Monday, March 24, 2014

Stairville DJ-X 16, voided my warranty

The DJ-X 16 is a very basic DMX controller, which I used to test out DMX controlled (d'uh...) LED lights. I cannot recommend it, it lacks a lot of features, and the buttons/faders have a very flimsy feeling. Nevertheless: Because I was pondering if it was worthwhile to modify its firmware, I decided to void the warranty (yeah!) and here are few pictures documenting the insides of this device.

What I found pretty interesting is the fact that, even though I bought it new only a few months ago, and it's still being manufactured exactly like that, it uses pretty antique components, and is an all-through-hole PCB, not a single SMD to be found.

The main controller is a Atmel AT89C55WD, a 8051 compatible 8-bit microcontroller. It's meagre 256 bytes of internal RAM is extended by 8k of High-Speed (120ns...) SRAM. A 29EE010 EEPROM takes care of the 8051's lack of long-term memory. Everything else is 80s-style design, with a lot of 47hc's.

There's a second, smaller, PCB which is home of the SN57176 RS485 driver/receiver, an optocoupler (MIDI out/through), connectors and a 7805 voltage regulator. The flat-ribbon cable connecting this connection-PCB to the main board is nicely labeled on the silkscreen, very convenient.

K1    1   2  COM
K2    3   4  Audio2
K3    5   6  Audio1
k5    7   8  MIDI in
+5V   9  10  +5V
NC    11 12  MIDI through
GND   13 14  GND
+5V   15 16  +5V
NC    17 18  DMX out
+12V  19 20  +12V

From Chris’ Miscellanea

From Chris’ Miscellanea

From Chris’ Miscellanea

No comments: