Software I2C

hmnrobots · Joined: 02 Oct 2009 Posts: 11

Hi Sorry cause I originally post in the code library forum;
my question is : Is it possible to built a software I2C slave on a chip that doesn't have any hardware I2C; From the forum, the slave code that read data uses the hardware interrupt to detect that the master is sending data or requesting data.
Am I clear ?

hmnrobots · Joined: 02 Oct 2009 Posts: 11

to complete : Is it possible to establish I2C communication between 2 non equipped I2C devices such as the 12F629 ? one master and one (may be more but at least one ) slave that would be able to respond to master questions ?

rnielsen · Joined: 23 Sep 2003 Posts: 852 Location: Utah

I've never tried it but I do know that it would be EXTREMELY difficult to do. Most of the PICs time would be dedicated to just looking for the correct bus signals.

Ronald

hmnrobots · Joined: 02 Oct 2009 Posts: 11

I just found this project of I2C to RS232 interface
. Coded in assembler : too hard for me !I thought It would be possible with C, don't you ?http://www.gedanken.demon.co.uk/rs232-converters/i2c.html

hmnrobots · Joined: 02 Oct 2009 Posts: 11

In fact none of these are able to act as a slave on a device without hardware!I ve got to take another PIC

bkamen · Posted: Fri Oct 02, 2009 11:35 am

Why would you convert I2C to RS232?

You haven't told us enough about the project -- but in any case consider this:

You need to research I2C and RS232 to learn the pros and cons of both.

Can you talk I2C to a pic that doesn't understand it? I think you can answer this question already (think: can you [spam] in a language to someone else who doesn't understand it? No.)

So once the receiving (slave) PIC understands I2C, is it better to run RS232 -- well that depends! (see above)

There are companies that make I2C -> RS232 "adapters" -- but if you want to control more than one device from a single master, I2C lends itself more to this kind of operation than RS232.

Again -- do your homework.

-Ben
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D

hmnrobots · Joined: 02 Oct 2009 Posts: 11

I was in fact thinking of an interface I2C/ RS 232 because my project uses already an I2C bus and I'd like to add a HF transceiver, but the one I'd like to use uses TTL RS232. It would be simplier to add another RS232/RS 232 but would use 2 other pins.

bkamen · Posted: Fri Oct 02, 2009 12:08 pm

In that case, use a PIC with multiple UARTS.

The 18FxxJ11 is very nice.

-Ben
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D