I've been trying to get lirc working with a usb adapter I have for a
while, and so decided it might be easier to build the homebrew reciever
and use that.
I've got all the parts and assembled everything okay (using the
rswww.com reciever is1u60 - It's all I could get) and lirc seems to have
started using /dev/lirc/0 without any complaints, and loaded the right
Problem is, mode2 doesn't do anything, and I need help with the voltages
on my circuit, as I think they are wrong. Assuming all voltages relative
from ground, in normal operation (that is, mode2 is on, listening, but
I'm not sending any ir signals) the voltages are:
RTS (+) +8.08v
The Power to IR Reciever (after regulator) +4.94v
Now, if I point a remote control at the IR reciever and hold down one of
the buttons, the voltages change to
RTS (+) +7.96v
DCD (data) +3.39v
Now, this is showing that the data voltage has only dropped by 0.5v -
and I don't think this is enough to trigger a change in the serial port.
obviously something is going wrong.
Does anyone know how to get this working? Or what's stopping it from
From: Andreas Wenzel <andreas.wenzel@st...> - 2004-06-02 21:30:07
Nicholas Devenish wrote:
> Now, if I point a remote control at the IR reciever and hold down one of
> the buttons, the voltages change to
> Ground +0v
> RTS (+) +7.96v
> DCD (data) +3.39v
> Now, this is showing that the data voltage has only dropped by 0.5v -
> and I don't think this is enough to trigger a change in the serial port.
> obviously something is going wrong. [...]
While receiving data, the voltage on the DCD line switches very fast
between +5V and 0V, resting at +5V when the receiver is idle. Your
voltmeter is way too slow to follow those voltage swings, thus showing
you some kind of an averaged value.
Can you get your hands on an oscilloscope somehow? You should be able to
see nice rectangles with sharp edges while receiving data from the RC.
Did you check dmesg for error messages after loading the lirc_serial