wnorcott

OK here is an update I seem to have got the thing working with SPI on USCA0 of the MSP430G2553.  I just modified pins_energia.h and one file of the existing SPI library (usci_spi.cpp).   By working I mean I can hook up my SD card module to the A0 channel and with this code I am successfully logging to the SD card using the (unmodified) pfatfs library.
pins_energia.h I  added a  preprocessor flag #define SPI_USE_CHANNEL_A0 1 to remap the SPI pins constants // wnorcott 5/18/2015 // Uncomment the following ifdef to use USCI channel A0 instead // of B0 for SPI.  That means you can use hardware SPI and I2C  // simultaneously on the MSP430G2553 but you give up hardware  // serial capability.  The G2553 has two SPI channels A0 and B0. //#define SPI_USE_CHANNEL_A0 1 #define SPI_USE_CHANNEL_A0 1 #ifdef SPI_USE_CHANNEL_A0 static const uint8_t SS      = 7;   // P1.5  static const uint8_t SCK     = 6; // P1.4 UCA0CLK static const uint8_t MOSI    = 4; // P1.2 UCA0SIMO static const uint8_t MISO    = 3; // P1.1 UCA0SOMI #else static const uint8_t SS      = 8;  /* P2.0 */ static const uint8_t SCK     = 7;  /* P1.5 */ static const uint8_t MOSI    = 15; /* P1.7 */ static const uint8_t MISO    = 14; /* P1.6 */ #endif  changed SPI library module utility/usci_spi.cpp to test the new flag and variant the code to use channel A0: #ifdef SPI_USE_CHANNEL_A0 void spi_initialize(void) {   UCA0CTL1 = UCSWRST | UCSSEL_2;      // Put USCI in reset mode, source USCI clock from SMCLK   UCA0CTL0 = SPI_MODE_0 | UCMSB | UCSYNC | UCMST;  // Use SPI MODE 0 - CPOL=0 CPHA=0   pinMode_int(SCK, SPISCK_SET_MODE);   pinMode_int(MOSI, SPIMOSI_SET_MODE);   pinMode_int(MISO, SPIMISO_SET_MODE);   UCA0BR0 = SPI_CLOCK_DIV() & 0xFF;   // set initial speed to 4MHz   UCA0BR1 = (SPI_CLOCK_DIV() >> 8 ) & 0xFF;   UCA0CTL1 &= ~UCSWRST;    // release USCI for operation }  
... etc. in other words changed all the register references under the #ifdef to use USCI channel A0 hardware registers instead of channel B0.  The methods I had to monkey with under the #ifdef were: spi_initialize, spi_disable, spi_send,  spi_setdivisor, spi_set_bitorder,  and spi_set_datamode.
 
It would be nicer if  it were possible (and maybe it is) to add the #define SPI_USE_CHANNEL_A0 1 in my own sketch or at least pass it as a -D flag to the compiler when I build the sketch, instead of having to define it in pins_energia.h 
 
Thanks again for your help.

OK here is an update I seem to have got the thing working with SPI on USCA0 of the MSP430G2553.  I just modified pins_energia.h and one file of the existing SPI library (usci_spi.cpp).   By working I mean I can hook up my SD card module to the A0 channel and with this code I am successfully logging to the SD card using the (unmodified) pfatfs library.
pins_energia.h I  added a  preprocessor flag #define SPI_USE_CHANNEL_A0 1 to remap the SPI pins constants // wnorcott 5/18/2015 // Uncomment the following ifdef to use USCI channel A0 instead // of B0 for SPI.  That means you can use hardware SPI and I2C  // simultaneously on the MSP430G2553 but you give up hardware  // serial capability.  The G2553 has two SPI channels A0 and B0. //#define SPI_USE_CHANNEL_A0 1 #define SPI_USE_CHANNEL_A0 1 #ifdef SPI_USE_CHANNEL_A0 static const uint8_t SS      = 7;   // P1.5  static const uint8_t SCK     = 6; // P1.4 UCA0CLK static const uint8_t MOSI    = 4; // P1.2 UCA0SIMO static const uint8_t MISO    = 3; // P1.1 UCA0SOMI #else static const uint8_t SS      = 8;  /* P2.0 */ static const uint8_t SCK     = 7;  /* P1.5 */ static const uint8_t MOSI    = 15; /* P1.7 */ static const uint8_t MISO    = 14; /* P1.6 */ #endif  changed SPI library module utility/usci_spi.cpp to test the new flag and variant the code to use channel A0: #ifdef SPI_USE_CHANNEL_A0 void spi_initialize(void) {   UCA0CTL1 = UCSWRST | UCSSEL_2;      // Put USCI in reset mode, source USCI clock from SMCLK   UCA0CTL0 = SPI_MODE_0 | UCMSB | UCSYNC | UCMST;  // Use SPI MODE 0 - CPOL=0 CPHA=0   pinMode_int(SCK, SPISCK_SET_MODE);   pinMode_int(MOSI, SPIMOSI_SET_MODE);   pinMode_int(MISO, SPIMISO_SET_MODE);   UCA0BR0 = SPI_CLOCK_DIV() & 0xFF;   // set initial speed to 4MHz   UCA0BR1 = (SPI_CLOCK_DIV() >> 8 ) & 0xFF;   UCA0CTL1 &= ~UCSWRST;    // release USCI for operation }  
... etc. in other words changed all the register references under the #ifdef to use USCI channel A0 hardware registers instead of channel B0.  The methods I had to monkey with under the #ifdef were: spi_initialize, spi_disable, spi_send,  spi_setdivisor, spi_set_bitorder,  and spi_set_datamode.
 
It would be nicer if  it were possible (and maybe it is) to add the #define SPI_USE_CHANNEL_A0 1 in my own sketch or at least pass it as a -D flag to the compiler when I build the sketch, instead of having to define it in pins_energia.h 
 
Thanks again for your help.