Links:   Robert Cote   - designer of controller.
         MERG - excellent collection of train projects, and particularly DCC projects.
Contact me at: davidplattharris@hotmail.com
 
 

Here is latest hex code for MiniDCC.  NB it is for the 16F628.   628dcc16.hex
Here is a preliminary manual:  DCC_Ministation2.doc
If you need help, email me at dpharris@telus.net

Here is Johnny's circuit board with a 628 installed. (click on pictures to expand them)	Here is my lashed together MiniDCC 2, note the three ush buttons, the code needed these at one time but is now written so it only needs the two.

Radio Throttle
First pass at the circuits.

This is the transmitter schematic.  The HT12E encodes the 4 buttons into a repeated signal.  I have connected it so it transmits continuously, but we could configure it to transmit only when a button is pushed.	The transmitter circuit board.  Double sided, with the buttons on the bottom.  This can be powered by a 9V battery.  Would make a nice small package.
This is the receiver circuit.  The receiver module feeds the decoder (HT12D), which decodes the transmitted signal (repeated three times).  This in turn feeds the 4066, which is hooked in parallel to the buttons on one row of the MiniDCC.  NOTE: the receiver requires 4.5-5.5V, so DON'T USE 9V.	The receiver circuit board.  Needs to be modified to be compatible with the MiniDCC keyboard connector, so it can be plugged into it, and the keboard plugged into this board.  Power connections need to be defined.

Working prototypes, this is the receiver hooked to the keyboard cable - the MiniDCC keyboard is disabled because of this.	This is the transmitter prototype.  The green wire is the antenna (hi-tech).

These are some preliminary pictures of MiniDCC and booster.

This is the Cote controller,  with the booster on the left.	This is the controller opened, at the top is the LCD display, under that the keyboard, and to the left the PIC microchip on a circuit board with a telephone RJ-11.
This is a close up of my initial booster.  It consists of a L298, a diode bridge, a 7404, and a phone jack.	This is the reversing-loop contoller.  It consists of a dual coil latching relay and some diodes! (click to expand).
Here are two views of my booster using the 18200 chip.  here is also a dual oneshot to disable the booster in the absence of DCC, or in an overcurrent situation.  In the left picture: on the left there are two track clips and and the power supply connection; on the right there are two telephone sockets and two indicator lights.  (click a picture to expand it)
	A close-up of the DCC input end via 2 phone sockets.  The yellow LED is an over-temperature warning light, the red LED is a 'Dysfunction' warning, indicating either loss of DCC or shutdown for a overcurrent condition.  The booster restarts after a short delay of about 4 seconds.

Links:   Robert Cote   - designer of controller.
         MERG - excellent collection of train projects, and particularly DCC projects.
Contact me at: davidplattharris@hotmail.com