Use RC as LF source for all board compatible

src/boards.c

@@ -61,7 +61,8 @@ uint16_t _pwm_blue_seq[PWM_CHANNEL_NUM] = { PWM_MAXCOUNT/2, 0, 0 , 0 };
 
 void board_init(void)
 {
-  NRF_CLOCK->LFCLKSRC = (uint32_t)((CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos) & CLOCK_LFCLKSRC_SRC_Msk);
+  // Use Internal OSC to compatible with all boards
+  NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_RC;
   NRF_CLOCK->TASKS_LFCLKSTART = 1UL;
 
   // stop WDT if started by application, when jumping from application using BLE DFU
@@ -106,6 +107,9 @@ void board_teardown(void)
   NRF_RTC1->INTENCLR    = RTC_INTENSET_COMPARE0_Msk;
   NRF_RTC1->TASKS_STOP  = 1;
   NRF_RTC1->TASKS_CLEAR = 1;
+
+  // Stop LF clock
+  NRF_CLOCK->TASKS_LFCLKSTOP = 1UL;
 }
 
 uint32_t tusb_hal_millis(void)
@@ -113,8 +117,6 @@ uint32_t tusb_hal_millis(void)
   return ( ( ((uint64_t)app_timer_cnt_get())*1000*(APP_TIMER_CONFIG_RTC_FREQUENCY+1)) / APP_TIMER_CLOCK_FREQ );
 }
 
-
-
 void led_pwm_init(uint32_t led_pin)
 {
   NRF_PWM_Type* pwm    = (led_pin == LED_RED) ? NRF_PWM0 : NRF_PWM1;

src/main.c

@@ -298,20 +298,13 @@ static uint32_t softdev_init(bool init_softdevice)
   // map vector table to bootloader address
   APP_ERROR_CHECK( sd_softdevice_vector_table_base_set(BOOTLOADER_REGION_START) );
 
-  // Enable Softdevice
+  // Enable Softdevice, Use Internal OSC to compatible with all boards
   nrf_clock_lf_cfg_t clock_cfg =
   {
-#if defined(NRF52840_XXAA) // TODO use xtal source for feather52832
-      .source       = NRF_CLOCK_LF_SRC_XTAL,
-      .rc_ctiv      = 0,
-      .rc_temp_ctiv = 0,
-      .accuracy     = NRF_CLOCK_LF_ACCURACY_20_PPM
-#else
       .source       = NRF_CLOCK_LF_SRC_RC,
       .rc_ctiv      = 16,
       .rc_temp_ctiv = 2,
-      .accuracy     = NRF_CLOCK_LF_ACCURACY_20_PPM
-#endif
+      .accuracy     = NRF_CLOCK_LF_ACCURACY_250_PPM
   };
 
   APP_ERROR_CHECK( sd_softdevice_enable(&clock_cfg, app_error_fault_handler) );