Add basic serial testing demo

demos/NRF51/RT-WVSHARE_BLE400/halconf.h

@@ -125,7 +125,7 @@
  * @brief   Enables the SERIAL subsystem.
  */
 #if !defined(HAL_USE_SERIAL) || defined(__DOXYGEN__)
-#define HAL_USE_SERIAL              FALSE
+#define HAL_USE_SERIAL              TRUE
 #endif
 
 /**

demos/NRF51/RT-WVSHARE_BLE400/main.c

@@ -32,6 +32,10 @@ int main(void) {
   halInit();
   chSysInit();
 
+  sdStart(&SD1, NULL);
+
+  chSequentialStreamWrite(&SD1, (const uint8_t *)"***\r\n", 5);
+  //chSequentialStreamWrite(&SD1, (const uint8_t *)"*", 1);
   while (1) {
     NRF_GPIO->OUTCLR = (uint32_t) 1 << 18;
     chThdSleepMilliseconds(500);

demos/NRF51/RT-WVSHARE_BLE400/mcuconf.h

@@ -20,5 +20,6 @@
 /*
  * HAL driver system settings.
  */
+#define NRF51_SERIAL_USE_UART0             TRUE
 
 #endif /* _MCUCONF_H_ */