YAPP - home made diesel tacho

[AngusMcDoon]

Yet Another Pointless Project

This is just an update really of a previous bout of pointlessness, but I've had requests to do it, so here it is. The previous tacho/hour meter worked by detecting a spark to calculate engine speed. No good for a diesel, so I have modified the previous one to use a magnet and Hall sensor. Actually, it's two magnets placed in opposite polarity direction, because that's the way my Hall sensor works.

Speed is measured and displayed as well as time running. The time is only incremented when there is speed. The total time is saved in the EEPROM memory on the chip so that it is remembered over power cycles. I've used a smaller display than last time, but it shows everything needed.

I have stuck 2 small magnets on the flywheel of my outboard. They really are tiny. The Hall sensor is lashed in place in an appropriately Heath Robinson manner and connected with a dodgy connector.

Usual plate of spaghetti of brown wires. Processor is a PIC16F88. Total cost of components is under a tenner.

Sauce code and schematic (when I've drawn it) to anyone interested. All the components (apart from the magnets - EBay) came from Farnell and they are all chunky legged things so easy to make up on Veroboard.

 

[mersey]

Great work.

Any chance of making it work on the basis of a pulse in the fuel injector line, like TinyTach does?

I'm nothing against a Hall sensor, my car has one in it's electronic ignition, but just not practical to go on the flywheel on the application I'm looking at.

Thanks.

 

[AngusMcDoon]

Any chance of making it work on the basis of a pulse in the fuel injector line, like TinyTach does?

http://www.ybw.com/forums/showthread.php?t=277354

Recursive YAPPs .

 

[ctva]

Very tempted to try becomming a YAPPy person....

 

[fishermantwo]

On my fishing vessel with a 6LW Gardner main I used a pushbike speedo. One of those electronic doo dads. Magnet and sender mounted on front pulley. Speedo set to 24 inch wheel and kilometres. Very accurate except one decimal place out. Tried it again with my yacht motor with a newer speedo unit had had no joy.

 

[lw395]

Very neat diesel outboard you've built there!

 

[ProDave]

Slight fred drift, but for anyone looking at pointless projects, I am a fan of the Arduino microcontroller.

You can buy an Arduino nano for under £10 on ebay and that's a complete micro controller with support chips, memory, eeprom etc on a single tiny board, and the programming software is a c like language. the software to program it is a free download.

Sory for the fred drift but I thought it worth mentioning.

 

[AngusMcDoon]

Slight fred drift, but for anyone looking at pointless projects, I am a fan of the Arduino microcontroller.

You can buy an Arduino nano for under £10 on ebay and that's a complete micro controller with support chips, memory, eeprom etc on a single tiny board, and the programming software is a c like language. the software to program it is a free download.

I am moving on and up from PICs, starting today, but not to Arduino. I am starting to use STM32 ARM based processors. These are all surface mount and hence need to be bought already mounted on a dev board, but ST do their Discovery range which all seem to be about a tenner irrespective of which processor they have. They also include an ST-Link debugger hardware on the board.

I've just got the same LCD display as used in this YAPP going using the GCC compiler, Coocox IDE, and the CoOs RTOS...

Yesterday's YAPP is now just background dust.

 

[nigelmercier]

Sauce code ...

Does this have brown-out detection then?

Not at all pointless, I built a tachometer/hours running meter into my fuel gauge, now being redesigned with a new LCD.