I've built the parallel port receiver/transmitter which has been posted
on the lirc homepage for ages.
It doesn't work - although I *really* am capable of building such an
easy piece of hardware. All the waveforms look fine, I did even
calibrate them with a frequency counter to the 65kHz/38kHz. Almost no
overshoot. Almost zero ripple voltage. The pinvalues can be read by a
short debugging-application which I wrote. It all appears to be fine.
LIRC doesn't think so, however. Upon insertion of the kernel module, it
complains about a "bad timer" and reports (very different from time to
time) something around 40 to 50kHz. The frequency, however, is 65kHz
(yes, I assured that - I even thought of capacitive coupling and did
measurements while the device was plugged in the PC).
Afterwards, "mode2" doesn't report a thing when I blink the remote -
although the connected TSOP1738 does trigger (and the trigger signals
also appear on the parport, I checked).
In total desperation, I even turned the frequency up to around 80kHz, so
the kernel reported 65kHz and shut up. Didn't help.
So - what else can be wrong here?