I've gotten several requests to upgrade the sound of steamers from the Lionel RS4 boards to one of the ERR RS Commanders. In the past, I wired it up and it didn't recognize the serial data stream. I decided to take one more look, in theory it should be pretty easy, I have all the signals required right at the RS4 sound card connector!
I wired it all up, and sure enough, it worked great in conventional, but the command serial data wasn't recognized. Now I know that the RS4 board takes the same serial data as the ERR RS Commander, so there was something else in play. I fired up my 'scope and verified that there was a nice looking serial data stream on the proper connector pin, and I could even see the whistle command when I pressed the whistle on the remote. So, I connected the ERR board to the RS4 connector and monitored the serial data.
WOW, now the serial data went from a 0-5 volt signal to a 0-2 volt signal! Mystery solved, the AD-20 board doesn't have the drive to power the opto-isolator on the ERR RS Commander.
Gosh, I've just recently designed a little board to solve this problem, might as well apply my fix. Enter the serial port buffer that I recently posted about in these very pages.
Added that to boost the serial data stream and like magic, the command operation works! The good news is, there is a way to use the ERR RailSounds Commander with the wireless IR link for upgrades. I'm picking up some of the Lionel AD-20A boards for times when I'm starting from scratch.