2-pos to 3-pos dig converter advice

[wantAsummit]

I am looking for some advice on creating a 2-position to 3-position converter so that transmitters limited to 2-positions (such as the DX3S and DX3.0) can handle 3-position tasks (such as dig or rear-steer).

Electrically I won't have any issues, but I am looking for some advice on functionality. The converter will be in between the receiver and the 3-position accessory. The output will be capable of 3 different positions. Each position will be able to set up for any arbitrary position via potentiometers. So the way I see this working is be counting transitions between position 1 and position 2 on your transmitter. Here is where I need your advice: With radios that have digital trim buttons to handle positions 1 and 2, they normally return to a center position and it is difficult to identify what the last position selected was. If I define a transition as going from one position to the other and back again, this would solve the problem of not knowing where you were to start with.

So functionally I would count the transitions within a time period. After the time period, I would send the servo to its assigned position. You could have position 1 (the easiest to get to) be 4WD, position 2 be front Dig, and position 3 be rear Dig.

Do you guys think this is a reasonable approach?

I also have plans for a 3-postion to 3-true-position converter where position 2 doesn't need to be free wheel (on some other digs) or if your transmitter doesn't have EPA or trim adjustments.

Please vote here if you like the idea or have any suggestions:
http://www.rccrawler.com/forum/showthread.php?t=264496