[archat68]

Thanks guys for the encouragement and positive response.

The plus point is u dont need any calibration and being microcontroller based its very stable and accurate.

BTW any suggestion for the cabinet? the assembled PCB is of the size 3.5X2 inch. presently i'm using a transparent plastic box with black tape taped around it except the display window. it serves the purpose - but looks ugly. any idea about fabricating the case from acrylic sheet.

If sufficiently large members are interested in building the project i may talk to some dealer in my city for preparing the PCB in bulk and also can get the microcontroller programmed in bulk.

______
Arup

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[FONT=sans-serif][SIZE=2]Genius might be described as a supreme capacity for getting its possessors into trouble of all kinds - Samuel Butler
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[gd1418]

Earning bread n butter from Alchemy and doing physics experiments... Good man, good..

Originally Posted by archat68

Thanks guys for the encouragement and positive response.

If sufficiently large members are interested in building the project i may talk to some dealer in my city for preparing the PCB in bulk and also can get the microcontroller programmed in bulk.

______
Arup

[Sudipto-S-Team]

Arup
Congrats. Great project. If you want to know who fabricates acrylic sheets in Kolkata I can tell you.
Sudipto

[madan80]

Hi Arup, looks like a lovely D-I-Y. Anyways, how did you get the code for programming the controller? can you please share those details. I wouldn't mind attempting to build one myself!

[speedmiester]

awesome job due, i think ill get down to building one for myself for my zen.
thanks a lot for the links.
Keep it up

[low_bass_makker]

Originally Posted by archat68

BTW any suggestion for the cabinet? the assembled PCB is of the size 3.5X2 inch. presently i'm using a transparent plastic box with black tape taped around it except the display window. it serves the purpose - but looks ugly. any idea about fabricating the case from acrylic sheet.

indian site.

http://www.phoenixmecano.in/

the link might not be working right now but you can the enclousre here.

BOPLA liefert weltweit Kunststoff und Aluminium Gehäusesysteme und Folientastaturen

[archat68]

@Sudipto
please post the detail

@madan
please go through the link of electronics-lab provided by me in one of my earlier post. u'll get a rapidshare link which contains all required things.

[dinar]

it's easy it program the controller you will find this in most of the web sitess related to PIC microcontrollers. all u need is a computer with serial prot and couple of easy to get components.check this page you'll understand
My PIC Programmer An easy-to-build PIC programmer, based in the JDM. Uses the serial port. (10/24/2004).

[IMP]

Awesome DIY project, i am actually thinking of how do i go about it myself!!! How does it pickup the engine rpm from the engine? can someone please clarify? Post csme more details and pics please.

Heres a link to a similar project. Tachometer and Digital Dash

[dinar]

IMP ,I hope you know how these tach work....
u can use an optical sensor ie: an L.E.D. with an light dependent resistor on the timing pulley or any other pulley which is convenient to fix an led pointing at it as well as the L.D.R. so the the light is reflected onto the L.D.R. by the pulley mark a point on the pulley with white paint or any reflective material, so that the ldr gives a pulsed out put as the reflective material is rotates. the output of the ldr is the signal you are looking for.
or you can use the ignition system to get the pulsed signal it is directly proportional to the prm of the engine.
or you fabricate a dice with a slot oen in it and use the optical sensor mentioned above with led and ldr facing each other, mount this dice on any of the rotating shafts of the engine and when this rotate due to the slot there is a pulsed on off sequence in the lrd getting exposed to light from led . the output is the signal.
I hope I have provided ans to your question. let me know if you need any more info.

[archat68]

Originally Posted by archat68

You get the input from either low voltage input at the ignition coil or from your ECU (it connects where a normal tacho connects in a car).
Here is the link for another forum where it was posted on my request:
Electronics Lab - Community

here u go

_______
Arup

[Sudipto-S-Team]

Archat
For acrylic sheet fabrication you could either go to Chhatawala Gali (behind Poddar Court) in Central Calcutta where you will find quite a few small shops doing it. Alternatively, there is a gentleman near Deshapriya Park who does it.
If both of these sound too far (I don't know where you stay), ask your neighbourhood aquarium shop. The hoods they sell are done by acrylic sheet fabricators.
Sudipto

[archat68]

Thanks Sudipto. I'll give it a try.

OT I stay near tollygaunge. Where do u?

@IMP, the project you've mentioned is nice. one con is it uses PIC18 Microcontrollers which is a bit costly and also programmers are not that easy to build. I've built a JDM based PIC programmer which costed me 300 bucks (excluding the cable) - costliest part of that was the 40 pin ZIF socket which costed me 200 bucks.
here it is:


There are other tacho circuits in the web too. Siliconchip has another one:
Silicon Chip Online - LED Tachometer With Dual Displays, Pt.1
quite nice but the display driver ICs are not available in kolkata and also manufacturer is not providing free samples.

Another one is Josepino tachometer (search for Josepino tachometer in google) - i built this one first - but very unstable in the noisy car environment. So dropped that.

Another one. original page is in german. here is the translated version:
LED tachometer
I didn't try it.

As i had said earlier the toughest part is the PCB fabrication. I had to built the same circuit thrice and had to built 3 sets of PCBs before i finally succeeded. In the first two there was some invisible defects (like short or cut) in the copper track. the 3rd was perfect.

__________
Arup

[IMP]

@Arup: The project i mentioned uses the PICAXE 18 microcontroller, these mc's are easily programmed directly via a serial cable, one just needs to connect 3 pins of the mc to the correct serial port pins. No need of programmers. But availability of picaxe in India may be a problem.

BTW which microcontroller did you use? is it a PIC16?

Great job on the Programmer there, which PIC's are compatible with it?

Regarding your tacho showing half of the actual rpm, i think, you can easily change that by just minor changes in the programming.

I must add that because of your project, i got interested, and found out a lot of info about microcontrollers and electronics over the net. I was a complete noob two days back, but today i know enough to start my own little "hello world" project using a microcontroller.

Cheers,
IMP.

[xinome]

this is too hightech for me, but seriously aweosme D.I.Y.