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The PIO (programmable hardware) is the most exciting aspect of this device! I think this might be a key technology differentiator in the future of microcontrol

The PIO (programmable hardware) is the most exciting aspect of this device! I think this might be a key technology differentiator in the future of microcontrollers, especially as the industry settles in on similar cores (ARM Cortex M0/4). Interfacing with weird/custom hardware is often why we need to use microcontrollers in the first place, and this will make it much easier.

zozbot234 6y ago
Except that the industry is settling on RISCV, for reasons of cost and flexibility. It's quite disappointing that Raspberry Foundation chose a clunky and limited legacy platform like M0+ for this silicon, given their educational mission.
- acdha 6y ago
  > Except that the industry is settling on RISCV, for reasons of cost and flexibility. Do you have any numbers supporting that? I see a few people on HN excited about it but the shipments are a tiny rounding error on the volume of ARM devices shipping.
- rcxdude 6y ago
  Eh, RISC-V is gaining popularity in some areas but it's very far from settled. ARM is still extremely dominant and it's not likely to go away in the near future. For this class of processors specifically there are basically no competitive RISC-V versions available today, and I would not expect to see any for a few years. I have used RISC-V professionally mainly because it was easier than worrying about licensing a different soft core for an FPGA. I have the same codebase running on an ARM cortex-m3. The RISC-V code uses far more flash and RAM (near 2x for code in flash and stack space in RAM), as far as I can tell because of awkward decisions made by the ISA (there are extensions which should improve this a little but they aren't available in the core I'm using). If it were a cost sensitive high volume application then ARM would win basically on that front alone, the license fees would be more than offset by the cost in hardware.
- kingosticks 6y ago
  I'm glad they shipped this today, rather than in n years time when RISC-V might be a real option.
  - coder543 6y ago
    RISC-V is a real option today. In fact, it has been a real option for awhile now. To provide just two quick examples: - https://www.sparkfun.com/products/15594 https://www.sparkfun.com/products/15594 - https://www.cnx-software.com/2020/12/20/esp32-c3-wifi-ble-risc-v-processor-esp8266-price/ https://www.cnx-software.com/2020/12/20/esp32-c3-wifi-ble-ri... Since Raspberry Pi was going so far as to make their own silicon, they definitely could have opted to include a RISC-V design instead of an ARM design. They simply chose not to. RISC-V would have made this product an instant buy in my books, but there are numerous Cortex-M0+-based microcontrollers and microcontroller boards out there already. The Pi Pico is appealing because of all the documentation and the ecosystem that is sure to develop around it, so I'm not here to claim that this product won't be wildly succesful, but the M0+ is just not the choice I would have expected them to make. RISC-V seems like it would have aligned much better with the Raspberry Pi Foundation's mission. In fact, if they had chosen to integrate the ESP32-C3 into this product instead of their custom silicon, people would be receiving RISC-V, WiFi, and Bluetooth -- and you can imagine how beneficial that would be. The ESP32-C3 is supposed to cost around $1, so it's not like it would have been outrageously expensive or something.
    - kingosticks 6y ago
      I do recognise what you say about there being a choice. But this project was surely years in the making and the tech had to be available back then. This isn't a huge company. This is a charity's first attempt at creating a low-cost microcontroller with first class documentation and support. And considering Upton's ARM background I think the ARM choice is the obvious one. Your point about the ecosystem and the documentation is important here, this is extremely valuable considering their mission and simply would not have existed at the same quality level if using some brand-new ESP chip - is it even available to buy anywhere yet (I can't find a seller)? And if you haven't had a look at the RP2040 datasheet[0] yet, please do - it is really something with multiple real-life examples and hints that goes a long way beyond what you usually get. If they had built something around the C3 it'd be a long while before anything near the same level could be created and in the hands of kids. They want an established ecosystem to build on, not a cutting edge one. I do not think it's a good fit (yet). [0]: https://datasheets.raspberrypi.org/rp2040/rp2040_datasheet.pdf https://datasheets.raspberrypi.org/rp2040/rp2040_datasheet.p...
- rasz 6y ago
  RISCV is the clunky one here. As you correctly ascertained RISCV is being adopted due to cost and licensing, but its technically inferior.

zozbot234 6y ago

Except that the industry is settling on RISCV, for reasons of cost and flexibility. It's quite disappointing that Raspberry Foundation chose a clunky and limited legacy platform like M0+ for this silicon, given their educational mission.

acdha 6y ago
> Except that the industry is settling on RISCV, for reasons of cost and flexibility. Do you have any numbers supporting that? I see a few people on HN excited about it but the shipments are a tiny rounding error on the volume of ARM devices shipping.
rcxdude 6y ago
Eh, RISC-V is gaining popularity in some areas but it's very far from settled. ARM is still extremely dominant and it's not likely to go away in the near future. For this class of processors specifically there are basically no competitive RISC-V versions available today, and I would not expect to see any for a few years. I have used RISC-V professionally mainly because it was easier than worrying about licensing a different soft core for an FPGA. I have the same codebase running on an ARM cortex-m3. The RISC-V code uses far more flash and RAM (near 2x for code in flash and stack space in RAM), as far as I can tell because of awkward decisions made by the ISA (there are extensions which should improve this a little but they aren't available in the core I'm using). If it were a cost sensitive high volume application then ARM would win basically on that front alone, the license fees would be more than offset by the cost in hardware.
kingosticks 6y ago
I'm glad they shipped this today, rather than in n years time when RISC-V might be a real option.
- coder543 6y ago
  RISC-V is a real option today. In fact, it has been a real option for awhile now. To provide just two quick examples: - https://www.sparkfun.com/products/15594 https://www.sparkfun.com/products/15594 - https://www.cnx-software.com/2020/12/20/esp32-c3-wifi-ble-risc-v-processor-esp8266-price/ https://www.cnx-software.com/2020/12/20/esp32-c3-wifi-ble-ri... Since Raspberry Pi was going so far as to make their own silicon, they definitely could have opted to include a RISC-V design instead of an ARM design. They simply chose not to. RISC-V would have made this product an instant buy in my books, but there are numerous Cortex-M0+-based microcontrollers and microcontroller boards out there already. The Pi Pico is appealing because of all the documentation and the ecosystem that is sure to develop around it, so I'm not here to claim that this product won't be wildly succesful, but the M0+ is just not the choice I would have expected them to make. RISC-V seems like it would have aligned much better with the Raspberry Pi Foundation's mission. In fact, if they had chosen to integrate the ESP32-C3 into this product instead of their custom silicon, people would be receiving RISC-V, WiFi, and Bluetooth -- and you can imagine how beneficial that would be. The ESP32-C3 is supposed to cost around $1, so it's not like it would have been outrageously expensive or something.
  - kingosticks 6y ago
    I do recognise what you say about there being a choice. But this project was surely years in the making and the tech had to be available back then. This isn't a huge company. This is a charity's first attempt at creating a low-cost microcontroller with first class documentation and support. And considering Upton's ARM background I think the ARM choice is the obvious one. Your point about the ecosystem and the documentation is important here, this is extremely valuable considering their mission and simply would not have existed at the same quality level if using some brand-new ESP chip - is it even available to buy anywhere yet (I can't find a seller)? And if you haven't had a look at the RP2040 datasheet[0] yet, please do - it is really something with multiple real-life examples and hints that goes a long way beyond what you usually get. If they had built something around the C3 it'd be a long while before anything near the same level could be created and in the hands of kids. They want an established ecosystem to build on, not a cutting edge one. I do not think it's a good fit (yet). [0]: https://datasheets.raspberrypi.org/rp2040/rp2040_datasheet.pdf https://datasheets.raspberrypi.org/rp2040/rp2040_datasheet.p...
rasz 6y ago
RISCV is the clunky one here. As you correctly ascertained RISCV is being adopted due to cost and licensing, but its technically inferior.