wasp: pinetime: Basic RTC support

Currently this supports time only (no date) and it based on the
RTCounter class which is customized for nRF ports. At present
the nRF port doesn't have proper machine.rtc support so we have
implemented within wasp instead.

1 files changed, 58 insertions, 0 deletions

diff --git a/wasp/drivers/nrf_rtc.py b/wasp/drivers/nrf_rtc.py
new file mode 100644
index 0000000..c130a76
--- /dev/null
+++ b/wasp/drivers/nrf_rtc.py
@@ -0,0 +1,58 @@
+""" Real Time Clock based on the nRF-family low power counter """
+
+#class Stim(object):
+#    def __init__(self):
+#        self(0)
+#
+#    def __call__(self, v):
+#        self.c = v
+#    
+#    def counter(self):
+#        return self.c
+
+class RTC(object):
+    """Real Time Clock based on the nRF-family low power counter.
+
+    TODO: Maintain hh:mm:ss as an array so we can report time
+          without memory allocation.
+    """
+
+    def __init__(self, counter):
+        self.counter = counter
+        self.uptime = 0
+        self.set_time((12, 0, 0))
+
+    def update(self):
+        newcount = self.counter.counter()
+        split = newcount - self.lastcount
+        if split == 0:
+            return False
+        if split < 0:
+            split += (1 << 24)
+        elapsed = split // 8
+        self.lastcount += elapsed * 8 
+        self.lastcount &= (1 << 24) - 1   
+
+        self.uptime += elapsed
+
+        self.ss += elapsed
+        if self.ss >= 60:
+            self.mm += self.ss // 60
+            self.ss %= 60
+
+            if self.mm >= 60:
+                self.hh += self.mm // 60
+                self.mm %= 60
+                self.hh %= 24
+
+        return True
+
+    def set_time(self, t):
+        self.lastcount = self.counter.counter()
+        self.hh = t[0]
+        self.mm = t[1]
+        self.ss = t[2]
+
+    def get_time(self):
+        self.update()
+        return (self.hh, self.mm, self.ss)