Hi,
I would like experts to review the ARM7 development board by ENTESLA. I would
like to recommend this board to people interested in working on the ARM7
architecture.
ARM7 development Board... http://bit.ly/lq11KM
--
Stopazk
Review on ARM7 development board by ENTESLA
Started by ●June 17, 2011
Reply by ●June 17, 20112011-06-17
Your power-supply schematic seems to show a (schottky) diode between
the output of your 7805 regulator (with its associated decoupling
capacitors) and what you label as the +5V line.
A schottky diode typically drops 0.3 V.
Does this mean that what you label as a 5V line is actually 4.7 V?
This would cause difficulty and confusion, precisely what is NOT wanted for a demo board.
The 3.3 V regulator is powered off your "5V" (i.e. 4.7 V) line.
You do not show any decoupling capacitors at its input
(because the diode is in the way).
If there are none then you risk instability / poor regulation
with this regulator.
----
Your documentation comes as pdf.
You have encoded your pdf to request full-screen.
Why?
This will annoy many users who only have the one screen and have
to juggle the documentation and their development environment.
Also you have not provided the appropriate links so one can click on
a line from the table-of-contents and jump to the appropriate page.
----
I note that you do not provide any level-shifting / protection on
your "ISP" pin of the RS232-0 connector. This risks damaging the lpc2148.
There might be other problems.
But I would have to ask why pick the lpc2148 now?
Although it's a great chip for many projects, there are many newer
chips where people would be looking for a demo board.
Hope this helps,
Danish
the output of your 7805 regulator (with its associated decoupling
capacitors) and what you label as the +5V line.
A schottky diode typically drops 0.3 V.
Does this mean that what you label as a 5V line is actually 4.7 V?
This would cause difficulty and confusion, precisely what is NOT wanted for a demo board.
The 3.3 V regulator is powered off your "5V" (i.e. 4.7 V) line.
You do not show any decoupling capacitors at its input
(because the diode is in the way).
If there are none then you risk instability / poor regulation
with this regulator.
----
Your documentation comes as pdf.
You have encoded your pdf to request full-screen.
Why?
This will annoy many users who only have the one screen and have
to juggle the documentation and their development environment.
Also you have not provided the appropriate links so one can click on
a line from the table-of-contents and jump to the appropriate page.
----
I note that you do not provide any level-shifting / protection on
your "ISP" pin of the RS232-0 connector. This risks damaging the lpc2148.
There might be other problems.
But I would have to ask why pick the lpc2148 now?
Although it's a great chip for many projects, there are many newer
chips where people would be looking for a demo board.
Hope this helps,
Danish
