Maruti Suzuki alto car is a 800CC 3 cylinder engine car. it's a manual drive car , so i need to fix RPM meter for it because it doesn't come factory fitted RPM meter. So i have searched ebay and local market to find suitable one. unfortunately there is a no rpm meter for 3 cylinder. each rpm meter has 4 , 6 , 8 cylinder capacity levels. So here i have made custom RPM meter using Arduino based electronics,
Step 1: Components We Need
parts we need :
here i have not mention the parts we need for PCB etching.
Electronics parts :
Arduino nano board ( around $3 Ebay )
16x2 LCD ( $2)
2N3906 Transistor x 1
0.1 uF 25V capacitor x 1
0.1uF capacitor( code 104 ) x 1
LM 7805 regulator IC x 2 and heat sink
10K resistor x1
100Ohm resistor x 1
47K resistor x1
10K preset x 1
male and female pin headers
Step 2: Circuit Diagram & PCB
here i have attached a diagram and pcb design file. it was design using Dip trace software. i have attached pdf file to easy print. if not you need that software. you can connect this circuit to ignition on power line. so then meter was work only when you start your engine.
Step 3: ARDUINO Code
The Arduino code was to display large digits in a 16x2 display. i have customized code for my purpose. code was attached.before connect check the pin mapping on code. i have attached images of meter panel connector and its rpm signal wire.
Step 4: Finalizing
hope now you will create and test will work. now need to connect this circuit to car. for that we need to get rpm signal. In alto ( My one 2006 lxi ) has unused connection on its meter board. in my case i was realized why manufacturers not include the meter. because they plan to add rpm meter. thats why the send rpm data from ECU to meter panel.
Step 5: RPM METER TEST
Finally if you set up everything ok, then start your engine. yeah..
its work... if not double check you connections.. if need any help contact me. sorry for poor video quality. THANKS>>>>