ARDUINO OLED YANMAR TACHO FIX

The YANMAR LCD tachometer display stopped working at approximately 200hrs. The tachometer is made by Siemens VDO and is used by most of the marine engine manufacturers - YANMAR, IZUZU, and VOLVO PENTA. The failure of the LCD display appears to be common, there are countless requests for help among the forums for a fix. The easiest would be to replace the tacho in its entirety, like for like. This route has three issues; loss of recorded hours, cost and the potential for the same failure. We discovered a post on Canalworld.net topic - 71195 which offered a cost effective solution and a potential upgrade. The modification utilises an ARDUINO ATMEGA328 chip, a small OLED screen and some free software. The primary reason for choosing this option is that the user is able to retain the hours recorded.

A later version of the fix / modification working on the original and with some additional instruction can be found from denMike's website, it offers slightly different programming - includes custom boot up screen and aerial font. We went with denMike's version - I liked these features.

The challenging part was the soldering, some of it is really small. It's also not a quick fix, if you choose this route; may I suggest having a couple of beers to hand.

Some of the smaller issues below:

The OLED display is slightly smaller than the VDO plastic aperture. This could have been fixed with insulting tape. (See illuminated strips either side of OLED screen, first photo)

Whilst removing the RPM needle I almost broke the motor (cracked the plastic housing) - The last method employed worked perfectly, two screwdrivers underneath the needle adjacent to each other.

Initially I connected as specified, the first ignition on worked, second time the OLED screen was pixilated and the third time illegible. I then tried using the Vin pin, and have had no further issue.

And my only request (wish) - Would it be possible to output the engine hours in NMEA 2000 PGN?