Add PNVRAM support to avoid forgetting the time during a reboot.

1 files changed, 14 insertions, 2 deletions

diff --git a/wasp/drivers/nrf_rtc.py b/wasp/drivers/nrf_rtc.py
index 63a2a51..0ff2c1f 100644
--- a/wasp/drivers/nrf_rtc.py
+++ b/wasp/drivers/nrf_rtc.py
@@ -3,6 +3,7 @@
 
 """ Real Time Clock based on the nRF-family low power counter """
 
+import machine
 import time
 
 #class Stim(object):
@@ -20,8 +21,17 @@ class RTC(object):
 
     def __init__(self, counter):
         self.counter = counter
-        self._uptime = 0
-        self.set_localtime((2020, 3, 1, 3, 0, 0, 0, 0))
+
+	if machine.mem32[0x200039c0] == 0x1abe11ed and \
+	   machine.mem32[0x200039dc] == 0x10adab1e:
+            self.lastcount = self.counter.counter()
+	    self.offset = machine.mem32[0x200039c4]
+	    self._uptime = machine.mem32[0x200039c8] // 125
+	else:
+	    machine.mem32[0x200039c0] = 0x1abe11ed
+	    machine.mem32[0x200039dc] = 0x10adab1e
+	    self._uptime = 0
+	    self.set_localtime((2020, 3, 1, 3, 0, 0, 0, 0))
 
     def update(self):
         newcount = self.counter.counter()
@@ -34,6 +44,7 @@ class RTC(object):
         self.lastcount += split
         self.lastcount &= (1 << 24) - 1   
         self._uptime += split
+        machine.mem32[0x200039c8] = self._uptime * 125
 
         return True
 
@@ -52,6 +63,7 @@ class RTC(object):
 
         lt = time.mktime(t)
         self.offset = lt - (self._uptime >> 3)
+        machine.mem32[0x200039c4] = self.offset
 
     def get_localtime(self):
         self.update()