Added a GPIO to power on/off for external I2C sensor(s) (with LEDs)

Dependencies:   UniGraphic mbed vt100

18-Jun-2018 外部センサの電源オン・オフ機能は下位互換の為に無効になっていました。 この版で再度有効にしました。

Revision:
0:846e2321c637
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/af_utils/mbedSPI.cpp	Fri Apr 13 04:19:23 2018 +0000
@@ -0,0 +1,74 @@
+#include "mbed.h"
+#include "vt100.h"
+#include "afSPI.h"
+#include "mbedSPI.h"
+
+#if defined (TARGET_KL25Z) || defined (TARGET_TEENSY3_1)
+ #ifndef SPI0_C1
+  #define SPI0_C1 (*(uint8_t *)0x40076000)
+ #endif
+#endif
+/*
+class mbedSPI : public afSPI {
+public:
+    mbedSPI(PinName mosi, PinName miso, PinName sckl, PinName cs) ;
+    virtual void begin() ;
+    virtual void beginSPI() ;
+    virtual void endSPI() ;
+    virtual void transfer(char *bytes,int len) ;
+private:
+    SPI         _spi ;
+    DigitalOut  _cs ;
+} ;
+*/
+
+mbedSPI::mbedSPI(PinName mosi, PinName miso, PinName sckl, PinName cs) :
+    _spi(mosi, miso, sckl), _cs(cs, 1)
+{
+    _spi.format(8, 0) ;
+    _spi.frequency(1000000) ; /* 1MHz */
+
+#if defined (TARGET_KL25Z) || defined (TARGET_TEENSY3_1)
+    #ifndef SPI0_C1
+        #define SPI0_C1 (*(uint8_t *)0x40076000)
+    #endif
+//    SPI0_C1 |= 0x01 ; /* LSB First */
+//    SPI0_C1 &= 0xFE ; /* MSB First */
+#endif
+
+}
+
+void mbedSPI::begin(void)
+{
+}
+
+void mbedSPI::beginSPI()
+{
+//    printf("+") ; fflush(stdout) ;
+    _cs = 0 ;
+    SPI0_C1 |= 0x01 ; /* LSB First */
+    wait_us(1) ;
+}
+
+void mbedSPI::endSPI()
+{
+    _cs = 1 ;
+    SPI0_C1 &= 0xFE ; /* MSB First */
+    wait_us(1) ;
+//    printf("-") ; fflush(stdout) ;
+}
+
+/**
+ * on 17-Jan-2018 disable/enable irq added
+ * before and after of each _spi.writes
+ */
+void mbedSPI::transfer(char *bytes, int len)
+{
+    int i ;
+    for (i = 0 ; i < len ; i++ ) {
+        __disable_irq() ; // Disable Interrupts
+        bytes[i] = _spi.write(bytes[i]) ;
+        __enable_irq() ; // Enable Interrupts
+    }
+}
+