Openplotter is a fantastic GPS plotter software for the raspberry pi. Its a raspian OS including a SignalK server, an open source day to handle NMEA 0183 and NMEA 2000 communication onboard.

In this instructable I will show how I build my plotter in singel box, waterproof style.

Supplies

You will need:

- Raspberry Pi 4

-GPS. First I worked with this: http://www.cqrobot.wiki/index.php/Raspberry_Pi_GP...

Its OK, but it needs an external antenna

But the L86 GPS-chip is much better. Now I run the montessiere HAT: https://shop.sailoog.com/openplotter/4-moitessier... This one also supports AIS!

- 12V to 5V converter: https://www.ebay.com/itm/DC-DC-Car-Charger-Conver...

- Arduino pro micro, important: you need the ATMega32U4 chip! This is for the keyboard/mouse control.

Buttons: you need waterproof buttons, I like these: https://www.ebay.com/itm/16mm-Anti-Vandal-Momenta...

Then you need a good box. I went with this one: https://www.ebay.com/itm/Waterproof-Electronic-Pr...

With this box you can squeeze in a 9" display. If you want a 10" (nice) you need to find another box.

Screen: You want a high quality screen with 1000nits so that it works outside in the sun. after lots of searching I got this one: https://www.alibaba.com/product-detail/Outdoor-lc...

Link goes to the 10", you can mail them and order other sizes.

You need a controlled board for the monitor. This one uses 12V in and HDMI in. connects with 50 pin TTL to the monitor: https://www.ebay.com/itm/LCD-TTL-LVDS-Controller-Board-HDMI-VGA-2AV-50PIN-for-VS-TY2662-V1-Driver-Board/264705464702?_trksid=p2485497.m4902.l9144

Also you will need glue and cables, wiring for the buttons.

For the Arduino you need an prototyp PCB, resistors and screw terminals.

I use self adhesive hook and loop fastener for all in-box-fixation.

Step 1: Build the Keyboard

The 32U4 chip can act as a usb keyboard or mouse. solder it on the pcb. connect the buttons as the sketch shows. the buttons are NO, normaly open, if open D-pin goes low. When closed, d-pin goes high.

code for Arduino you find here: https://github.com/ola667/plotter

D2 = Right arrow

D3 = Left arrow

D4= down

D5 = up

D6= zoom out

D7 =zoom in

D8 = follow

D9 = select keyboard or mouse

D2-D8 goes to buttons, D9 - this one goes to a switch

Note: my raspberry is set to Swedish keyboard. haven't tried US, maybe you need to change some ASCCI codes

Look at the "keyboard.write" in the code.

plug the keyboard to a computer and try out the keys.

Then plug it to the raspberry with a usb cable. should be acknowledged as a keyboard

Step 2: Work the Box

Make a hole for the screen. draw a square the same size as the glas of the screen. Drill a hole just inside each side of the square and use a jigsaw to saw it out.

Drill holes for the buttons. Intall the buttons. don't forget the gasket on the inside. you can lay som silicone from the outside for extra waterproofing.

install the screen with hook and loop. This makes it possible to re-fit the screen. it is hard to get it correct at first try.

When the display sits correct, waterproof it with butyl rubber tape from the outside. this is a magic compund, you can buy it from your local car glass workshop.

on the back of the screen I put the screen controller card and the arduino.