Hey Bill just found your channel as I was searching for how to set up the IO Expander for DCC-EX. Your video was very clear and easy to follow. I get your point about using the PCA9685 for controlling LEDs. I was planning to go down the same route but also plug in a fast clock from DCC-EX to control LEDs with timed sequences. Hopefully it won't be too long before you produce the PCA9685 video... Where I see the DCC-EX EX-IOExpander coming into play would be for a control panel. I was looking at the idea of hooking up push buttons to it to drive switching of track routes on my planned layout. You could potentially use some PINS on the EX-IOEXpander for the buttons and others (or a PCA9685) to control LEDs on the control panel to feedback which route is set. If the layout is a decent size, it might even be possible to use multiple EX0IOExpanders configured identically (with different I2C addresses of course) to have several identical control panels located at different points around the layout for the use of multiple operators. Or indeed break down the control of the panels more locally on the layout as a form of signal box. It's really interesting technology. Best wishes from Sydney Australia, Jon
Hi Bill, I just found your video and it was most interesting, I am using MCP23017 devices to sense for Block Detection and I may have up to 8 of these devices on the I2C bus to the DCCEX Command Station, but as yet not at the stage of configuring, If you are Familiar with these devices I would be great if you could do a video ... the sense comes from a design of Diode voltage drop i.e the track is fed via 2 x 1N5819 diodes back to back and the voltage across the diodes goes through a LM339 comparator and is fed to an MCP23017 pin after a bit more logic ...Regards John
Why do you link the Megas together on the +5V lines, when they each have their own power supply? Why don't you link the Megas together on the GND lines to define a common ground plane?
I'm not set up to test that theory at present time, but I followed a diagram that was provided by the pros on the DCC-EX Facebook page at the time. Go ahead and try it that way and see what happens.
Hey Bill just found your channel as I was searching for how to set up the IO Expander for DCC-EX. Your video was very clear and easy to follow. I get your point about using the PCA9685 for controlling LEDs. I was planning to go down the same route but also plug in a fast clock from DCC-EX to control LEDs with timed sequences. Hopefully it won't be too long before you produce the PCA9685 video...
Where I see the DCC-EX EX-IOExpander coming into play would be for a control panel. I was looking at the idea of hooking up push buttons to it to drive switching of track routes on my planned layout. You could potentially use some PINS on the EX-IOEXpander for the buttons and others (or a PCA9685) to control LEDs on the control panel to feedback which route is set. If the layout is a decent size, it might even be possible to use multiple EX0IOExpanders configured identically (with different I2C addresses of course) to have several identical control panels located at different points around the layout for the use of multiple operators. Or indeed break down the control of the panels more locally on the layout as a form of signal box.
It's really interesting technology.
Best wishes from Sydney Australia,
Jon
Hi Bill, I just found your video and it was most interesting, I am using MCP23017 devices to sense for Block Detection and I may have up to 8 of these devices on the I2C bus to the DCCEX Command Station, but as yet not at the stage of configuring, If you are Familiar with these devices I would be great if you could do a video ... the sense comes from a design of Diode voltage drop i.e the track is fed via 2 x 1N5819 diodes back to back and the voltage across the diodes goes through a LM339 comparator and is fed to an MCP23017 pin after a bit more logic ...Regards John
Why do you link the Megas together on the +5V lines, when they each have their own power supply?
Why don't you link the Megas together on the GND lines to define a common ground plane?
I'm not set up to test that theory at present time, but I followed a diagram that was provided by the pros on the DCC-EX Facebook page at the time. Go ahead and try it that way and see what happens.