motivation

Example: Two OBP40s are installed as display instruments. To achieve waterproofing, they are mounted behind a glass panel. An external keypad is required to operate both devices.

NMEA2000 wired keyboard, designed for permanent installation
The device should be waterproof.
Six buttons, like those on the OBP60, should be used.
The keys should be "real" keys that provide good haptic feedback and can be located by touch.
A key press optionally provides acoustic feedback.
The keyboard should be able to be dynamically paired with different target devices.
Configuration via a web interface
DIY-friendly

Quick Guide

The device consists of the following components

Status LED: this can assume different colors
Brightness sensor (from version 2 onwards)
Destination Display (DST): Shows which device the key presses should be sent to.
Destination selection button: To switch between the individual destinations (A, B or C)
Keys 1 to 6: Send a configurable key code to the destination.
M12 Micro-C connector: This is where the NMEA2000 cable is connected.

Installation

Connection to the NMEA2000 network
The device starts automatically; the status LED lights up red for informational purposes.
An internal test follows, in which all LEDs light up once.
Target A is selected, the corresponding LED is lit green.
The status LED flashes briefly once every 5 seconds.
If a temperature/humidity sensor is installed, it sends the measured values to the NMEA2000 network at regular intervals.

Configuration via web GUI

Connect to the Wi-Fi OBPKP61, password keypad61
Accessing the address 192.168.15.1
Accessing the page Config
Make the desired settings
Save, the device will restart automatically.

Three destinations can be configured for the key codes. The OBPkeypad 6/1 retrieves a list of devices present on the NMEA2000 network. These can be assigned to destinations A, B, and C. It is possible that not all or no devices will be displayed immediately after power-on. In this case, simply wait a while.

Configuration mode

To switch from normal operation to configuration mode, press and hold the destination button for more than 3 seconds. The status LED will light up blue after you release it. In this mode, buttons 1 through 6 each have a special function:

button	function
1	Day/night mode switching
2	Switch acoustic signals on/off
3	Access Point On/Off
4	-
5	Restart (reset) device
6	Put the device into deep sleep mode. Wake up by pressing the destination button

To exit configuration mode, press and hold the target selection key again for more than 3 seconds. When the status LED is no longer blue, the keypad is in normal mode.

Turn off

The OBPkeypad 6/1 is designed to be switched on and off using the NMEA2000 bus.

If it is not needed during operation, it can be put into deep sleep mode. To do this, switch to configuration mode and then press the button. 6 Press. The blue LED will flash to confirm, and then all indicators will turn off.

To restart, press the destination selection button once.

Development

hardware

electronics

Main and LED board, version 1.0

Based on a Waveshare ESP32-S3 Nano
- can be operated directly on 12V (6-21V input)
6 buttons (1 to 6)
+1 button for destination selection (DST)
3 LEDs for destination display (A, B, C)
1 RGB LED for status indication
1 buzzer for acoustic key feedback
NMEA2000 / CAN
- SN65HVD230 CAN transceiver module
- M12 Micro-C panel mount connector, pre-wired (su)
I²C slots
- 2x 4-pin socket strip
  - 1x Temperature / Humidity Sensor SHT31
  - 1x free
- 1x qwiic connector (3.3V; SMD)

casing

The current housing design is intended to be recessed into a surface. The raised edge all around is designed for this purpose. A watertight seal can be achieved using a surrounding sealant/adhesive. In this case, the screw connection is probably unnecessary. Alternatively, a foam rubber ring or similar material would also be conceivable.

The existing prototype is a 3D-printed (PLA) front and back panel. The front panel is three-colored: the base color of the casing, transparent for the LED cover, and black for the lettering. A fourth filament is required as support filament to cleanly print the 1mm round recess for the button seal.

All internal connections are made with M2.5 screws. In the final housing, the housing connection should be fitted with threaded inserts. M4 countersunk screws are provided for mounting the housing.

Sealing between the front and back is not actually necessary, however a silicone foam cord is provided between the housing halves.

software

PlatformIO is used, just like in the other OBP projects.
It is programmed in C++
License GPLv3
The device is a simple The device receives a newly developed firmware.
The web configuration interface is based on the operation of the OBP60/40.
Various types of keystrokes can be evaluated.
- Pressed briefly, for less than 1 second
- medium, pressed for between 1 and 3 seconds
- long, pressed for more than 3 seconds
There should be a day and night mode.

Project status

First prototype circuit boards have been manufactured (v1.0)
- There are still errors in the buzzer connection.
A printable case variant exists, printed on a Bambu Lab A1 mini.
A test firmware for the OBPkeypad 6/1 exists.
Firmware is actively under development and will be available soon.
- Several design decisions still need to be made.
On the receiving side, the remote button capability must be integrated into the standard OBP60.

outlook

Reduction of cable lengths by supplying ground to the keys via the LED board
Additional features
- Integrated brightness sensor
- The buzzer could be used to output NMEA2000 alarms.

Files/Links

Warning: This project is still in its early stages; changes may occur at short notice. Therefore, please always check the version number.

Firmware: Source code access available upon request
→ https://git.hoogi.de/thooge/OBPkp61

3D printing files: FreeCAD
→ https://www.hoogi.de/obp/OBPkeypad61.FCStd

Circuit board data: KiCAD
→ https://www.hoogi.de/obp/OBPkeypad61_PCB.zip

Have fun with the device!