OutoSoft

Odd Software for Odd Jobs

minidisc

Replacement Sony MiniDisc remote, part 2

The RM-MZ3R MiniDisc remotes I ordered on eBay arrived today so I got to work pulling one apart to start figuring out how to emulate one so I could have a nice large control box rather than a fiddly little remote.

MD remote2

It's simply a bunch of resistors (and one capacitor), with the audio L/R channels passed through.

MB remote1

The audio uses three wires - ground (brown), left (white), right (red). The controls use two wires - grey (KEY) and yellow (+B). Two remaining wires were cut short and not terminated on the circuit board - these, I assume, are for the display information (the RM-MZ3R doesn't have a display).

The resistor values are:

  • R1 = 1KΩ
  • R2 = 1.3KΩ
  • R3 = 1.3KΩ
  • R4 = 47Ω
  • R5 = 1.5KΩ
  • R6 = 62Ω
  • R7 = 2KΩ
  • R8 = 1.3KΩ
  • R9 = 1.5KΩ
  • R10 = 2KΩ
  • R11 = 2.4KΩ
  • R12 = 2.4KΩ

There are ten switches:

  • S101 = hold switch
  • S102 = reverse, select left
  • S103 = FF, play, select right
  • S104 = pause, CAPS
  • S105 = stop, ENTER
  • S106 = VOL -
  • S107 = VOL +
  • S108 = TMARK
  • S109 = DELETE
  • S110 = EDIT

Various combinations of the resistors lead to the MD unit understanding what command was sent. This is what I'm working on now (yes, I can just find it on the Internet but I learn more this way).

To make it easier, I've removed the wires from the circuit board and replaced them with headers. I've also soldered the tiny wires onto a breadboard in preparation for tinkering with an Arduino. I used a hot glue gun to try to make the wires a bit more robust - let's see!

You can see the two shorter wires on the right - these are for the display information. Should be interesting to figure out how that works.

2016-02-15 20.32.23

I'm almost ready to start tinkering …

MD remote3

Project Idea: Replacement Sony MiniDisc remote

A project idea to exercise the brain - replace the RM-MC38EL remote control on my Sony MiniDisc recorder with a larger unit.

2016-02-01 06.47.07

It would use a larger and easier to read 16x2 LCD and buttons controlled by an Arduino. This will make it more like a component unit and make it easier to use in my workshop than the fiddly little controls it has now.

Sony never made a component HiMD.

The hardest bit will be the plug - either cannibalise a remote or somehow simulate it? Two pins are used to send commands to the MD (different resistance for each command) and the other two for sending data to the remote's display (will need to figure that out!). It does appear easy to acquire Sony RM-MZ3R remotes on eBay, giving me access to a source of the plugs. It would be nice to have just the four-pin plug, leaving the headphone socket free.

I did find a similar project that pre-dates Arduino. In this case it was to allow the use of infra-red remote controls.

Might turn out to be another dead-end ... but it is fun to experiment!