MicroPython Forum (Archive)

pythoncoder wrote: ↑

Mon Jun 01, 2020 7:19 am

tve wrote: ↑

Sun May 31, 2020 6:39 pm

...
Just to provide a different PoV than Peter, who seems to take every opportunity to bash the esp32 ...

@tve I have no desire to "bash" the ESP32. A Ford Fiesta and a Porsche 911 both have merits. I happen to own the former So I see the importance of low cost and recognise the great work you and others have done on the ESP port. But I also recognise professional quality hardware when I see it.

It is a fact that the interrupt latency of an ESP32 is much worse than a Pyboard D, especially as it doesn't support hard IRQ's. So we are talking several ms if an interrupt happens to occur while a GC is in progress. I gather that with SPIRAM, a GC can take over 100ms. A Pyboard responds to a hard IRQ in (IIRC) about 20μs. That is a huge difference.

Another issue is stability. As you know I've done a lot of work on resilient MQTT. The Pyboard D ran for six weeks without a restart, exchanging nearly 1,000,000 messages. The test would probably still be running if my wife hadn't accidentally pulled the plug to run Christmas lights The ESP32 can't get close, resetting every few days. Testing was done using the same code, in the same physical location and the same power supply.

To be fair the ESP32 has one killer feature for those of us who need fast signals: the awesome RMT interface. I'd love to see support for this fixed and extended.

For some users price trumps performance. Some applications don't care about ISR response and can handle occasional reboots, in which case a Pyboard would be overkill. I welcome diversity, but we should document and recognise these differences otherwise new users will be puzzled and disappointed.

The other reason for supporting Pyboards is that proceeds from their sale keep this whole show on the road. I think those who can afford them should consider buying them.

kevinkk525 wrote: ↑

Mon Jun 01, 2020 5:41 am

That's nice but are there some STM32 boards with Wifi too?
Also it's nice to buy a $4 STM32 but they got no additional SPI flash so they are limited to 256kB which means you need a very special and small firmware of MP to even work with those. Also they are 411 series with only 100MHz.

rcolistete wrote: ↑

Tue Jun 02, 2020 7:30 pm

kevinkk525 wrote: ↑

Mon Jun 01, 2020 5:41 am

That's nice but are there some STM32 boards with Wifi too?
Also it's nice to buy a $4 STM32 but they got no additional SPI flash so they are limited to 256kB which means you need a very special and small firmware of MP to even work with those. Also they are 411 series with only 100MHz.

One super-microcontroller with STM32 is the Portenta H7, US$92 for default version, it started selling :
https://www.newark.com/arduino/abx00042 ... duino-2518

kevinkk525 wrote: ↑

Tue Jun 02, 2020 8:59 pm

uhm thanks, I was more interested in something close to the esp32, not more expensive than the pyboard D