Digital odometer with flash/RAM memory for car

[Peter]

Something close that is off the shelf

http://www.trailtechproducts.co.uk/store/erol.html#636x0&&http%3A%252F%
252Fwww.google.com%252Fsearch%3Fq%3DTrail+Tech+motorcycle+speedo%
26sourceid%3Die7%26rls%3Dcom.microsoft%3Aen-US%26ie%3Dutf8%26oe%3Dutf8

There are other models available for trail motorcycles.

 

[Alex Gibson]

"Gingre" <not@here.com> wrote in message
news:4674774a$1@dnews.tpgi.com.au...

Best time of the day. My record is 1am, normal is 3.30 am. Go to bed about
7.30pm though (and miss all that intelligent stuff on the TV...)

But at least the abc and others but some of the good stuff onto their
websites
like
http://www.abc.net.au/science/crude/

Alex

 

[Alex Gibson]

"princo coasters" <princo@makesgoodcoasters.com> wrote in message
news:467338f9$0$24918$afc38c87@news.optusnet.com.au...

Thanks for the replies.....

Yeah, I know i need to store the data across a few bytes, but therein lies
my problem - i have no idea how to do that.....

Any PIC'sperts who have some example code for storing large numbers in
EEPROM ?


Thankyou!

google piclist

You are not storing a single large number but a series of digits.

Pics and other similar chips are 8 bit so values per register
are 0 - 255 or 0 - FF in hex.

So use a register to store each digit (0 - 9).

For a long term solution I'd recommend storing the values into a serial
eeprom or other chip
on power off. A decent sized cap would give power for long enough to
write the latest value.

1. first step try the pic eprom

2. serial eeprom/flash chip attached to the pic

3. sd card - let you store a lot of other info as well

few circuits
http://www.gedanken.demon.co.uk/gps-sd-logger/
http://www.gedanken.demon.co.uk/thermometer-recorder/ for serial eeprom
circuit
http://www.techdesign.be/projects/020/020.htm

Doesn't have to be a pic , could use atmel avr or other micro.

Do you know any programming language ?

Dontronics.com sell some cheap pic boards(and avr and others) from olimex.

http://www.winpicprog.co.uk/pic_tutorial.htm is quite a nice tutorial using
asm.

http://www.microchipc.com/ examples for the hitech and microchip c
compilers for pics.

If you use an 18f or 24f or 30f pic , microchip have c compilers for them.

See 3rd and 2nd last projects on this page
http://www.microchipc.com/sourcecode/


Alex

 

[Gingre]

"Alex Gibson" <news@alxx.org> wrote in message
news:5djv6rF359epoU2@mid.individual.net...

.....
http://www.winpicprog.co.uk/pic_tutorial.htm is quite a nice tutorial
using asm.

Alex
What a pity about that speckled background, which makes it much harder to

read IMHO

 

[swanny]

"Gingre" <not@here.com> wrote in message
news:46738bcb@dnews.tpgi.com.au...

Can I query a piece of this, Swanny? Does that mean that my USB memory
key
has a limited life? ie 27 years once a day backups?

It will depend on the type of flash, however eeprom has a significantly higher
endurance than flash memory (several orders of magnitude).
I quoted the endurance (write cycle) figure for the flash and eeprom in the PIC
micro. The endurance of your memory stick and camera card may be the same, but
it also may be less. It is probably anticipated that you won't be writing to
this piece of hardware in 10 years time, let alone 27. Micros on the other hand
have a tendency to sit in a piece of equipment for a bit longer (20 or so years
in some cases).

Since the odometer value is only 3 bytes, it makes more sense to save it into
the on-board eeprom in the PIC.