leaflabsandy
Member
Being a hardcore Arduino user and the Maple is an Arduino compatible in form and
commands/functions.
D represents digital - so when an Arduino user programs a sketch he knows that pin #
"0" (not microcontroller pin #) is the same as "D0" in his program code.
The silkscreen on the Arduino is 0-14 for digital and 0-6 for analog.
Note: The analog is a subset of the digital I/O.
Maple r5 design files have been pushed:
gbulmer
Moderator
As a medium time Arduino user, and someone who has built hardware based on Arduino, I have NEVER used D0 in a sketch/program.
It doesn't compile in the Arduino IDE. The error is, e.g.
error: 'D0' was not declared in this scope
I can't remember ever seeing any sketches that used that notation, though I haven't read all the examples. To use it, it would have to be #defined as declared somewhere, and I think I'd have noticed that.
mbed does it that way. Maybe you're thinking of that?
Which pin '0' refers to is usually pretty clear from context, e.g. it's used in a 'digital' or 'analog' I/O library call.
The silkscreen on my Arduino Diecimilia numbers the digital pins from 0 to 13.
There is no digital 14 (I was surprised when Maple added it, as that is incompatible with Arduino).
The other two pins on the two 8 pin digital I/O headers is GND and AREF.
In the Arduino library and headers, analogue pin 0 is aliased as digital pin 14, upto analogue pin 5, which is aliased as digital pin 19.
HTH
leaflabsandy
Member
Quote: "As a medium time Arduino user, and someone who has built hardware based on Arduino, I have NEVER used D0 in a sketch/program."
Reply: I don't either - what I tried to convey that the Pin # is a digital bit and
if ref. to D0-D13.(sorry about using D14 - the Maple has this) unless used as an analog.
poslathian
LeafLabs
the issue with d14 is that the rbt6 doesnt have an aref pin. While the analog supply, vdda, is separate, its nominally 3.3v, and that feature just doesnt exist on that chip. We figured we might as well not waste a perfectly good gpio, I suppose we could have left the trace unconnected. Incidentally, some of the larger stm32's do have an aref, including, I believer, the Maple Native.
gbulmer
Moderator
Poslathian, just to clarify for folks.
Members of the STM32F101, STM32F103, STM32F105 and STM32F107 family, which come in LQFP100 and LQFP144 packages have analogue reference Vref+ and Vref-. (I haven't looked at the STM32W or STM32L to have noticed).
Also, STM32F103's in a TFBGA64 (same number of pins as the Maple's LQFP64) has an analogue Vref+, but no Vref-. The TFBGA64 version loses PC3. I have no idea why they did that; it's weird to me.
One key thing about adding the d14 to the Maple header is the Arduino analog pin 0 is aleady aliased to digital pin number 14 in the Arduino libraries. This might make sharing some libraries slightly more complex.
It's done now - ship it :-)
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