4 ms·

We are starting to see SBCs that bake in an RP2040 to drive some GPIO pins (without needing to tie up a physical usb port), which seems like a reasonable compro

We are starting to see SBCs that bake in an RP2040 to drive some GPIO pins (without needing to tie up a physical usb port), which seems like a reasonable compromise... I do like the RPi Zero size/perf/price combo, but for anything that needs more horsepower it's hard to argue with the bigger NUC-a-likes.

teruakohatu 2y ago
Yes there are N100 SBCs including a RP2040, so best of both worlds.
- sthlmb 2y ago
  It’s not quite as seamless though, sadly, it’s just the same as having a Pico plugged in via USB but it’s a good step, even if the X4 (assuming that’s what we’re referring to) has some other flaws!
nxobject 2y ago
Especially when you want to work with PIO as well. Well, either way Raspberry Pi gets paid.
qhwudbebd 2y ago
Do these give you decent performance DMA-able gpio and spi like you get even on a cheap rpi4? (I'm not claiming they don't/can't, just that it isn't immediately obvious to me that they would.) For example, spi is an easy hack to bit sample a digital level and stream the results into memory for later processing. You can effortless do this at 20MHz+ plus on an rpi4. When you want to stream multiple digital levels simultaneously (in sync), DMA on gpio is a nice generalisation. (Could perhaps abuse I2S inputs too, which might be present on a more generic x86 board?) I always wonder about a nice PCIe board supporting good DMAable gpio/spi/i2c/etc on standard x86 machines. I'd probably pay a fair amount of money for a quality one. But it's a product I've never seen on the market. Bodging a USB gpio interfaces with one of the relatively low spec chipsets seem like a pale, inefficient and high-latency imitation. Actually, given the RP1, maybe the rpi5 has slow/non-DMA gpio too? I haven't been able to check it out yet as these boards still don't have mainlined linux support and I'm not up for buying toys that don't. (Am I imagining it, or did they used to be a lot better at mainlining support for their boards promptly?)

teruakohatu 2y ago

Yes there are N100 SBCs including a RP2040, so best of both worlds.

sthlmb 2y ago
It’s not quite as seamless though, sadly, it’s just the same as having a Pico plugged in via USB but it’s a good step, even if the X4 (assuming that’s what we’re referring to) has some other flaws!

nxobject 2y ago

Especially when you want to work with PIO as well. Well, either way Raspberry Pi gets paid.

qhwudbebd 2y ago

Do these give you decent performance DMA-able gpio and spi like you get even on a cheap rpi4? (I'm not claiming they don't/can't, just that it isn't immediately obvious to me that they would.) For example, spi is an easy hack to bit sample a digital level and stream the results into memory for later processing. You can effortless do this at 20MHz+ plus on an rpi4. When you want to stream multiple digital levels simultaneously (in sync), DMA on gpio is a nice generalisation. (Could perhaps abuse I2S inputs too, which might be present on a more generic x86 board?) I always wonder about a nice PCIe board supporting good DMAable gpio/spi/i2c/etc on standard x86 machines. I'd probably pay a fair amount of money for a quality one. But it's a product I've never seen on the market. Bodging a USB gpio interfaces with one of the relatively low spec chipsets seem like a pale, inefficient and high-latency imitation. Actually, given the RP1, maybe the rpi5 has slow/non-DMA gpio too? I haven't been able to check it out yet as these boards still don't have mainlined linux support and I'm not up for buying toys that don't. (Am I imagining it, or did they used to be a lot better at mainlining support for their boards promptly?)