The NceCabBus library allows you to interface to a NCE Cab Bus via an RS485 Interface and provides examples that implement the following devices:
- Throttle with a 128x32 Pixel OLED Display, a 4x4 Keypad and a Potentiometer Speed knob
- Auxiliary Input Unit (AIU)
- FastClock that outputs the time to the Arduino Serial Port.
The library does not provide the actual RS485 interface - it only provides the logic to process NCE Cab Bus messages, however the examples show a simple connection to a common RS485 chip and drive the TX Enable directly.
ASCII schematic of connecting a half-duplex RS485 transceiver e.g. MAX487CSA+ to a microcontroller. Note: the /RE & TE pins on the RS485 chip are connected together and connect to the Arduino pin defined by RS485_TX_ENABLE_PIN in the examples
----+
|
AVR | /|
| / | A
| / +-------+
| RO / | |
RX +-------------+ | |
| \ | B |
| /RE o o---+ *-------------- RS485 A/+ Cab Bus Pin 3
| |\ | | |
| | \| | |
TE +---------------* | |
| | | |
| |\| | |
| | + TE | |
| | \ B | |
| DI | o----*---|-------------- RS485 B/- Cab Bus Pin 4
TX +-------------+ \ |
| | + |
| | / A |
| | +--------+
| | /
| |/
|
GND +--------------------------------------------------- Cab Bus Pin 2
|
----+
Paul Hardey has compiled and documented many helpful USB Interface and CabBus Commands and Responses into an Excel Spreadsheet here
These two pictures show how you can build your own RS485 interface with a bit of Strip-board and a RS485 chip to get started with interfacing to a NCE Cab Bus
