The RP2040 is a Cortex-M0, which is about the smallest core you find on modern systems but still a pipelined 32 bit RISC machine running in the dozens of MHz.
Note though, that the article is really about the PIO device on these SOCs', which isn't part of the main CPU at all. It's sort of a very limited programmable hardware engine for the specific task of doing PCB level interconnect using GPIO and lightly buffered streaming. In some sense it's like a thematic midpoint between an FPGA and a CPU.
It's... honestly it's just really weird. And IMHO has really, really, REALLY limited application. It's for people who would otherwise be tempted to bitbang an I2C or UART, but not for ones who can put hardware on the board themselves, or who have a FPGA handy, or even for people who want to do non-trivial stuff like QSPI displays[1] or whatnot.
Basically PIO smells like a wart to me. I genuinely don't know who wants it. Regular hackers aren't sophisticated enough to use it productively and the snobby nerds have better options.
[1] The linked article appears to be doing a quarter-VGA display in 3-bit/8-color, and is sort of right at the limit of the power of the engine.
> The linked article appears to be doing a quarter-VGA display in 3-bit/8-color, and is sort of right at the limit of the power of the engine.
The resolution and color depth restrictions were the product of the low data rate of USB FS (~12 Mbps), not inherent limitations of PIO.
> It's... honestly it's just really weird. And IMHO has really, really, REALLY limited application.
I'd agree with "weird". But it's useful weird; it turns out that there are a lot of situations where PIO can avoid the need for an application-specific peripheral, and can provide that function in a more flexible fashion than a fixed-function peripheral could. Dmitry's SDIO device emulator is a great example - almost every other SDIO peripheral on the market is host-only.
> it turns out that there are a lot of situations where PIO can avoid the need for an application-specific peripheral
And I can only repeat: I think that's an aspirational delusion. I'm not aware of anyone shipping a PIO solution to anyone in volume. It's "useful weird" to Hackerspace nerds like us, and that leads to some epistemological skew.
Hardware needs to be boring and reliably supported (by people you can sue!) or else no one will bet a 10k unit PCB run on it. This is anything but.
>Basically PIO smells like a wart to me. I genuinely don't know who wants it. Regular hackers aren't sophisticated enough to use it productively and the snobby nerds have better options.
I mean, I applaud your work. But let's also be honest (in the "tough love" sense): those are all toys with significant limitations that preclude anyone shipping any of them on an actual device to an actual consumer. I mean, your SOC (maybe a $2 one) surely already includes a SPI master and USB host!
Actual interconnects that solve real market problems have big boring spec books and competing implementations and silicon vendors. The application for PIO is basically limited to "I have to connect to this crazy old junk and no one makes the part I'd otherwise need".
Having dealt with the errata sheets for microcontrollers with all those fancy IO devices that solve real marketing problems etc, I'd kill to fix those problems with a software upgrade.
if you find a SoC for $1 that has 2 Ethernet ports, and a usb host on it, while also having two cores and supporting 32MB of RAM you'll surprise me. rp2350 does all of the above for $1
Have you tested out the 2x PSRAM configuration; if so, have you written anything up about it? :) I've thought about a configuration like that myself but haven't committed to any hardware yet.
How are you handling startup? The approach I had in mind was putting boot flash on the second channel with a separate CS pin from PSRAM and configuring that in OTP; any idea if that would work?
Yes, sort of. Basically a tiny loader in OTP that enables nCS1 on some pin, copies code from there to ram on nCS0, reconfigures nCS1 to point to second ram. This does break usb flashing. Use swd.
Is there no way to do that without code in OTP? The bootrom is supposed to scan for an IMAGE_DEF on both memory banks, and can use nCS1 as specified in FLASH_DEVINFO. Unless there's something I'm missing, that should be sufficient.
> I'm still angry they killed flash. There has never been a better platform for non-technical folks
Capcut and Roblox would like words. No, that's kinda just wrong. Content generation for non-technical folks has never been easier or more effective. Flash is just something nerds here remember fondly because it was a gateway drug into hackerdom. Some of us are older and might feel the same way about Hypercard or TurboPascal or whatnot.
A PWA on iOS is just a cached web page. Safari remains pretty crippled with regards to the APIs (bluetooth, usb, filesystem, etc...) that make local apps attractive in the first place. Apple is fine with letting people cache web pages, they're not fine with stuff that might displace the app store.
And for that I'm quite thankful, if all the stuff that apps could do were possible on the web it would make the web a far far scarier place than it is.
I avoid apps as much as possible due to all the nefarious tricks they play, even with all the sandboxing and review they go through. Without those constraints, I can't imagine the hell that we'd be in.
Which is fine, for the 90% of people that spend their time on the 70% of common features and interact only with the screen and headphones and internet.
But sometimes people like to do stuff like configure their QMK keyboards or load new firmware for their EdgeTX drone radios or make bootable USB sticks, all tasks that work just fine in easily deployed PWAs on every client platform in existence, except iOS.
For small developers of small-yet-oddball clients apps, PWA's are an absolutely magnificent platform. Write once, deploy once, run... everywhere-but-an-iPhone. It really sucks that Apple's devices are crippled like this.
Edit to reply to this bit:
> Without those constraints, I can't imagine the hell that we'd be in.
Again, that hell is literally every other platform on the planet. It's only Safari that is "protected". In point of fact browser permissions management on this stuff tends strongly to be stricter and less permissive than app permissions, which are much less visible.
I mean, there are practical reasons too (which are mostly just isomorphic to the stuff in the paper). But really that's why. It's part of our cultural history in ways that more esoteric math isn't.
Because people like me use quaternions but have never attained a full understanding like 3x3 rotation matricies. I will be reading the above link since its only 12 pages and someone indicated its an easier read.
> biometrics on phones is just another way so-called "tech" companies perform data collection ultimately to be used for commercial purposes
No, sorry, that's just silly. Routine biometrics have made personal devices near-unhackable and almost un-stealable. They have turned automated password attacks into a historical memory. They are a huge boon to consumers. Yuge, even.
Can they be abused? Yeah, sure. I guess everything can. But to cynically claim they have no value, or negative value, is just detached from reality.
Yes, but even so doing it because of protest is a restraint on speech, and that's expressly prohibited by the constitution.
The first amendment may be frustratingly silent on fruit trade regulations, but it's 100% not unclear about abridging the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
> Liquidity is still in abundance and no other market can capture that liquidity.
I don't know what that means? Market crashes are changes in speculative value, they don't care about counting literal amounts of currency. Selling US securities doesn't require that the resulting "liquidity" move anywhere else, just that the owner prefers to see a cash balance to a stock certificate or whatever.
Basically this point seems like a big "confused money with value" mistake.
Literally the whole economy has "over-raised its fundamentals" though. Not everyone is going to fail in exactly this way, but (again, pretty much literally) everyone is exposed to a feedback-driven crash from "everyone else" that ended up too exposed.
We all know this is a speculative run-up. We all know it'll end somehow. Crashes always start with something like this. Is this the tipping point? Damned if I know. But it'll come.
This is reasoning from a mistake. Market valuation is about VALUE, which is an abstract idea assigned by the market, which is not the same thing as MONEY, which can be "printed"[1]. Market values go up and down on their own, irrespective of the amount of money in circulation. They reflect consensus (often irrational) for what the securities "should be trading at", and that's all. If the currency inflates or deflates, the markets do too.
[1] Though recognize that by engaging in that frame you're painting yourself as an unserious amateur being influenced by partisan media. Real governments do not "print money" in any real sense, and attempts to conflate things like bond debt with it run afoul, yet again, of the money/value mistake.
Emergency braking in non-camera/non-LIDAR cars requires a significant radar signal which you're only going to get from another vehicle (and even then it's noisy and tends to produce frustrating false positives, leading to later-than-you-want stops). It very likely won't detect a child or a dog, I'm not aware of a single instance of an EBS claiming to have done so in practice (and kids and dogs get hit every day!).
So... the thing is it's really not. They're behind on schedule, having just launched in public. But FSD has been showing capabilities in regular use (highway navigation, unprotected left turns in traffic, non-geofenced operation areas based solely on road markings) that Waymo hasn't even tried to deploy yet.
It's much more of a competition than I suspect a lot of people realize.
Note though, that the article is really about the PIO device on these SOCs', which isn't part of the main CPU at all. It's sort of a very limited programmable hardware engine for the specific task of doing PCB level interconnect using GPIO and lightly buffered streaming. In some sense it's like a thematic midpoint between an FPGA and a CPU.
It's... honestly it's just really weird. And IMHO has really, really, REALLY limited application. It's for people who would otherwise be tempted to bitbang an I2C or UART, but not for ones who can put hardware on the board themselves, or who have a FPGA handy, or even for people who want to do non-trivial stuff like QSPI displays[1] or whatnot.
Basically PIO smells like a wart to me. I genuinely don't know who wants it. Regular hackers aren't sophisticated enough to use it productively and the snobby nerds have better options.
[1] The linked article appears to be doing a quarter-VGA display in 3-bit/8-color, and is sort of right at the limit of the power of the engine.
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