Searching \ for 'I2C, what again!?' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: techref.massmind.org/techref/i2cs.htm?key=i2c
Search entire site for: 'I2C, what again!?'.

Truncated match.
PICList Thread
'I2C, what again!?'
2000\01\13@130549 by Terry A. Steen

flavicon
face
I have used I2C before, but not on the firmware level. I have a 16C74B that
I want to write to and read from a serial eeprom (24C01C). The PIC uses a
20MHz crystal for a clock. I planned to use the RC4 for SDA and RC3 for SCL
and let the chips hardware do some of my work for me. I hope to run this
thing at the 400KHz rate, so I have placed a 2K ohm pull up on these pins.
I have set the chip selects to zero on the eeprom by connecting them to
ground.

Okay, I hope that at this point, it should be simple. I just want to be
able to send an 8bit value to a 7 bit address on the eeprom and read it
back. Thats it... just random write and reads.

If you have a good snip for this, let me know. I was going to use some
ap-note code from pic, but didn't see any that use the hardware I2C, just
software... dunno, maybe I just didn't look in the right place.

Thanks in advance,
Terry
-----------------------------------------------------------------
Sent from the desk of:
Terry Allen Steen, EE              spam_OUTengineeringTakeThisOuTspammarinapower.com
332 McLaws Circle, Ste 111         757-258-8800 (Voice)
Williamsburg, Va   23185           757-258-8805 (FAX)
-----------------------------------------------------------------
!I AM A WHALE MAIL USER! If you have a large file to send, goto
   http://www.whalemail.com    send them to:   mplengineer
       Give me your account and I will use it also
-----------------------------------------------------------------
Visit our web-site: http://www.marinapower.com
-----------------------------------------------------------------

2000\01\14@021531 by Dr. Imre Bartfai

flavicon
face
On Thu, 13 Jan 2000, Terry A. Steen wrote:

> I have used I2C before, but not on the firmware level. I have a 16C74B that
> I want to write to and read from a serial eeprom (24C01C). The PIC uses a
> 20MHz crystal for a clock. I planned to use the RC4 for SDA and RC3 for SCL
> and let the chips hardware do some of my work for me. I hope to run this
--- [ snip ] ---

Hi,
I'm afraid, it won't go as the manual states: "The SSP module in I2C mode
fully implements all slave functions, " and master functions are hardly
supported. All applications I have ever seend does it by software. The one
exception I know the new 16F87x generation, where master mode is also
fully implemented, Mchip says.

I hope, this helps.

Regards,
Imre

2000\01\14@090236 by Terry A. Steen

flavicon
face
I am thinking you are correct. I sat down with the specs for the eeprom
(24C01C) and determined all the minimum times, equiv cycles, etc. I found a
posting to the PICLIST that looks like it has all the same cycles and times
as I determined, so I will see how it works. It was made for a different
memory and micro... so there's minor changes to be made.

At least I can use the pins I reserved to do manual I2C.

Terry

At 08:13 AM 1/14/2000 +0100, Dr. Imre Bartfai wrote:
{Quote hidden}

-----------------------------------------------------------------
Sent from the desk of:
Terry Allen Steen, EE              .....engineeringKILLspamspam@spam@marinapower.com
332 McLaws Circle, Ste 111         757-258-8800 (Voice)
Williamsburg, Va   23185           757-258-8805 (FAX)
-----------------------------------------------------------------
!I AM A WHALE MAIL USER! If you have a large file to send, goto
   http://www.whalemail.com    send them to:   mplengineer
       Give me your account and I will use it also
-----------------------------------------------------------------
Visit our web-site: http://www.marinapower.com
-----------------------------------------------------------------

2000\01\17@074642 by Mordred of Logris

picon face
> If you have a good snip for this, let me know. I was

If you are a beginner, like me, I suggest using a C
compiler (I use CCS, dunno if other compilers have the
same feature), because it will (probably) have library
functions for I2c and other famous protocols.

The ccs has buil-in funcitons for all i2c features.

=====
May the ground never receive thee ...
__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com

2000\01\17@092411 by Terry A. Steen

flavicon
face
I plan to use a compiler sometime, but only when I get sick of reinventing
everything in assembly. Got it working with the help of other PICLIST
members. You might give it a go just to see how to do it... not all that
tough, you just need to ensure you have good timming.

Terry

At 04:34 AM 1/17/2000 -0800, Mordred of Logris wrote:
{Quote hidden}

-----------------------------------------------------------------
Sent from the desk of:
Terry Allen Steen, EE              engineeringspamKILLspammarinapower.com
332 McLaws Circle, Ste 111         757-258-8800 (Voice)
Williamsburg, Va   23185           757-258-8805 (FAX)
-----------------------------------------------------------------
!I AM A WHALE MAIL USER! If you have a large file to send, goto
   http://www.whalemail.com    send them to:   mplengineer
       Give me your account and I will use it also
-----------------------------------------------------------------
Visit our web-site: http://www.marinapower.com
-----------------------------------------------------------------

More... (looser matching)
- Last day of these posts
- In 2000 , 2001 only
- Today
- New search...