Interfacing 16F688 and MCP515

[Christopher4187]

I think the answer to this question is no but I wanted to be sure. There isn't any way to interface a 16F688 to a MCP2515, is there?

[HenrikOlsson]

It uses a SPI interface and the datasheet specifies no minimum SPI clock frequency so in theory SHIFTIN/SHIFTOUT should work. I have no idea if the bandwidth provided by SHIFTIN/SHIFTOUT will be enough for your application though.

Using a PIC with a MSSP-module would allow much (MUCH) higher SPI-clock frequency but the 16F688 doesn't have one so....

[Christopher4187]

I was hoping but......

My next option is to use an 18F4550. I know this can communicate with the MCP2515 but I may have another problem. I have an existing board that uses the USART on an 18F4550 to communicate with another PIC. The RX is on Portc.7. The SPI data out is also on Portc.7. Is there an easy workaround?

[HenrikOlsson]

No, no easy workaround as I see it.
On some PICs some of the peripheral can be switched to alternative pins but on the 4550 it seems that CCP2 is the only peripheral with that functionallity. So unless you can find a pin compatible PIC where the MSSP module is on another set of pin (guess it's not pin compatible then) or can be switched to a different set of pins I think you'll have to resort the SHIFTIN/SHIFTOUT - or a redesign....

/Henrik.