I need to add some drawbacks to the eval boards (I think,
regardless of manufacturer, which also includes Arduino).
If most of what you do is I2C, SPI, parallel and the like, the
signals can be slow enough that interconnections and lead lengths
do not really matter.? There are three zones, processor to off
board connector, connector(s), and whatever's on your board.? Of
the three, only on your board is there any choice.
For the signals that are slow or can be made so, you can tweak
parameters to generally get it to work.
If, however, you are dealing with memory mapped chips (expansion
memory on ST micro and memory mapped graphics chips), then the
timing and lead length can be critical, and you may not have much
control over some of the signals.? This can cause malfunctions.
At this point, you may be forced into designing your own boards,
and I'd recommend 4 layer boards depending on the application.? At
100mm square, you could be paying about 7 or 8? USD for five of
them (depending on how you shop).
Considering the current design topic, none of this is too likely
to happen.? However, once your designs become more complicated,
this might become a factor to be considered.
(Been there, did that, have the boards that don't work).
Harvey
On 9/13/2022 1:31 PM, saipan59 (Pete)
wrote:
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On Tue, Sep 13, 2022 at 08:36 AM, Harvey White wrote:
I've done some display work, and I generally find that
the Arduino (at least the MEGA series) is too slow and has too
little memory to be useful for involved graphics.? However,
there's a U8xxxx library out there that seems to be a standard
for arduino projects.? I've transitioned to the STM32 series a
while ago.
I would add, for those that don't know, the Arduino ecosystem is
oriented towards being relatively easy and educational and such.
But when performance is important, it's better to use the MCU
chips "more directly", meaning (typically) code written in C,
using the vendor's development GUI (they all tend to be similar),
and taking advantage of the vendor's own driver libraries.?
Note that for nearly all applications, any of the major MCU
vendors can get the job done. They have dozens of chips, a bunch
of Eval Boards, code libraries, tutorials, etc.
I think that the STM32 series is good, but I've never used it.
Over the years I've implemented many dozens of apps for MCUs (in
my 'real job' and as a hobby), for a long time using Microchip
parts, then in more recent years T.I. Now retired, I still do a
lot of hobby projects using T.I. Tiva, MSP430, and MSP432 -series
parts. Any more, I always use an Eval board as the basis of the
HW. Most of the boards are less than US$20, have an on-board USB
programmer, have a bunch of 0.1" pins to connect to, and sometimes
other useful parts. I've made custom PCBs in the past, but it no
longer feels like a good investment of my time.
Pete
