Mon Jun 24, 2019 3:15 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97864

Re: Raspberry Pi 4 Thread - general discussion

EMMC really isn't a very good option IMO. Less reliable than SD cards over multiple writes and you cannot replace it when it fails, like you can with an SD card. SD also allows the possibility of keeping different software configs and solutions, per SD card. Oh, and as far as controlling costs, I'm...
by okenido
Mon Jun 24, 2019 3:07 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97864

Re: Raspberry Pi 4 Thread - general discussion

WOW well done the rpi team I'm so excited !! The new cpu with its much longer pipeline has the potential to be 2 times more powerful at the same frequency, and with the much bigger cache and faster memory the announced 3X performance bump seems legit ! Do you know if the I2C bug has been corrected i...
by okenido
Mon Jun 03, 2019 1:54 pm
Forum: General discussion
Topic: Why 80 pin IDE cable fried my Pi
Replies: 11
Views: 580

Re: Why 80 pin IDE cable fried my Pi

That cable WAS DESIGNED and INTENDED FOR USE with IDE drives and NOT FOR THE RPi GPIO. It was your fault for using it, that fried your RPi, not the fault of the designer of the cable. saw this in one article: "....somebody put raw eggs in a microwave oven and it exploded upon turning on....causing ...
by okenido
Mon Jun 03, 2019 1:46 pm
Forum: General discussion
Topic: Why 80 pin IDE cable fried my Pi
Replies: 11
Views: 580

Re: Why 80 pin IDE cable fried my Pi

well, no problem with that, but creating interconnections in a cable with separate pins is misleading in my opinion, such things should be done on the board so the cables stays as standard as possible... but okay !

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