rtctime: expose set_rate to Lua

Author: nwf

app/modules/rtctime.c

@@ -144,6 +144,12 @@ static int rtctime_set (lua_State *L)
   return 0;
 }
 
+static int rtctime_set_rate (lua_State *L)
+{
+  rtc_time_set_rate(luaL_checkinteger(L, 1));
+  return 0;
+}
+
 // sec, usec = rtctime.get ()
 static int rtctime_get (lua_State *L)
 {
@@ -229,6 +235,7 @@ static int rtctime_epoch2cal (lua_State *L)
 // Module function map
 LROT_BEGIN(rtctime, NULL, 0)
   LROT_FUNCENTRY( set, rtctime_set )
+  LROT_FUNCENTRY( set_rate, rtctime_set_rate )
   LROT_FUNCENTRY( get, rtctime_get )
   LROT_FUNCENTRY( adjust_delta, rtctime_adjust_delta )
   LROT_FUNCENTRY( dsleep, rtctime_dsleep )

docs/modules/rtctime.md

@@ -158,6 +158,12 @@ rtctime.set(1436430589, 0)
 #### See also
 [`sntp.sync()`](sntp.md#sntpsync)
 
+## rtctime.set_rate()
+Adjust the RTC rate, as per [`rtctime.set()`](#rtctimeset), but without also setting the time.
+
+#### Syntax
+`rtctime.set_rate(rate)`
+
 ## rtctime.adjust_delta()
 
 This takes a time interval in 'system clock microseconds' based on the timestamps returned by `tmr.now` and returns

tools/luacheck_config.lua

@@ -540,7 +540,8 @@ stds.nodemcu_libs = {
         dsleep_aligned = empty,
         epoch2cal = empty,
         get = empty,
-        set = empty
+        set = empty,
+        set_rate = empty
       }
     },
     si7021 = {