If you have a Parallel port you could use the I/O pins there to do BCD assuming the SM120 can do it (which it looks like it can). It only requires 4 lines to get 16 channels. To select a particular channel just set the line to the Binary equivalent. Line Line Line Line Channel 4 3 2 1 1 0 0 0 0 2 0 0 0 1 3 0 0 1 0 4 0 0 1 1 5 0 1 0 0 6 0 1 0 1 7 0 1 1 0 8 0 1 1 1 9 1 0 0 0 10 1 0 0 1 11 1 0 1 0 12 1 0 1 1 13 1 1 0 0 14 1 1 0 1 15 1 1 1 0 16 1 1 1 1 I do this with a commercial repeater controller and Kenwood TK-7180/8180 radios and it works great. Jamey Wright WR4JW From: app_rpt-users-bounces@ohnosec.org [mailto:app_rpt-users-bounces@ohnosec.org] On Behalf Of Skyler F Sent: Wednesday, June 10, 2015 8:53 AM To: app_rpt-users@ohnosec.org Subject: [App_rpt-users] Remote Bases with 16 channel radios? Has anybody ever created a remote base with a radio like the SM120 16 channel commercial radio? Would it be possible to use the URI to specify the channel I want to go to, for example, hooking a GPIO pin to the "channel -" button and hooking another to the "channel +" button? So if I am on channel 1 and want to go to 7, the GPIO for "chan +" would have to pulse 6 times. That wouldn't be very reliable probably because there is no confirmation that you are actually on the right channel, but this is how I would do it: When a channel change is requested, pulse 16 or more times on the "chan -" button to make sure it is on channel 1. Then count the + button up to the channel number you want to go to. That idea, however wouldn't work on the SM120 because going below channel 1 brings you back to 16. Another idea I have is put one channel on a frequency reference (maybe those 150mhz re-broadcasts of radio stations?) and then find the channel you want based on that reference. Another idea yet would be to use a few more GPIO pins to see which elements of the 7-segment displays are lit up and then make an estimate on which channel you currently are on. Any other ideas? 73 Skyler kd0whb