Never worked with an LPC ARM but happy to do some code review
Thanks, I haven't either but it just seemed like the right chip and it's something I've wanted to use for a while now.
Will it be the MBED processor ?
No, I just can't get my head around that IDE over the web thing, having to be connected to do development just doesn't make sense to me. The Mbed uses a 1768 which is very similar to the 178x I plan to use, so close in fact that I thought I would use the Mbed to prototype code, but then there's that "IDE over the web thing" and as far as I can see there's no provision for doing it any other way.
However if you want to get into them and also want to contribute to this I see no reason code can't be easily ported to/from the Mbed and the 178x.
I might get a couple of LPC Xpresso dev boards. They are only $30 and you get the free IDE (a real IDE based on Eclipse). I've already downloaded the IDE and played with some sample code, it works great.
Is that fast enough to look at something like I2C and determine that smaller pullup resistors are needed?
Hmm, generally I'd say no as the 400kHz sample rate is the same as the typical i2c bit rate and with analogue sampling you typically want to sample at about 10x the frequency of the data you are sampling.
However, doing this might work as you really aren't interested in the waveform per se, just whether or not the signal is being pulled low enough. So if the samples were taken at the right moment the viewed waveform would probably look like some form of triangle wave but the highs and lows should be the voltage on the line at that time.
So the short answer is that it should work in a fashion.
The 400kHz is the max rate the chip can read, so there's not much to be done about that without an external ADC feeding into the digital channels.
Logic analyzer - will that use the system's 8 or 16 MHz clock as the sampling rate clock? Or an independent source from the LPC ARM?
Currently I plan for the sampling to be run with an internal clock (timing mode), as to how fast I don't know yet but 20-40MHz should be doable (all I can work on is the data sheet at present, I have no experience with these chips). It may also be possible to use an external clock (state mode), I'll look into it.
Rob