[NTLK] MP2x00 Internal Interconnect Breakout
jake at allaboutjake.com
Tue Jan 13 18:21:11 EST 2015
>I will not use one of the dumb USB-to-RS232 converters, but instead use
>an LPC1347 CPU, which incidentally costs the same, but comes with an ARM
>Cortex MCU core running at 72 MHz. It has more than enough pins to
>connect to every pin on the connector, and more (much more) than enough
>power to handle USB and Ser1.
Cool idea. Bonus points if you can get the external clocking to work as
an option for really fast (2 megabit transfers). I would love to see
something better than 119200bps.
>It has *one* feature that made it my favorite: it can be programmed
>through the USB port alone without any special software.
I haven't used this specific LPC, but I have used the mbed, and it is very
nice. I think the 1347 is supported by the mbed toolchain as well.
>- fixing the timing bug that requires slowdown.exe on MSWindows
Interested to know more about this, since you've mentioned it before. I
guess I'm a Mac user and don't experience this? I thought that slowdown
helps in poorly coded desktop apps that use no-op loops to delay. The
delays are too quick on modern computers. But the USB-to-serial thing
should be communicating at a fixed baud rate, so I don't see why it would
be an issue for modern computers. Matched baud clocks even on faster
processors should communicate at the same speed. I guess I just don't
understand the issue, and I want to make sure I'm not missing something
that I should be concerned with.
>And finally for the crazy part. We have access to the otherwise unused
>serial port 3, so why not use it and add some functionality?
One crazy idea I had was to control a Si5351 clock generator and make an
overclocking "implant" that could be switched by serial command. In
theory, the Si5351 could be made to switch frequencies cleanly, without
glitching and causing a crash. With your custom timing, serial comms
could even be made to work at the odd baud rates you caused by
I'm still partial to the WiReach module.
(http://www.connectone.com/?page_id=3527) --especially if we could do
external clocking and ~2mbit speeds. An all-in-one dream of an internal
wifi card with USB would be damn sweet. The chip would be able to select
for USB or WiFi-PPP. I think the big constraint in this case is physical
space inside the case.
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