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by jamesh
Wed Jun 23, 2021 6:55 pm
Forum: General discussion
Topic: Half price Raspberry Pi Pico
Replies: 9
Views: 271

Re: Half price Raspberry Pi Pico

One trip to Aldi I came away with a jet wash and a ladder platform. Only wanted cheese.
by jamesh
Wed Jun 23, 2021 3:09 pm
Forum: Beginners
Topic: Some general questions re raspberry pi 4
Replies: 2
Views: 79

Re: Some general questions re raspberry pi 4

1.
2. Leave the SD card in - its effectively the "hard drive" for the Pi. Which may answer #1

Don't know about the others.
by jamesh
Wed Jun 23, 2021 2:40 pm
Forum: General discussion
Topic: Half price Raspberry Pi Pico
Replies: 9
Views: 271

Re: Half price Raspberry Pi Pico

No new product, but given chipagedon, a surprising deal!
by jamesh
Wed Jun 23, 2021 1:17 pm
Forum: SDK
Topic: Interleaved fast PWM for DC DC Buck
Replies: 5
Views: 150

Re: Interleaved fast PWM for DC DC Buck

This is not my stuff, just notes I made from someone else's comments. And I will flag this thread up to that person as he is the one who will need to answer your questions as I have no idea.
by jamesh
Wed Jun 23, 2021 9:45 am
Forum: SDK
Topic: Interleaved fast PWM for DC DC Buck
Replies: 5
Views: 150

Re: Interleaved fast PWM for DC DC Buck

Found some more notes. Yeah the trick here is you drive the two FETS from channel A and B of the same PWM slice, with the B channel inverted, and phase-correct mode turned on. You make sure there is a small offset between A and B. The sequence of events then goes: Start counting up from 0 -- A is on...
by jamesh
Tue Jun 22, 2021 9:07 pm
Forum: Troubleshooting
Topic: Any Updates on the Pi Zero Wifi in South Korea Issue?
Replies: 19
Views: 470

Re: Any Updates on the Pi Zero Wifi in South Korea Issue?

Okay, FW vs SW definitions aside… let me state again. I am using a brand new download of the OS — this Pi Zero had never been powered up since I bought it a year or so ago. This past weekend I prepared a new micro SD card for it. Is there some way to query the WiFi chip firmware version to confirm ...
by jamesh
Tue Jun 22, 2021 4:02 pm
Forum: SDK
Topic: Interleaved fast PWM for DC DC Buck
Replies: 5
Views: 150

Re: Interleaved fast PWM for DC DC Buck

From some notes, so might not make sense: It should be possible to do something like this using two PIO's channels to introduce the deadband, which would be in 10's of ns range. Two slightly different values in compare unit A and compare unit B, the non-overlap times would always be symmetrical. Bec...
by jamesh
Tue Jun 22, 2021 2:25 pm
Forum: Troubleshooting
Topic: Any Updates on the Pi Zero Wifi in South Korea Issue?
Replies: 19
Views: 470

Re: Any Updates on the Pi Zero Wifi in South Korea Issue?

GlowInTheDark wrote:
Tue Jun 22, 2021 2:22 pm
To me, firmware means hardware.
That doesn't change.
It should. Firmware IS software. One definition is permanent software programmed into a read-only memory. Nowadays, its usually either in EEPROM or loaded in to RAM built in to a device, at run time.

But firmware IS software. Not hardware.
by jamesh
Tue Jun 22, 2021 2:18 pm
Forum: MicroPython
Topic: How to use tkinter with MicroPython
Replies: 23
Views: 710

Re: How to use tkinter with MicroPython

GCC's incredible success seems to me to be entirely down to being able to take code and have it run on anything without having to change that code. Programmers can write their code once and it can run on anything. That's how I think it should be. That nothing to do with GCC and everything to do wit...
by jamesh
Tue Jun 22, 2021 1:37 pm
Forum: Troubleshooting
Topic: Pi 4 Cli works but startX results in hdmi blue/no signal screen
Replies: 6
Views: 177

Re: Pi 4 Cli works but startX results in hdmi blue/no signal screen

As above, you should never use sudo startx, so you need to find out what's happening there before we try and diagnose the HDMI issue.
by jamesh
Tue Jun 22, 2021 1:35 pm
Forum: Troubleshooting
Topic: After I've updated the EEPROM latest I have no DSI display image (black)
Replies: 16
Views: 441

Re: After I've updated the EEPROM latest I have no DSI display image (black)

robobostes wrote:
Tue Jun 22, 2021 12:42 pm
apart from that it's black. I think it's a problem with this RaspberryPI - where can I get a replacement???
Any of our normal distributors can supply Raspberry Pi's.

Bottom of this page to find a local one.

https://www.raspberrypi.org/products/ra ... 4-model-b/
by jamesh
Tue Jun 22, 2021 1:32 pm
Forum: Troubleshooting
Topic: Any Updates on the Pi Zero Wifi in South Korea Issue?
Replies: 19
Views: 470

Re: Any Updates on the Pi Zero Wifi in South Korea Issue?

To me, firmware means hardware. But now I remember that in the Rpi context, the term is used differently. It means the stuff in /boot. So, point taken. Firmware != hardware. Not just in the RPi context, firmware has a pretty standard definition! And no, its doesn't mean the stuff in boot. It means ...
by jamesh
Tue Jun 22, 2021 12:28 pm
Forum: Troubleshooting
Topic: Any Updates on the Pi Zero Wifi in South Korea Issue?
Replies: 19
Views: 470

Re: Any Updates on the Pi Zero Wifi in South Korea Issue?

Yes, that is a firmware issue. Are you sure you are up to date with the distribution? There have been a few wireless firmware changes on the last year or two.
by jamesh
Tue Jun 22, 2021 11:35 am
Forum: Raspberry Pi Desktop for PC and Mac
Topic: 64 bit version?
Replies: 2
Views: 159

Re: 64 bit version?

1. Deleted some posts - note that this thread is in the Desktop forum, so correctly sited. 2. Everyone knows what he is talking about - no need for constant corrections on terminology 3. The Desktop version of Raspbery Pi OS does lag behind as its only updated when we have some spare time, and we ha...
by jamesh
Tue Jun 22, 2021 9:40 am
Forum: Advanced users
Topic: It is possible to connect two raspy pico to raspberry pi4?
Replies: 3
Views: 141

Re: It is possible to connect two raspy pico to raspberry pi4?

I want to use two raspi pico and raspi4 to control a 6 legged robot. The robot has 18 motors. So, if I move the motors, I need to two raspi picos. But I don't know it is possible to connect raspi4 to two picos. So, please teach me anyone. Yes, there are a few options. You could use serial UARTs. Yo...
by jamesh
Tue Jun 22, 2021 9:25 am
Forum: Other projects
Topic: PRi 4B+ DPI HDMI display at the same time?
Replies: 2
Views: 99

Re: PRi 4B+ DPI HDMI display at the same time?

What does

Code: Select all

tvservice --list
return?
by jamesh
Tue Jun 22, 2021 9:11 am
Forum: General discussion
Topic: Any plans to use the C0 stepping for the Pi4B?
Replies: 10
Views: 599

Re: Any plans to use the C0 stepping for the Pi4B?

The most important change is the power gating improvements, but there are some minor bug fixes as well. These won't be noticeable as we worked round silicon issues in software prior to C0. C0 has less need of bounce buffer for SD card IO (no need up to 4GB) so there might be a tiny improvement there...
by jamesh
Mon Jun 21, 2021 2:56 pm
Forum: SDK
Topic: usb config, descriptors ... where's the doc?
Replies: 12
Views: 470

Re: usb config, descriptors ... where's the doc?

triss64738 wrote:
Mon Jun 21, 2021 2:39 pm
libusb? (+ a wrapper maybe for your preferred language)
That's a linux library, not available on the Pico.
by jamesh
Mon Jun 21, 2021 2:35 pm
Forum: Raspberry Pi 400
Topic: How is the keyboard quality on the RPi 400?
Replies: 55
Views: 6349

Re: How is the keyboard quality on the RPi 400?

opentrail wrote:
Mon Jun 21, 2021 11:24 am
I'd say it is terrible. Missing keystrokes & double keystrokes. So annoying. I have zero problems using a Mac, Razor or Logitech keyboards, but the keyboard on the RP400 is unusable.
That sounds like a HW defect - you should return it for a replacement.
by jamesh
Mon Jun 21, 2021 10:14 am
Forum: General
Topic: RP2040 chips for sale
Replies: 18
Views: 1174

Re: RP2040 chips for sale

I'm looking a modem (GSM) that can communicate with "Raspberry Pi Pico". Project functionality: When a vibration sensor sends a signal to the Pi Pico, an alarm (buzzer) will be triggered and an LED will start flashing. I need a modem that will alert me when I'm not close enough to hear th...
by jamesh
Mon Jun 21, 2021 8:57 am
Forum: C/C++
Topic: atomic or volatile, that is the question ( Whether 'tis nobler in the mind to mutex them)
Replies: 74
Views: 2056

Re: atomic or volatile, that is the question ( Whether 'tis nobler in the mind to mutex them)

I have to disagree, using mutexes it's not difficult, not complex, still robust, but far less muddled up 8-) Using mutexes is not difficult, they are an easy to understand concept. Using them to write robust multithreaded code is. Race conditions and deadlocks are good terms to start searching with.
by jamesh
Mon Jun 21, 2021 8:11 am
Forum: General discussion
Topic: Is Purchasing Pi Zero in Larger #'s Possible?
Replies: 16
Views: 612

Re: Is Purchasing Pi Zero in Larger #'s Possible?

Yes, I should have said the Pi WH above, as the device that is available off the shelf in quantity. However, for large enough orders you can also buy the Pi0 and Pi0W direct from us. Note the price WILL be more than the listed educational price per unit, but not a huge amount more for the Pi0W. Cont...
by jamesh
Mon Jun 21, 2021 8:07 am
Forum: Raspberry Pi 400
Topic: Pi400 Sub Par Keyboard
Replies: 7
Views: 320

Re: Pi400 Sub Par Keyboard

We are aware of an issue with some keyboards, the test regime has already been improved, and other mitigations are in progress. So, yes, we are "on the double". Do people really believe that we just sit on reports like this and do nothing? Just because you cannot see things happening, does...
by jamesh
Mon Jun 21, 2021 7:56 am
Forum: C/C++
Topic: atomic or volatile, that is the question ( Whether 'tis nobler in the mind to mutex them)
Replies: 74
Views: 2056

Re: atomic or volatile, that is the question ( Whether 'tis nobler in the mind to mutex them)

dsyleixa123 wrote:
Mon Jun 21, 2021 7:02 am
yes, I see, that's why I wrote I'll abandon atomic for C++: too weird and too muddled up for my skills.
Robust multithreaded code is difficult. C++'s implementation is not weird, or muddled up, it's just a complex subject requiring a complex solution.
by jamesh
Mon Jun 21, 2021 7:46 am
Forum: Advanced users
Topic: Maximum stable overclocking speed of a Pi 4 or 400
Replies: 55
Views: 2083

Re: Maximum stable overclocking speed of a Pi 4 or 400

The Cm4 doesn't have the size of the Pi4, and cannot cool as effectively, so you might need extra cooling.

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