I have a PixelViewTV pro and PVR-350. I also use the composite input on the PVR-350 where I need to change the channel externally to MythTV. I use the PVR-350 remote with LIRC (via the PVR-350) to navigate my way through MythTV on my TV. I also needed LIRC to use transmit to my external tuner.
From what I could read about LIRC, it does not support multiple devices (remote via PVR-350, transmitter via serial port) and I found myself a little frustrated that I could either use the remote or transmit to my external tuner. I had made a $5 transmitter job that worked fine and did not want to spend more since I knew this solution did work, just not with LIRC and multiple devices.
What I found with LIRC is that the Hauppauge PVR device uses the lirc_i2c kernel module and when I wanted to transmit via serial, lirc_serial was used. In LIRCs case it was using a char major of 61. So I copied the LIRC source to a different folder, searched and replaced 'lirc' and 'LIRC' with a different name (remote and REMOTE in this case), and replaced the char major 61 to another number (72 in my case). I then made and installed the devices etc as per usual, insmod remote_dev and remote_serial, started the new lircd (which is now remoted) and I was able to have a second remote control daemon to transmit to my external tuner. I have not tested this with multiple serial devices (on different ports) but I think this could work in this case also.
Hope this helps some of you guys out there. I don’t know if this will break anything but it works well on my system