NMEA 2000 KiCAD PCB and sketch for analog inputs (e.g. water level, fuel gauge, switch, etc ...)

Based on https://github.com/ttlappalainen/NMEA2000

Can be used to create a NMEA 2000 device like a sensor for fuel gauges. The board is easy to work with since it contains ISP and serial ports.

Use at your own risk. Don't forget the right external fuses, etc.

Prerequisites

• A NMEA2000 or Seatalk NG network
• PlatformIO CLI from https://platformio.org
• A PCB manufacturer of your choice and some SMD soldering experience

How to

PCB

Equip SMD parts for power (LDO, etc) first and measure input to output voltage carefully. Adjust R4 (and R3) resistors, if necessary. If voltage is around 4.8V - 5V, place other parts.

Burn bootloader

0. Disconnect PCB from other power sources or adapters.
1. Connect an AVR ISP programmer (usbasp) to ISP port
2. Change into arduino-blink directory and type pio run --target fuses. If the chip doesn't answer run avrdude manually with -B flag to set the bit clock rate, see https://electronics.stackexchange.com/questions/388324/avrdude-error-program-enable-target-doesnt-answer-1
3. Change into arduino-blink directory and type pio run --target bootloader
4. Optional: The sketch can be uploaded via ISP directly from arduino-sensor directory (pio run --target program)

Upload sketch

0. Disconnect PCB from other power sources or adapters.
1. Connect an USB serial adapter to serial port
2. Change into arduino-sensor directory
3. Run pio run --target upload

If errors appear during upload (e.g. programmer is out of sync or protocol error use another USB cable, USB hub or USB adapter. Check USB voltage (>4.89V) and ripple noise.

BOM

• Case: RND 455-00182 https://www.reichelt.de/kunststoffgehaeuse-115-x-65-x-40-mm-ip65-rnd-455-00182-p193396.html https://www.distrelec.de/Web/Downloads/_t/ds/RND_455-00182_30064403_mcd_eng_tds.pdf

• AVR: AT90CAN128 https://www.reichelt.de/atmel-ic-at-90can128-p55544.html

• Transceiver: MCP 2562-E/SN https://www.reichelt.de/bus-controller-1-treiber-1-empfaenger-so-8-mcp-2562-e-sn-p143745.html

• Connector: M12 Plug https://www.reichelt.de/sal-m12x1-5-pol-einbaustecker-sal12-fs50-p136981.html?&trstct=pol_38&nbc=1

• 12V to 5V: LDO https://cdn-reichelt.de/documents/datenblatt/A200/LT3010EMS8E5.pdf