December 11, 2019, 08:14:46 am

PIC-WEB and I2C

Started by samuele, October 17, 2012, 03:45:58 pm

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samuele

Hi,
I'm planning to use the PIC-WEB platform for one of my company projects.

The project requires to read some sensors (Sensirion SHT21/25) through I2C and provide a web interface to show the values read from the sensors.
I was thinking of using the SDA/SCL pin on the UEXT connector on the PIC-WEB to interface the PIC controller to the sensors.
Looking at the schematic I have seen that those pins are not connected to the MSSP port of the PIC, because the MSSP port of the PIC is used in SPI mode to connect the AT45DB011 flash chip, and the PIC18F67J60 has only one MSSP port.
So, my question is: how to get I2C on the SDA/SCL pins on the UEXT connector? Do I have to implement a bitbanged I2C? Or it could be possible to share the MSSP port pins on the UEXT connector with my I2C sensors?


Regards,
Samuele.

LubOlimex

Hello Samuele,

Yes. The SCL and SDA signals on the UEXT can be used as I2C without problems.

The older revisions of PIC-WEB had this problem but PIC18F67J60 has separate I2C and SPI interfaces.

Note that we have just updated the demo software to the latest stack version: https://www.olimex.com/Products/PIC/Development/PIC-WEB/resources/PIC_WEB_5_42.zip

Best regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex

cgcallebs

Why is it asking me for a password when I try to extract it?

cgcallebs

OK, you can tell I am a newbie. Once I read the agreement documents things became clear.