Hardware Installation

Mechanical

Location

NEX-FD is a miniaturized board intended to be installed in-wire: it is not mounted on the structure of the platform inside a box, but integrated in the harness itself, as one more element of the wire run. It should be placed as close as possible to the device it controls, in order to keep the RS232/RS485, I2C, GPIO, PWM or ADC wires as short as possible.

Protection

It is recommended to protect the board, either by covering it with heat-shrink tubing or by installing it in a protected location.

Electrical

Power

NEX-FD is supplied with 5 V through the primary pads.

Pinout

Primary pads:

Pad	Signal	Description
1	CAN-H	CAN bus, high line
2	CAN-L	CAN bus, low line
3	GND	Ground
4	5 V	5 V power supply
5	GND	Ground

Secondary pads:

The 8 secondary pads are shared by three independent interfaces: the serial port (pads 1 to 4), the I2C bus, GPIO, PWM outputs (pads 6 and 7) and the analog input (ADC) (pad 8). Pad 5 is the common ground for all the interfaces.

Serial port pads:

Pads 1 to 4 are shared by the RS232 and RS485 interfaces, so only the signals of the configured interface are available.

Pad	RS232 configuration	RS485 configuration
1	Tx 1 (transmission, RS232 1)	OUT-H (transmission, high line)
2	Tx 2 (transmission, RS232 2)	OUT-L (transmission, low line)
3	Rx 1 (reception, RS232 1)	IN-H (reception, high line)
4	Rx 2 (reception, RS232 2)	IN-L (reception, low line)

Ground pad:

Pad 5 is the GND reference, common to the all the secondary pads.

I2C and PWM pads:

Pads 6 and 7 are shared by the I2C bus, the GPIO and the PWM outputs, so only the signals of the configured interface are available:

Pad	I2C configuration	PWM / GPIO configuration
6	SCL (clock)	PWM 1 / GPIO 1
7	SDA (data)	PWM 2 / GPIO 2

ADC pad:

Pad 8 is used for the analog input (ADC).

Pad	Signal	Description
8	ADC	Analog Digital Converter, up to 5 V

Harness

The wires are soldered directly to the pads of the board, as no mating connector is used.