May 6, 2013

It was necessary to add another CD4067BE multiplex chip to the board to accomodate additional analog inputs (faders and potentiometers). So the layout of the board had to be adjusted and additional wiring added.

Here is the new version of the board with PCB sockets and +5v/ground wires installed:

Board v 2.0

Multiplex chip wiring detail:

The large bundle of green wires send a binary digit to the pins, telling them which analog pin to read and send back to the microcontroller. Since the microcontroller sends the same data to each chip simultaneously, the wires can “daisy chain” off each other:


(It’s a little cluttered)

Here is a shot of the board with all wires connected. A single multiplex chip is seated in its socket. Along each edge are 2.54mm right angle pin headers. These pin headers are necessary to connect the analog inputs of each multiplex chip to an analog control (potentiometer).

Since there will be so many wired connections from the analog input pins of each multiplex chip, it is necessary to use the bottom of the board. Here, one chip is connected via jumper cables. (The other half of the chip is soldered to the board, directly connected to the right angle pin headers):

Here, two multiplex chips are wired to the right angle pin headers at the end of the board. The single wires running almost perpendicular bring analog data to the microcontroller:

The next post will contain more pictures of the final build, as well as a short video of some of the controls in action.