I am planning to use MSP430F6638 for SPI Communication between a single MSP430 Master and multiple MSP430 Slaves. I am using a 4×16 Multiplexer before each Slave for providing the Chip Select Signal. This allows for using 4 GPIO wires to address 16 Slaves.
I am curious about the following issues and would like to have suggestions about the possible solutions.
- The wire distance goes up to a maximum of 10m, will I face clock synchronization issues? What can I do to solve it?
- Should I use unidirectional line buffers on the CLK, SOMI, MOSI pins and Chip Select GPIO wires in order to be able to address 16 Slaves? As for the fan-out, the MSP430 datasheet says (as I understood) that fan-out must not increase 48mA on all pins combined and I am using some other peripherals simultaneously, so it’s difficult to calculate the remaining capability.
- Should I try going for a Daisy-Chain configuration? Does anybody have experience of writing software for Daisy Chain? Will it be of help using a Real Time Operating System or SYS/BIOS for writing the complex firmware required in case of Daisy Chain?
I would highly appreciate useful suggestions and comments. Thanks