david.prentice wrote: ↑
Tue Oct 10, 2017 8:56 am
I had assumed you were in US or Europe. Nucleo boards take 24 hours to arrive from our local distributors.
Compared with Due clones or STM32 BluePill taking 10-40 days from China.
ha, hilarious: it's definitely the other way round for me... with the strong possibility that stuff will... magically... disappear at customs unless it's from a courier like DHL or Fedex. the import tax on electronics in to china is THIRTY PERCENT, and that's only for "permitted" stuff. Taiwan and HK are different though.
You know what the Chinese and Taiwan local markets are like.
i'm mostly familiar with china, only been here in taiwan for... eight months? TW doesn't actually have significant electronics markets (they have expertise, universities and head offices instead), it's more like... radio shack but they're gone even before radio shack could have got going here. there's *TWO* electronics components stores in the whole of taipei city (!) whereas there's an entire *district* dedicated to components in Shenzhen, and dozens of small ones in Hong Kong.
The US / European hobbyist will pay more for hardware. But they would expect the software to be painless. Arduino for STM32 is not as well supported as Arduino for SAM3X8E. We do not consider the Due-clones to be expensive. From your point of view, it should be profitable for both manufacturer and retail.
well, here's the thing: i trained as a software engineer, specialising in reverse-engineering, embedded systems programming, linux kernel development and so on. the programming side i don't exactly take for granted but i can do it. then i moved into libre hardware, with a view to creating eco-conscious hardware that actually properly honours libre software licenses, but is marketed as "lower cost of ownership because you can keep it around for longer" - long story.
anyway part of that meant that i had to actually find low-cost parts in the first place: it's no good sourcing parts from digikey, you have to go to shenzhen. that in turn meant that i am now "used to" pricing here in china. therefore, in turn, i *automatically* rebel at western pricing levels.
Regarding the pcb layout. If there are 54 GPIO header pins, you only need to route the accessible pins. It would be wise to have pin-compatibility with Mega or Due. The actual choices will always be annoying to someone.
i believe i've managed to cover both... but the PUBLISHED functionality NOT repeat NOT the "unpublished but listed in the datasheet of either or both of the 2560 or SAM3XE processors".
to explain that: if someone has been using a particular pin's "alternative function", completely ignoring the arduino pin-outs and listed *STANDARD* functions, and is expecting this design to magically work for them, they can go take a long running jump off a very short pier.
however if instead they've been looking at the board and going, "huh, right here on the actual PCB it says this is I2C therefore i'm going to use it for... I2C" then they'll do absolutely fine.
i've managed to get all 16 ADCs out onto the ADC pins.. it *just so happens* that the L471 has two DACs which happen to be on two of the ADC lines as alternative functions, and it *just so happens* that two more of the ADCs *happen* to have alternative functions "CANTX" and "CANRX".
my feeling is: someone at ST has been reading the SAM3XE datasheet...
anyway with the caveat that it's *ONLY* the published functions, i've managed to get compatibility with *both* the Arduino r3 *and* the Due. thanks to someone on here who spotted that i missed the r3 compatibility on account of starting from the Arduino Reference Design and arduino.cc *didn't keep it up-to-date* grrrr...
It really comes down to the potential Sales and commercial profitability. The Chinese market might be far more important than Western sales.
I would guess that Uno clones sell by the 100000. Mega clones by the 10000. Due clones by the 1000.
You only have to look at the membership numbers of this Forum. STM32 popularity is less than the "official Arduino" boards.
There are probably more Teensy3.x sales. Mostly down to good support from Paul Stoffregen. (this is more important than hardware cost)
yehyeh. i'm a bit lucky - part of why i'm even considering this at all - is grumpyoldpizza's arduino port which covers the STML4 series. but, also, i have a 3D printing project i'm doing (and will be crowd-funding), and want to be able to offer people a lower-cost option. so... partly i will be doing this _anyway_.