LPC55S69 FLEXCOMM2 i2c bus

[ED8500]

Hi all,

Trying to get my LPC55S69 working as a i2c slave on Flexcomm2. The PCB I'm working on the Flexcomm2 is using GPIO1_26 (Sda) and GPIO1_27 (Scl). The config of the pins is ok, the config of the slave looks ok. Though my scope says the slave does not ACK the master and I get a 

"cdns-i2c ff030000.i2c: timeout waiting on completion"

when performing a (master uses bus 1 to communicate) "i2cdetect -y -r 1". I see the master sending out the correct address.

I have a second i2c bus (where NXP is master) on Flexcomm4 configured, there all works well.

Since flexcomm2 has a couple of pins to be used as i2c bus, is there any restriction on what pairs of pins used to form the i2c bus together? I found an example using PIO1_24 (Sda) and PIO1_25 (Scl).

Is there a way to use Flexcomm2 as an i2c bus on the eval LPC55S69-EVK board?

Thanks in advance!

[Alice_Yang]

Hello @ED8500 

1) "Since flexcomm2 has a couple of pins to be used as i2c bus, is there any restriction on what pairs of pins used to form the i2c bus together?"

->> No, you can refer to your requirements to choose.

2) "Is there a way to use Flexcomm2 as an i2c bus on the eval LPC55S69-EVK board?"

->> Yes, you can refer to I2C demo under SDK to config:

Recommend you first confirm demo can work well on you side, then change code based on it. 

Or you can use MCUXpresso config tool inside MCUXpresso IDE to config pins and also peripheral:

BR

Alice