LIRCD can't detect remote

[coreywi]

I've got a RPi3 that I am trying to get to recognize signals from a RC-6/Windows media center remote with a TSOP38238 receiver. There are lots of HOWTO's scattered all over but they either refer to the old /etc/modules-based configuration, or they just did not work for me.

I keeping getting hung on the setup step getting the 'mode2 -d /dev/lirc0' command to detect anything (of course lircd is not running when I try this).

I have the IR receiver power pins wired to 3.3V and GND pins. The data pin is wired to GPIO physical pin 18 (BCM 24). I have an oscilloscope between GND and the data pin and I see pulses when I press a remote button. In idle state, the scope is reading about 1.98V. When I press a button, the pulses go from 1.98V to near 0V.

I verified the following line in my /boot/config.txt:

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# Uncomment this to enable the lirc-rpi module
dtoverlay=lirc-rpi

And dmesg seems to be happy (with the exception of the first line):

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pi@raspberrypi:~ $ dmesg | grep -i lirc
[    1.959740] systemd[1]: Cannot add dependency job for unit lircd-setup.service, ignoring: Unit lircd-setup.service failed to load: No such file or directory.
[    2.873137] lirc_dev: IR Remote Control driver registered, major 243
[    2.881714] lirc_rpi: module is from the staging directory, the quality is unknown, you have been warned.
[    3.934935] lirc_rpi: auto-detected active high receiver on GPIO pin 18
[    3.935269] lirc_rpi lirc_rpi: lirc_dev: driver lirc_rpi registered at minor = 0
[    3.935274] lirc_rpi: driver registered!

The modules appears to be loaded:

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pi@raspberrypi:/etc/lirc $ lsmod | grep lirc
lirc_dev               10583  1 lirc_rpi
lirc_rpi                9032  0

I thought the problem might be that perhaps the TSOP38238 is active low, not active high as the dmesg logs show, so I tried both of these (one at a time) in config.txt:

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dtoverlay=lirc-rpi,gpio_in_pin=18,gpio_in_pull=up
dtoverlay=lirc-rpi,gpio_in_pin=18,gpio_in_pull=down

But it did not appear to make any difference in 'mode2' showing something. Any help would be appreciated.

[Texas-Mark]

The data pin is wired to GPIO physical pin 18 (BCM 24)..

I think this is your problem as you are using GPIO (BCM) pin 18 in your config.txt Try using physical pin 12 for your data or change your config.txt to 24.

[coreywi]

Nice simple solution...thanks!

Darn differing pin numbering schemes!

[DougieLawson]

Nice simple solution...thanks!

Darn differing pin numbering schemes!

https://pinout.xyz fixes that nonsense.