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by MikeDB
Wed Dec 01, 2021 12:07 am
Forum: General
Topic: Pico and SPDIF audio
Replies: 11
Views: 684

Re: Pico and SPDIF audio

shreekumar3d wrote:
Tue Nov 30, 2021 3:49 am
The resulting buffer is fed back to another PIO program that converts the bit lengths to actual audio samples.
Okay I've been thinking about this all day and still haven't worked out how you get a PIO to do that. Any hints ?
by MikeDB
Tue Nov 30, 2021 10:57 pm
Forum: Off topic discussion
Topic: More RPT floatation rumours
Replies: 38
Views: 1560

Re: More RPT floatation rumours

For example, the prize of a limited edition raspberry-colored 4GB Raspberry Pi 4B computer might motivate young people to learn more computer science. As a practical consideration I'd suggest a limit of one prize per person per category to make sure everyone gets a chance. In addition to being fun,...
by MikeDB
Tue Nov 30, 2021 10:55 pm
Forum: Compute Module
Topic: DF40C-100DS-0.4V availabilty/replacement
Replies: 3
Views: 158

Re: DF40C-100DS-0.4V availabilty/replacement

I would be fairly confident Hirose make the male and female connectors in equal numbers, so for every CM4 there should be 2 mating connectors out there somewhere.

But agree finding them is hard. JLCPCB who make/load my PCBS had lots until recently but have now run out.
by MikeDB
Tue Nov 30, 2021 7:26 pm
Forum: Off topic discussion
Topic: More RPT floatation rumours
Replies: 38
Views: 1560

Re: More RPT floatation rumours

As for MikeDB's point "What STM do is recognise those providing the most support and send them free samples of relevant new products and maybe RPT could consider that if they do IPO.", I suspect some element of that is going on now but more with the authorised resellers and bigger product...
by MikeDB
Tue Nov 30, 2021 5:05 pm
Forum: General discussion
Topic: Raspberry PI power supply
Replies: 20
Views: 470

Re: Raspberry PI power supply

Hike wrote:
Mon Nov 29, 2021 5:07 pm
I have found a 2.1A power bank. Do you think that 2.1amps would work?
It's always possible to underclock most Pis to reduce current requirements if you have a limited supply available.
by MikeDB
Tue Nov 30, 2021 5:02 pm
Forum: Off topic discussion
Topic: More RPT floatation rumours
Replies: 38
Views: 1560

Re: More RPT floatation rumours

If there is an IPO it's going to be interesting to see how the community changes if volunteers see it as a move from "supporting a charity" to "providing free support for a stock exchange listed company". Users still supply a huge amount of support on for example the STMicroelec...
by MikeDB
Tue Nov 30, 2021 4:36 pm
Forum: General discussion
Topic: Powering Pi4 from Dual USB/Mains switched power socket (UK)
Replies: 4
Views: 131

Re: Powering Pi4 from Dual USB/Mains switched power socket (UK)

I've been looking at dual mains switched sockets that come with dual USB chargers (3.1A total between the 2 USB's). On the site I was looking at someone asked directly if the Pi4 would be OK on one socket while nothing in the other. The answer was a yes. Has anyone tried this? I can't believe that ...
by MikeDB
Tue Nov 30, 2021 9:37 am
Forum: General
Topic: Pico and SPDIF audio
Replies: 11
Views: 684

Re: Pico and SPDIF audio

I have had success decoding SPDIF too. Here's what I am doing: one PIO program converts the SPDIF signal into run lengths. The CPU then converts these into actual bit lengths - 1.5, 1 and half. The resulting buffer is fed back to another PIO program that converts the bit lengths to actual audio sam...
by MikeDB
Mon Nov 29, 2021 7:39 pm
Forum: Off topic discussion
Topic: More RPT floatation rumours
Replies: 38
Views: 1560

Re: More RPT floatation rumours

And possibly; "In 2020, the company invested £4.9 million in the purchase of intellectual property, principally in respect of the design and development of new chips for future products". Some of that will have been for the ARM M0+ core and all the peripherals used in the RP2040. Hard to ...
by MikeDB
Mon Nov 29, 2021 7:35 pm
Forum: Off topic discussion
Topic: More RPT floatation rumours
Replies: 38
Views: 1560

Re: More RPT floatation rumours

Unless RPF are planing on a completely different direction it doesn't make sense to me. RPT has far from peaked, why throw away a good income stream whose flotation value is pretty much guaranteed to carry on increasing? Your upfront costs go up as you grow as fast as RPT has been. Think of how man...
by MikeDB
Mon Nov 29, 2021 6:03 pm
Forum: Off topic discussion
Topic: More RPT floatation rumours
Replies: 38
Views: 1560

Re: More RPT floatation rumours

One possibility is they've been told by Broadcom there won't be a successor to the BCM2711 so RPT would have to design the SoC themselves for the Pi6. That might explain them expanding their ASIC section as well.
by MikeDB
Mon Nov 29, 2021 11:39 am
Forum: General
Topic: 'Security bit' for the RP2040 ?
Replies: 7
Views: 295

Re: 'Security bit' for the RP2040 ?

... add a 75cent STM32G030 They'd normally be $0.75, but Digikey is down to 5 out of the ~100 STM32G030 variants in stock, and the cheapest is over $2 now. More worrying is that they've only got about 4500 total of all these variants in stock Pretty good supplies at LCSC/JLCPCB. 4000 in stock of th...
by MikeDB
Sun Nov 28, 2021 10:52 pm
Forum: General
Topic: 'Security bit' for the RP2040 ?
Replies: 7
Views: 295

Re: 'Security bit' for the RP2040 ?

If it's your own PCB, then the best bet for the RP2040, or the ESP32 or other processors dependent on an external flash, is to add a 75cent STM32G030 alongside via SPI or I2S and move some critical functions of your design to it.
by MikeDB
Sun Nov 28, 2021 11:11 am
Forum: General discussion
Topic: Raspberry voltage requirement
Replies: 17
Views: 579

Re: Raspberry voltage requirement

Hi, I am building a linear power supply for pi zero 2w, intended to be used as a music streamer. To add to the very sensible comments already made, if you're using the PWM output of the Pi then any old $3 switchmode PSU will probably be fine and you'll notice no difference. If you were to build a D...
by MikeDB
Sun Nov 28, 2021 11:00 am
Forum: General discussion
Topic: Help/Advice Wanted - Raspberry Pi 12V Marine Use Case
Replies: 19
Views: 499

Re: Help/Advice Wanted - Raspberry Pi 12V Marine Use Case

Does it have to be Pi based ? You might find one of the XMOS based solutions meets your list of requirements well.
by MikeDB
Sun Nov 28, 2021 10:55 am
Forum: General
Topic: Does CMAKE prevent by-function optimisations ?
Replies: 19
Views: 588

Re: Does CMAKE prevent by-function optimisations ?

Note of this should be the case. If you do a clean cmake generation it will tell you what compiler you are using (the arm-none-eabi-gcc from your environment unless you specify otherwise). Do you have a compiler code snipped and broken and correct assembler output I can try? It is the latest compil...
by MikeDB
Sun Nov 28, 2021 1:31 am
Forum: General discussion
Topic: Pi tablet using Android tablet (no, not the same old question)
Replies: 44
Views: 3216

Re: Pi tablet using Android tablet (no, not the same old question)

Why isn't there a $10 adapter on eBay to convert these touchscreens to DSI so we can plug them into the Pi just like the official screen (or even HDMI)? Do you have an old tablet you can open up and photograph ? I don't want to rip my Samsung to pieces :-) From there perhaps we can identify the bit...
by MikeDB
Sat Nov 27, 2021 8:33 pm
Forum: General discussion
Topic: Pi tablet using Android tablet (no, not the same old question)
Replies: 44
Views: 3216

Re: Pi tablet using Android tablet (no, not the same old question)

do you have a link to these websites? Looking for an affordable DSI display, so a schematic might give me some good hint what to hubt for. Google for 'tablet hardware schematic' and you'll see quite a few. Safest place is probably the fccid.io website. thanks for the hint. I thought DSI was a sort ...
by MikeDB
Sat Nov 27, 2021 2:55 pm
Forum: General discussion
Topic: Pi tablet using Android tablet (no, not the same old question)
Replies: 44
Views: 3216

Re: Pi tablet using Android tablet (no, not the same old question)

do you have a link to these websites? Looking for an affordable DSI display, so a schematic might give me some good hint what to hubt for. Google for 'tablet hardware schematic' and you'll see quite a few. Safest place is probably the fccid.io website. I thought DSI was a sort of high speed serial ...
by MikeDB
Sat Nov 27, 2021 2:46 pm
Forum: General
Topic: Does CMAKE prevent by-function optimisations ?
Replies: 19
Views: 588

Re: Does CMAKE prevent by-function optimisations ?

I mean by inserting pragmas just above a single function such as #pragma GCC optimize ("-Ofast"). For some reason this is being ignored, unless cmake is already using -Ofast by default which I suspect is not the case. #pragma GCC optimize works fine for me (although i usually pair it with...
by MikeDB
Sat Nov 27, 2021 12:00 pm
Forum: General
Topic: What is the fastest way transmit byte from pico to rpi through UART?
Replies: 4
Views: 247

Re: What is the fastest way transmit byte from pico to rpi through UART?

Use I2C as that seems to work fairly well. But SPI from pi to pico doesn't work well so don't try that.
by MikeDB
Sat Nov 27, 2021 11:57 am
Forum: General discussion
Topic: Pi tablet using Android tablet (no, not the same old question)
Replies: 44
Views: 3216

Re: Pi tablet using Android tablet (no, not the same old question)

People, c'mon... we've got to figure out a way to make this old stuff that still works keep working. There are several 'hardware recycling' websites will full schematics for old tablets, including the popular Samsung ones. Most of these have a simple 16 bit data port using a common LCD controller (...
by MikeDB
Sat Nov 27, 2021 11:15 am
Forum: General
Topic: Does CMAKE prevent by-function optimisations ?
Replies: 19
Views: 588

Re: Does CMAKE prevent by-function optimisations ?

I'm now pretty sure that by-function optimisations are disabled in some manner. what do you actually mean by this? Seen some code that was obviously inefficient so copy-pasted it to the CubeIDE system for the STM32G0 which also uses the M0+ core and the code alters with optimisation level. does it ...
by MikeDB
Sat Nov 27, 2021 2:14 am
Forum: General
Topic: Does CMAKE prevent by-function optimisations ?
Replies: 19
Views: 588

Re: Does CMAKE prevent by-function optimisations ?

I'm now pretty sure that by-function optimisations are disabled in some manner. Seen some code that was obviously inefficient so copy-pasted it to the CubeIDE system for the STM32G0 which also uses the M0+ core and the code alters with optimisation level. Also found that computed gotos still point t...

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