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by nick.mccloud
Thu Aug 12, 2021 10:53 pm
Forum: SDK
Topic: SPI communication to multiple pico slaves
Replies: 10
Views: 938

Re: SPI communication to multiple pico slaves

I do love a bit of a challenge. How about a Pico with an I2C multiplexer on one core and the other doing SPI back to the Pi. Bit-bang the SPI on the Pi so you have control over the CS lines. I haven't looked at the Pico SPI implementation - is it the SDK that toggles the CS line between frames or is...
by nick.mccloud
Wed Aug 11, 2021 9:39 pm
Forum: SDK
Topic: SPI communication to multiple pico slaves
Replies: 10
Views: 938

Re: SPI communication to multiple pico slaves

Sure! I need to collect data from about 80 to 100 sensors. Each sensor produces 64 bit information every 2.5 ms. As a result, I hope to obtain all the data from 80 sensors in about 2.5 to 5 ms. Again, at best that's 128,000 per second, where is this information going to go? And as I sort of politel...
by nick.mccloud
Wed Aug 11, 2021 12:35 pm
Forum: SDK
Topic: SPI communication to multiple pico slaves
Replies: 10
Views: 938

Re: SPI communication to multiple pico slaves

I want to transfer data at Mbps level, since I need to acquire sensor datas from tens of sensors. Are there any more requirements that would be good to know? If you are transferring data at that speed, where will it go when it gets to the master Pico - you can fill the RAM in a couple of seconds at...
by nick.mccloud
Tue Aug 10, 2021 10:06 pm
Forum: SDK
Topic: SPI communication to multiple pico slaves
Replies: 10
Views: 938

Re: SPI communication to multiple pico slaves

As you say, SPI needs a CS line for each device which doesn't scale well.

Depending on your transfer requirements, I2C is so much simpler and you can have lots & lots of remotes on the pair of wires.
by nick.mccloud
Sat Aug 07, 2021 9:23 pm
Forum: General
Topic: Could a Pico be used to make a Gamepad?
Replies: 3
Views: 280

Re: Could a Pico be used to make a Gamepad?

Succinct threads for the win!
by nick.mccloud
Thu Aug 05, 2021 9:53 pm
Forum: General
Topic: USB Keyboard with persistent key presses
Replies: 6
Views: 450

Re: USB Keyboard with persistent key presses

This may help, taken from: https://wiki.osdev.org/USB_Human_Interface_Devices Auto-repeat One thing that makes USB keyboards a pain is that there is no mechanism for auto-repeat and auto-repeat delays in hardware; this must be implemented entirely in software, unlike PS/2 keyboards. For an example a...
by nick.mccloud
Thu Aug 05, 2021 11:17 am
Forum: General
Topic: Need advice, to detect external power using Pico + Op Amp
Replies: 15
Views: 848

Re: Need advice, to detect external power using Pico + Op Amp

You would probably be better to use an opto-isolator. You might get away with running the LED from 5-24V with a large dropper resistor. It would be quite dim at 5V, but maybe sufficient to turn on the output transistor. The voltage range will make this somewhat of a lottery. Whereas two resistors p...
by nick.mccloud
Wed Aug 04, 2021 4:51 pm
Forum: General
Topic: Need advice, to detect external power using Pico + Op Amp
Replies: 15
Views: 848

Re: Need advice, to detect external power using Pico + Op Amp

If the voltage source can deliver a few mA a simple resistor divider will do the job just as well.

See https://ohmslawcalculator.com/voltage-d ... calculator - 35k & 5k should do nicely.
by nick.mccloud
Tue Aug 03, 2021 10:50 pm
Forum: General
Topic: RP2040 now available at JLC PCB
Replies: 18
Views: 1915

Re: RP2040 now available at JLC PCB

Normal chip inventory levels would be, for example, what Mouser has in stock for a given package and speed. And that most if not all package/speeds are available in unit quantity when needed. Under the 'new normal' that could mean pretty much anything anyone in Marketing wants it to - as knowing wh...
by nick.mccloud
Tue Aug 03, 2021 7:33 pm
Forum: General
Topic: RP2040 now available at JLC PCB
Replies: 18
Views: 1915

Re: RP2040 now available at JLC PCB

As I said above, the worldwide chip supply problem is affecting us as well as everyone else, and is getting worse. Indeed, CEO of ST Micro quoted yesterday as saying expect shortages until sometime first half of 2023 - "By "normal situation," Chery said he meant regular chip inventor...
by nick.mccloud
Sun Aug 01, 2021 9:13 pm
Forum: SDK
Topic: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)
Replies: 69
Views: 3280

Re: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)

I don't know what would happen if RPF and RPT amicably separate, RPT becomes an entity in its own right, who gets to own the naming rights and the github URL's, but if something needs to change, everything needs to change. If this helium snowball concept manages to exist in the next major coronal m...
by nick.mccloud
Sun Aug 01, 2021 8:18 pm
Forum: SDK
Topic: is the arduino support for RPI2040 better then CMAKE ????
Replies: 51
Views: 3016

Re: is the arduino support for RPI2040 better then CMAKE ????

There is an argument that one shouldn't even need to include header files when the compiler and/or build system can figure out what header files need to be included and which libraries need to be linked. That's just imposing an unnecessary burden on the user by forcing them to include them, having ...
by nick.mccloud
Sun Aug 01, 2021 7:35 pm
Forum: General
Topic: Build project with makefile
Replies: 21
Views: 1072

Re: Build project with makefile

When I was a lad, just after punch cards didn't become a thing, we still had to wait for a considerable time (many minutes, sometimes hours) to get any Pascal compile results out of the MicroVAX we used at University. When I learned Pascal at University, we handed the punched cards in during the af...
by nick.mccloud
Wed Jul 28, 2021 12:54 pm
Forum: SDK
Topic: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)
Replies: 69
Views: 3280

Re: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)

But I suspect "whinging customers" don't sway things in their favour, certainly don't for me. They way I see it; if I have provided customers with something and it doesn't do what I said it would do, stops doing what I said it would do, my customers have complete legitimacy in whinging ab...
by nick.mccloud
Wed Jul 28, 2021 11:41 am
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 323
Views: 16499

Re: Pi Pico - the most user un-friendly MCU?

There is typo in the title: as Pi Pico is -at least : maybe pios should be seen as fractional MCUs- dual core, odds it gts hated are at least twice odds an orinary ARM get hated. Additionally, the title is incorrect in so much that the Pico isn't an MCU. I wonder if a Nano RP2040 Connect is a frien...
by nick.mccloud
Wed Jul 28, 2021 11:36 am
Forum: SDK
Topic: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)
Replies: 69
Views: 3280

Re: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)

Here's the $64K question; should users bear the inconvenience of making things easier for the vendor or should the vendor bear the inconvenience of making things easier for the users ? I'm sure the vendor will happily make things easier if you fund it. Making another one to avoid reputational damag...
by nick.mccloud
Wed Jul 28, 2021 9:11 am
Forum: SDK
Topic: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)
Replies: 69
Views: 3280

Re: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)

$ sudo apt update $ sudo apt full-upgrade could be used to keep everything including the SDK up to date. It's obviously not a big deal. We did consider this, but there are downsides which meant we were not happy with it as the main install process. Just in case anyone is wondering, there is nothing...
by nick.mccloud
Tue Jul 27, 2021 11:01 pm
Forum: SDK
Topic: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)
Replies: 69
Views: 3280

Re: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)

ejolson wrote:
Tue Jul 27, 2021 10:25 pm
If that were the case, then

$ sudo apt update
$ sudo apt full-upgrade

could be used to keep everything including the SDK up to date.
:roll:
by nick.mccloud
Tue Jul 27, 2021 9:29 pm
Forum: SDK
Topic: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)
Replies: 69
Views: 3280

Re: Setting PICO_SDK_PATH in your CMakeLists.txt (hint: dont)

It would be nice if there were a Raspberry Pi OS meta package such that apt install pico-dev would install the cross compiler, the SDK and keep them up to date. If fact, the reason I placed pico-sdk in /usr/local for now is in hope of such a package. What's wrong with: wget https://raw.githubuserco...
by nick.mccloud
Tue Jul 27, 2021 9:23 pm
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 323
Views: 16499

Re: Pi Pico - the most user un-friendly MCU?

Some of the posts here suggest to me that RPT's managers and engineers were not even aware of these opportunities. Not sure if there are any managers at RPT in the pejorative sense you are implying. Somehow Eben has manage to find the last seam of "doers" in the country who's propellors s...
by nick.mccloud
Tue Jul 27, 2021 9:02 pm
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 323
Views: 16499

Re: Pi Pico - the most user un-friendly MCU?

What some folks seem to think, though, is that their complaints (regardless of how strongly they feel about them) require any kind of action aside from "I read what you said but we are currently doing it this way". This. This is a key concept. The Henry "you can have it in any colour...
by nick.mccloud
Mon Jul 26, 2021 11:07 am
Forum: General
Topic: Current consumption on sleep modes
Replies: 30
Views: 2300

Re: Current consumption on sleep modes

If you power SRAM off it does lose its contents, its not flash. From the RP2040 data sheet: 2.11.4. Memory Power Down The main system memories (SRAM0...5, mapped to bus addresses 0x20000000 to 0x20041fff), as well as the USB DPRAM, can be powered down via the MEMPOWERDOWN register in the Syscfg reg...
by nick.mccloud
Mon Jul 26, 2021 10:54 am
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 323
Views: 16499

Re: Pi Pico - the most user un-friendly MCU?

aallan wrote:
Mon Jul 26, 2021 9:52 am
Everything "just" works on macOS.
Agreed
You install Homebrew, which every macOS-based developer has installed anyway, and then follow the Linux instructions.
Erm, maybe not all :D

https://www.imdb.com/title/tt0079470/quotes/qt0471953
by nick.mccloud
Sun Jul 25, 2021 9:59 pm
Forum: General
Topic: Current consumption on sleep modes
Replies: 30
Views: 2300

Re: Current consumption on sleep modes

or the current situation is considered good enough and the battery powered, mostly sleeping sensors are simply not the target projects for those chips? I do a fair amount of IoT at present and for most of the battery powered stuff a single core running at 4 or even just 2MHz is more than sufficient...
by nick.mccloud
Fri Jul 23, 2021 11:21 pm
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 323
Views: 16499

Re: Pi Pico - the most user un-friendly MCU?

But, from a user's perspective - especially those who may be struggling and frustrated, improving the situation is merely a matter of money, resources and the will to do it, so it's not unreasonable they aren't always sympathetic to 'that's how it is' explanations. The expectations lack any reasona...

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