On Mon, Apr 7, 2008 at 11:16 AM, Giles Thomas <[EMAIL PROTECTED]> wrote:
> > On 02/04/2008, Rod Whitby <[EMAIL PROTECTED]> wrote: > > > Giles, it looks like you're really going to need a serial console to > debug this one ... > > What would I look for with a serial console? I assume that would give me > the console output and persist over a reboot, so perhaps I'm looking for > kernel panic messages or the like? > If so, I assume (as per < > http://www.nslu2-linux.org/wiki/HowTo/AddASerialPort>) that I'll need to > start doing a bit of hardware hacking to enable the internal serial port, is > that right? > > Regarding the serial port, I made my own, using a MAX3232 and bunch of caps/resistors on the NSLU2 itself (actually by superglueing the MAX3232 upside down and soldering the components to pins directly), then soldering the RS232 signals directly to a cable and hot-glue the whole thing behind the ethernet connector. I wouldn't suggest everyone do this. This is the datasheet for the MAX3232: http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1068 What you need is a TTL-to-RS232 converter. I don't know if the USB-to-serial adapters will work, as serial EIA232 is specified negative and positive voltages (single-ended not differential), whereby TTL is just 3.3V and ground. The MAX3232 has a charge pump to get the negative and positive voltages higher than VCC. Not sure if you can use something that's RS(EIA)422 capable. Googling for "TTL RS232" I saw these links: http://www.ecrater.com/product.php?pid=1750384 http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html Some of the prices for these things is extremely outrageous... $75-$200 I've seen. Ridiculous. I looked on ebay for "rs232 TTL" and saw several candidates. Just make sure the one you get will support 3.3V. The MAX232 is 5V and MAX3232 is 3.3V (what you need). It shouldn't cost more than $15, and that's being generous. Next, you'll need some way to interface this to the NSLU2 (see page you mention above). If you're good at soldering, I'd recommend some header test pins, 1x4, but I don't know the pin spacing (is it 0.1"? - if so someone please update the wiki - I don't have access to my NSLU2 right now to measure). Then you'll need to get some kind of female socket, 1x4 jacks, soldered to wire to the board you bought. Let us know what stage you feel comfortable attacking this console project. -Rob
