topic I2C interface problem in LPCXpresso IDE

I2C interface problem

lpcware — Thu, 16 Jun 2016 01:37:05 GMT

Content originally posted in LPCWare by rhgirish108 on Fri Jun 21 02:09:55 MST 2013
Hello,

We are facing a very strange problem - and that is, the LPC1796 we are using is not generating I2C clock and data.

We programmed the relevant registers - but the problem is, when we probe the I2C SCLK and SDA line, we are not getting any waveform. We removed all the components/ICs like EEPROM with which it will communicate. We verified all relevant registers - like clock course, power control, I2C related etc.

But, atleast we should have observed the Start bit, the address sent out and the related clock. We tried it in three boards. No luck.

If anybody could help, that would be great

Regards
girish

Re: I2C interface problem

lpcware — Thu, 16 Jun 2016 01:37:06 GMT

Content originally posted in LPCWare by R2D2 on Fri Jun 21 02:30:14 MST 2013
I'm not familiar with this chip, but my LPC1769 requires pullups and a working program :confused:

Re: I2C interface problem

lpcware — Thu, 16 Jun 2016 01:37:07 GMT

Content originally posted in LPCWare by atomicdog on Mon Jun 24 23:36:02 MST 2013

Quote: rhgirish108
Hello,

We are facing a very strange problem - and that is, the LPC1796 we are using is not generating I2C clock and data.

We programmed the relevant registers - but the problem is, when we probe the I2C SCLK and SDA line, we are not getting any waveform. We removed all the components/ICs like EEPROM with which it will communicate. We verified all relevant registers - like clock course, power control, I2C related etc.

But, atleast we should have observed the Start bit, the address sent out and the related clock. We tried it in three boards. No luck.

If anybody could help, that would be great

Regards
girish

Without seeing your code it's really hard to guess. Do you have the required pull up resistors? Have you used a debugger to step through the code and see what happens?

Re: I2C interface problem

lpcware — Thu, 16 Jun 2016 01:37:07 GMT

Content originally posted in LPCWare by Rob65 on Wed Jun 26 23:21:56 MST 2013

Quote: R2D2
but my LPC1769 requires a working program :confused:

and I always though that these were smart devices :)

Now just show me the candy (or the code).
Did you also try one of the I2C examples that came with the LPCXpresso IDE ?
Did you provide the pull ups ? (the LPCXpresso board already contains the pull ups and an EEPROM)
Did you read the user manual and have you followed all instructions that are provided in there to get the I2C signals to the proper pins?

Rob