New Remote Control

(radio and/or Wired)

August 31, 2019

My new Remote Control box for the F7, Tender, NB1, and Mikado (in Push mode).

Wired versions have a 4-wire full-duplex UART interface operating at 9600 baud.
The transmitter sends out 2-byte packets every 1/37 seconds for the 12 inputs.
The LED display updates when a single byte is received from the controller.

Note: Some switches are dual function. So 8 switches provide 12 inputs.

Internally there is a stack of two circuit boards. The switch/LED board,
and a cheap CPLD board that provides the logic functions.

Radio versions include an RFM69 radio module missing from this board as well as
a battery control IC that is also missing. Wired versions don't need a battery.

The switch/radio board simply plugs onto the CPLD board.


The Apply/Release and the Forward/Reverse switches are momentary center-off.
The switches for Number board lights, Classification lights, Service lights, and
Train line are just simple on-off switches.
The Headlight switch is center-off and in the low position operates the Mars light.
The Bell switch is center-off, but is momentary in the low position for the Horn.

LEDs are left-to-right, Red, Orange, Yellow, Green, Blue, and Violet, and indicate
High-Current, Dynamic Braking, Low Battery Voltage, Forward, Reverse, and Standby.

Note: The ribbon wire seen here is only conveying 4 lines: +3.3v, GND, RX, and TX.

The CPLD board can be purchased from places like Amazon. The other board is custom
and is generally not available.