P-DMX 25-pixel / 5-servo controller (APC718)

David_AVD

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Recently I designed a small controller with P-DMX (power + DMX over CAT5) input that can drive 25x 5V pixels or alternatively 5x 5V small R/C servos. The development thread is here.




Features:
  • Compact size 50.8mm x 50.8mm (2" x 2")
  • 3mm mounting hole in each corner
  • P-DMX in/loop via 2x RJ45 sockets
  • 2 way terminal block for alternative DC input
  • Jumper to disconnect P-DMX power
  • Current overload protection
  • Jumper for DMX termination
  • Socketed MAX485 chip
  • On-board 5V 1.5A regulator to power 25 pixels
  • 12V - 35V input voltage range
  • 4 way plug-in pixel connector
  • 5x 3 pin headers for servos (not shown in picture)
  • DIP switch for address & 2801/6803 mode select
  • Status LED
There is a P-DMX distributor (hub) PCB coming soon that mixes power and DMX into CAT5 cables. You can use the APC718 boards with a standard DMX input as well of course and connect the power to the terminal block instead.

The same board can be used for 25-pixel or 5-servo mode. It's just a matter of using a PicKit to load the correct firmware. I will pre-load the version you want before sending out. I've only made up an initial batch of 10, but more will be available soon. ACL member price is $33 including GST.

These boards can be found on the AVD web site here.
 

David_AVD

Really old (now a Grandpa)
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I noticed yesterday that I goofed with the screen printing on the APC718 boards. The 0V and +5 texts next to the 4 pin pixel output connector are transposed. The connector was originally the other way around and I must have forgotten to finish moving the text. :-[

The actual pinout is correct and the same as the J1SYS boards. It's only an issue if you follow what's written on the PCB when wiring up the plug. I will blot out the +5 and 0V text on the boards that go out from now on. I had 100 boards with the error, so we'll just have to deal with it. Sorry about that!
 

David_AVD

Really old (now a Grandpa)
Community project designer
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For the servo code, I went with the suggested pulse timing range from the great Interwebs. I'm not sure how easy it would be to fiddle the numbers (in code) to use with 180° servos.
 
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