4 ms·

Raspberry Pi Pico 2 lands with RISC-V cores

31 points by teleforce 2y ago

gnabgib 2y ago
Discussion (250 points, 13 hours ago, 115 comments) https://news.ycombinator.com/item?id=41192341 https://news.ycombinator.com/item?id=41192341
giancarlostoro 2y ago
I think the mods reposted this thread. This is really neat, I wonder if they'll offer their normal Pis in a RISC-V flavor. I will likely pick up one of these as soon as I can.
- deleted 2y ago
  [deleted]
jmole 2y ago
It's incredibly refreshing to see them pricing these at volume costs for non-volume buyers. The insane component prices that we pay in the US for lower volume electronics manufacturing are killing innovation and driving manufacturing to countries with actual price competition. Looking on Digikey/Mouser, you'll find that other MCUs with a similar spec are selling for at least $4-5 at qty 3000+. The RP2350 price is a lot closer to what a large volume buyer would pay for MCUs like this, and still appears to have a healthy margin on top of the cost of dies, packaging, test, etc.
- Onavo 2y ago
  Nothing refreshing about this. Their mid range Raspberry Pi Zero used to be $5, now they are giving you an underpowered microcontroller for the same price. You can get Pico 2 sized individual boards for less than $2 in Asia.
  - jmole 2y ago
    The MCU is $0.80 - $1.10. $1.10 for a dual core Cortex-M33 with 2MB flash and 512KB is a bargain in 2024 compared to other MCUs available at this time, at least in terms of prices that you'll be able to get as a regular consumer in the US. The only other chip that even comes close is the ESP32.
- dragontamer 2y ago
  I disagree. Small uC is almost entirely about peripherals and RP2040 and RP2350 barely have any peripherals worth talking about. It's always a weird strategy to me. Rasp. Pi foundation makes a bare bones no-frills chip (most models missing even Flash, fortunately RP2354 has Flash finally) in a field where processing power is not the focus. MPUs like SAMA5D27 are sub $10 and Linux capable and are still a bad Processing Power per $$$ point because Rasp Pi 5 exists which is bad because AMD Epic exists. If we go down the processing power chain, we simply end up in Server Land. The traditional use of uCs is to simplify circuit design by having one chip do 90% of any given project. Running BLDC motors? STM32 has BLDC motor uC that handles the 250V or 600V needed. (EDIT: STSPIN32F0602) You don't need much more than a Cortex-M0+ to drive BLDC either, so all the extra processing power of RP2350 is wasted. --------- RP2350 is very MPU-ish to me. It requires additional components and reviewers who love it praise features like PSRAM compatibility and talk about how Flash is cheap anyway. But that ignores that your typical uC doesn't need any external anything aside from maybe Xtals for communication.
  - dragontamer 2y ago
    Adding to my earlier post.... I think RP2xxx is best for screens and GUIs. So a game console and similar. PIO looks like it's good for a lot of digital interfaces as well. I know DVI and VGA have been proven on PIO for example and there's probably all kinds of 80s and 90s chips that need emulators or replacements that RP2xxx would be good for. So there is definitely a niche for RP2xxx chips. But it's not in power control, motor control or the like. And since it's not quite strong enough for Linux, it's a hassle to run Web Communications (wget/curl) off of it either. ------ But traditionally, game consoles were an MPU market not a microcontroller market. And if I were making a modern hobby game console, Linux capabilities would be on the top of my list to make everything more convenient. And it's really not that expensive these days to reach into proper Linux / DDR2 / NAND Flash.
  - Yoofie 2y ago
    > RP2354 has Flash finally The flash is QSPI, so its not really on die flash with a real flash controller. There is some QSPI cache but it’s really a band-aid solution to not having the real thing. People around the net don't seem to understand the difference and it can be very misleading.
deleted 2y ago
[deleted]
klysm 2y ago
I'm mostly interested how the software stack for this compares to something like STM32.
- genmud 2y ago
  Its actually really nice and well supported. I personally prefer the sdk style that PICO does it over the cubemx stuff. https://github.com/raspberrypi/pico-sdk https://github.com/raspberrypi/pico-sdk
pathless 2y ago
Remember AMD's Skybridge project? They wanted to put ARM and x86 together on one chip, but they cancelled it. I don't know why, because it seemed like a cool way to bridge the gap. Maybe they were worried it'd become a reverse trojan horse like the Apple Macintosh clones that came about shortly before Steve returned in the 90s. Seeing as Raspberry Pi has no dog in the game, and simply wants to offer the best product possible, I wouldn't be surprised if this is their intentional way of giving people RISC-V with the intent to allow them time to port their code to it so they can eventually pull the ARM stack. I say this because Jeff Geerling has a video about the Pico 2 where he explicitly says you can only use RISC-V or ARM cores. Not both sets at the same time. I think it's probably because a full migration to RISC-V would allow them to innovate a bit more and cut prices, although I don't know what the restrictions really are with ARM's IP control and pricing. At $5, every penny counts though.
- janice1999 2y ago
  AMD also had a project to make ARM CPUs that would work with its AM4 x86 socket for Amazon (Project Seattle, replace by Amazon's in-house Graviton). I see the Pico2 in a similar light. If customers want ARM or RISC-V Raspberry Pi has them covered. if the market moves away from ARM, they'll be well positioned.
- soneil 2y ago
  You can use both at the same time, but you can only use two cores. eg 2xARM, 2xRV, or one of each.

31 points by teleforce 2y ago

Discussion (250 points, 13 hours ago, 115 comments) https://news.ycombinator.com/item?id=41192341 https://news.ycombinator.com/item?id=41192341

giancarlostoro 2y ago

I think the mods reposted this thread. This is really neat, I wonder if they'll offer their normal Pis in a RISC-V flavor. I will likely pick up one of these as soon as I can.

deleted 2y ago
[deleted]

jmole 2y ago

It's incredibly refreshing to see them pricing these at volume costs for non-volume buyers. The insane component prices that we pay in the US for lower volume electronics manufacturing are killing innovation and driving manufacturing to countries with actual price competition. Looking on Digikey/Mouser, you'll find that other MCUs with a similar spec are selling for at least $4-5 at qty 3000+. The RP2350 price is a lot closer to what a large volume buyer would pay for MCUs like this, and still appears to have a healthy margin on top of the cost of dies, packaging, test, etc.

Onavo 2y ago
Nothing refreshing about this. Their mid range Raspberry Pi Zero used to be $5, now they are giving you an underpowered microcontroller for the same price. You can get Pico 2 sized individual boards for less than $2 in Asia.
- jmole 2y ago
  The MCU is $0.80 - $1.10. $1.10 for a dual core Cortex-M33 with 2MB flash and 512KB is a bargain in 2024 compared to other MCUs available at this time, at least in terms of prices that you'll be able to get as a regular consumer in the US. The only other chip that even comes close is the ESP32.
dragontamer 2y ago
I disagree. Small uC is almost entirely about peripherals and RP2040 and RP2350 barely have any peripherals worth talking about. It's always a weird strategy to me. Rasp. Pi foundation makes a bare bones no-frills chip (most models missing even Flash, fortunately RP2354 has Flash finally) in a field where processing power is not the focus. MPUs like SAMA5D27 are sub $10 and Linux capable and are still a bad Processing Power per $$$ point because Rasp Pi 5 exists which is bad because AMD Epic exists. If we go down the processing power chain, we simply end up in Server Land. The traditional use of uCs is to simplify circuit design by having one chip do 90% of any given project. Running BLDC motors? STM32 has BLDC motor uC that handles the 250V or 600V needed. (EDIT: STSPIN32F0602) You don't need much more than a Cortex-M0+ to drive BLDC either, so all the extra processing power of RP2350 is wasted. --------- RP2350 is very MPU-ish to me. It requires additional components and reviewers who love it praise features like PSRAM compatibility and talk about how Flash is cheap anyway. But that ignores that your typical uC doesn't need any external anything aside from maybe Xtals for communication.
- dragontamer 2y ago
  Adding to my earlier post.... I think RP2xxx is best for screens and GUIs. So a game console and similar. PIO looks like it's good for a lot of digital interfaces as well. I know DVI and VGA have been proven on PIO for example and there's probably all kinds of 80s and 90s chips that need emulators or replacements that RP2xxx would be good for. So there is definitely a niche for RP2xxx chips. But it's not in power control, motor control or the like. And since it's not quite strong enough for Linux, it's a hassle to run Web Communications (wget/curl) off of it either. ------ But traditionally, game consoles were an MPU market not a microcontroller market. And if I were making a modern hobby game console, Linux capabilities would be on the top of my list to make everything more convenient. And it's really not that expensive these days to reach into proper Linux / DDR2 / NAND Flash.
- Yoofie 2y ago
  > RP2354 has Flash finally The flash is QSPI, so its not really on die flash with a real flash controller. There is some QSPI cache but it’s really a band-aid solution to not having the real thing. People around the net don't seem to understand the difference and it can be very misleading.

deleted 2y ago

[deleted]

klysm 2y ago

I'm mostly interested how the software stack for this compares to something like STM32.

genmud 2y ago
Its actually really nice and well supported. I personally prefer the sdk style that PICO does it over the cubemx stuff. https://github.com/raspberrypi/pico-sdk https://github.com/raspberrypi/pico-sdk

pathless 2y ago

Remember AMD's Skybridge project? They wanted to put ARM and x86 together on one chip, but they cancelled it. I don't know why, because it seemed like a cool way to bridge the gap. Maybe they were worried it'd become a reverse trojan horse like the Apple Macintosh clones that came about shortly before Steve returned in the 90s. Seeing as Raspberry Pi has no dog in the game, and simply wants to offer the best product possible, I wouldn't be surprised if this is their intentional way of giving people RISC-V with the intent to allow them time to port their code to it so they can eventually pull the ARM stack. I say this because Jeff Geerling has a video about the Pico 2 where he explicitly says you can only use RISC-V or ARM cores. Not both sets at the same time. I think it's probably because a full migration to RISC-V would allow them to innovate a bit more and cut prices, although I don't know what the restrictions really are with ARM's IP control and pricing. At $5, every penny counts though.

janice1999 2y ago
AMD also had a project to make ARM CPUs that would work with its AM4 x86 socket for Amazon (Project Seattle, replace by Amazon's in-house Graviton). I see the Pico2 in a similar light. If customers want ARM or RISC-V Raspberry Pi has them covered. if the market moves away from ARM, they'll be well positioned.
soneil 2y ago
You can use both at the same time, but you can only use two cores. eg 2xARM, 2xRV, or one of each.