I've heard of other trouble with the parallel port adapters (i2c-pport and pcf-epp), I don't know if it's the driver or the hardware that is the trouble. I wouldn't want to debug it without a good 'scope. Anything else is going to be quite frustrating. Good luck. David wrote: > I don't know if I can do that without a storage CRO. I tried altering my > triggering but can't seem to hold the signal still long enough to actually > see it. > > Don't know if I can sample using my soundcard. I might be able to record > (dpending on whether the pport bus runs at less than 20Khz in speed. > > I then need to find an audio application that will display the waveform in > scope mode. > > Am I missing something or is this my next step? > > > On Thursday 20 February 2003 12:14, Mark D. Studebaker wrote: > >>you can try i2cdump 0 0 0x20 >>then look on the scope. >>If the chip is not responding you will see only the chip address and the >>register address >>(2 bytes for each access) >>If the chip is responding you will see the 3rd byte on the bus (the chip >>response) >> >>David wrote: >> >>>Hi, >>> >>>I am trying to get a PCF8591 and a PCF8574 working using the i2c-pport >>>adaptor. >>> >>>I have at the moment the i2c-pport and algo-bit modules loaded and am >>>trying to get access to the PCF chips. >>> >>>modprobe pcf8574 >>>modprobe pcf8591 >>>AND >>>modprobe pcf8574 probe=0,0x20 >>>modprobe pcf8591 probe=0,0x48 >>> >>>don't actually creaate any files under proc and the modules remain unused >>>as far as lsmod is concerned. >>> >>>I can get the devices up if I >>>modprobe pcf8574 force_pcf8574=0,0x20 >>>modprobe pcf8591 force_pcf8591=0,0x48 >>> >>>everything loads, I get the relavent files under >>>/proc/sys/dev/sensors >>> >>>it doesn't look like I am really taking to the chips though. >>> >>>Changes I make on the inputs aren't reflected in the values under /proc. >>> >>>If I run the i2cdetect 0 I get UU showing in both 0x20 and 0x48 >>> >>>I have used my scope and know that signals are getting to the chips in >>>question but it isn't a storage scope so I can't look to see if the >>>pulses are really valid i2c pulses. >>> >>>Any hints on what to do next. >>> >>>-- >>>Best Regards, >>> >>>David Price > >
