I2C interface for photocell sensor

[csshah]

I would like to interface a photocell sensor with pic18F8720 using i2c interface. I never used i2c, if somebody has code to read data using i2c for similar sensor application then it would be very useful to me.

thanks in advance

[kender]

In short. Hook up the analog output of your photocell to a suitable I2C A/D converter. If you post the part number for your photocell, I'll be able to give you a more detailed explanation.

Cheers,
Kender

[csshah]

hey
thanks for reply. it s actually a range finder by acroname. I wanted to measure relative distance using it. I am pasting the link to the page


[http://www.acroname.com/robotics/parts/R145-SRF08.html]


take care
cs[/url]

[Ttelmah]

Guess what. :-)
99% of it is already done for you!.
The key comes when you look at the data:
[http://www.robot-electronics.co.uk/htm/srf08tech.shtml]

Note the comment, that the unit behaves like the 24xx EEPROMs, except that the actual device address is different, and that the actual registers are 36 registers starting at address 0.
Complete drivers for the 24xx EEPROMs, are included with the CCS compiler, in the 'drivers' directory. Use the smallest and simplest (2401.c).
In this code, there are three locations where the value '0xA0' is used, and one where '0xA1' is used. Change these to the address of the device (0xE0, and E1 - the low 'bit' here signifies read/write control).
If you then try 'read_ext_eeprom(0)', you should get back the firmware revision of the unit.
If you try:

[csshah]

Hey Ttelmah

thanks a lot for ur help u made my life easier. I will try to do the way u suggested.

cheers
cs