MC9S08JM32 & I2C? Hardware question...

[Betadine]

Hi all,

I´m trying to implement the 12bit DAC MCP4725A0T-E/CH on the MC9S08JM32 uC.

I´ve never worked with I2c and I don´t know how to connect it to the uC and what ports should I use.

I see that the uC have 2 SPI interfaces and one port for serial communications which I actually use for the USB trough an FT232 USB/serial converter.

Can I connect SPI interfaces to the I2C pins of the DAC? what chances I have?

Hope someone bring a little of light in this question, I have been reading something about SPI and I2C but I fear they are not the same at hardware level... so maybe is not possible?

Thanks in advance.

Cristian.

[iansmusical · Accepted solution]

Hi Cristian,

If you take a look at the reference manual/data sheet for the MC9S08JM32 you'll see a module named (S08IICV2). This is the I2C module which has dedicated pins and those that you'd use to connect to your MCP4725A0T. Connection wise SDA (data) goes to SDA, SCL (clock) goes to SCL and I think both need a 4k7? pull up to VCC.

I don't believe I2C and SPI are compatible simply because SPI requires 3 or 4 pins (separating the data transmit and data receive lines).

Hope this helps you.

Regards,

Ian

[Betadine]

Thanks!