![](templates/subSilver/images/CCSLogo.jpg) |
![CCS C Software and Maintenance Offers](templates/subSilver/images/forumAd6.jpg) |
View previous topic :: View next topic |
Author |
Message |
lguancho
Joined: 08 Sep 2003 Posts: 5
|
Change I2C Master to I2C Slave On the Fly |
Posted: Wed Apr 06, 2005 4:40 am |
|
|
Hi,all. I have an application requirement on a PIC18F452 board. This board using a IO pin[defined as #define MASTER_I2C input(PIN_B3)] to determine whether it should be a I2C master or I2C slave.
Code: |
int1 Check_Mode(Void)
{
if (MASTER_I2C)
{
Master_Flag=TRUE;
#use i2c(master, sda=PIN_C4, scl=PIN_C3,FORCE_HW)
//InitI2C();
}
else
{
Master_Flag=FALSE;
#use i2c(slave, sda=PIN_C4, scl=PIN_C3,address=0x90,FORCE_HW) // Default Base Address
get_i2c_slave_addr(); // return my_slave_addr
SSPADD = my_slave_addr;
InitI2C();
enable_interrupts(int_ssp);
}
return(Master_Flag)
}
|
I called the check_mode() in my main code, before the loop. For testing, I enable the board for master mode. I just do a series of I2c_start(), i2cwrite(Data1)
,i2c_write(data2), i2c_stop() inside the while(1) loop.
When I monitor the SDA and SCL line (these lines have 4.7K pullups), the lines stays at all times HIGH!!. No I2C packets on my scope.
When I commented out the check_mode and hardcode the #use i2c statement at the beginning of my code, the hardware works instantly!
Question: Can we really change the #use I2C on the fly, by choice of a Mode Selection PIN? I would really appreciated if someone helps
Warmest Regards
lguancho
[/quote] |
|
![](templates/subSilver/images/spacer.gif) |
Mark
Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA
|
|
Posted: Wed Apr 06, 2005 8:19 am |
|
|
You can definitely switch between master and slave. Take a look at my code in the Code Library. I didn't use the #use, instead, I set it up manually. |
|
![](templates/subSilver/images/spacer.gif) |
lguancho
Joined: 08 Sep 2003 Posts: 5
|
Change I2C Master to I2C Slave on the Fly |
Posted: Thu Apr 07, 2005 8:03 pm |
|
|
Hi, Mark. Saw your code before. I am going to try it. Thanks
lguancho |
|
![](templates/subSilver/images/spacer.gif) |
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|