This circuit would have to be in communication with the odometer of the vehicle. This is a difficulty if it is to be used on many types of vehicles. I would suggest a calculator program which would ask for the odometer reading and then extrapolate to the time that 3000 miles would occur.
The cheap altertantive would be a written value on the person's calendar that they would check every week.
Many newer U.S. cars, have a sensor that provides a pulse per rotation, it is used by the on-board computer for speed, where it measures time between pulses. This could also run to a large digital counter which would count up to a value, and trip a registered led or something if the count exceeded a value. The user could reset the counter when the oil is changed.
HI ..
Ok let me give you some quick thoughts of my own ..
This type of gadget doesn't really requires to be very accurate .. is just an aproximate value ...2700,3000 ,3200 .miles is ok ..
So why just not mesure the time that the engine is on and average that to miles . IS NOT NECESARY to measure ROTATION .. but instead it can be
how many hours is a person sitting on the driver's seat or how many hours is the engine running .. then take an average SPEED ..let's say 30 mph .. multiply that for the number of hours that the person has used the car and count till tou get your 3000 mark..
You could have 2 switches to set the AVERAGE SPEED ...
one seting will be 27mph ,another 30mph and another 35 and the last one 40 The setting will be required at installation .The user will evaluate how long he conmutes a day ... Well just a thought you know..
This idea won't work with travelling salesmen.! (or just add a traveling salesman setting =65
Part of the problem with any of these schemes is that the electronics in cars are very tamper proof. Your car warrant would be voided if you tampered with the electronics.
One way around this is to have a sensor in the engine compartment to detect the spark plug firing. This would be an inductive pickup. From this you can run to a counter.
I think that your problem is easiest than you suspect. When a car manufacturer state that
every 3000 miles you must change the oil, you will consider that such variable (distance)
is refered to an estimated time that the engine had been running, not at the distance as seems.
The main purpose for the oil replacement is to keep protected the engine against frictions, doesn´t matter
if the car has wheels or had made 2 miles.
I´m agree with eltonjohn idea, just count how many hours the engine had been running and multiply
by an estimated speed according with your target.
i think I can get the distance traveled by counting the # of pulses emit by my vss sensor (vehicle speed sensor). I think 1 pulse = 1 wheel revolution.
Many newer U.S. cars, have a sensor that provides a pulse per rotation, it is used by the on-board computer for speed, where it measures time between pulses. This could also run to a large digital counter which would count up to a value, and trip a registered led or something if the count exceeded a value. The user could reset the counter when the oil is changed.
This is what i'm going for. How would I go about storing the # of miles traveled in some kind of memory? Would an EEPROM do? What kind of counter would be big enough to count the huge number of revolution?
I find this site today and it's a lucky that now I'm doing a final task that I have to make a distance meter that (replacing) analog odometer in a car.
I place a sensor in dashboard inside a car then I use optocoupler to generate pulse that connected to interupt timer in micro controller.
Hi,...
In my country, this device is standard equipment of the vehicle, but it's for 1st grade passanger only. For others? until now not yet attached.
May be you will design counter reading device, but dont worry for new product generated (since 2000) VSS -Vehicle Speed Sensor has been used at medium grade vehicle, this is will make simplification for your idea.
For next step, calculate the pulse generating for one revolution of wheel, reference the 3.000 miles (this is like David90 idea), put it's in flash memory EEPROM 93CXX, etc joint with microcontroller and program it for signal proccesing unit and give the check lamp or buzzer signal to driver if the 3.000 miles occur.
Don't forget the facility for reset your counter.
I'm waiting your design...........................