add low power modes: med power turns off the camera preview, low power also dims the screen

Author: ladyada

adafruit_pycamera/__init__.py

@@ -72,6 +72,7 @@
 _NVM_EFFECT = const(2)
 _NVM_MODE = const(3)
 _NVM_TIMELAPSE_RATE = const(4)
+_NVM_TIMELAPSE_SUBMODE = const(5)
 
 
 class PyCameraBase:  # pylint: disable=too-many-instance-attributes,too-many-public-methods
@@ -186,6 +187,12 @@ class PyCameraBase:  # pylint: disable=too-many-instance-attributes,too-many-pub
         60 * 30,
         60 * 60
     )
+
+    timelapse_submodes = (
+        "HiPwr",
+        "MedPwr",
+        "LowPwr"
+    )
 
     modes = ("JPEG", "GIF", "GBOY", "STOP", "LAPS")
 
@@ -288,16 +295,18 @@ def make_camera_ui(self):
         self._botbar.append(self._mode_label)
 
         self._timelapsebar = displayio.Group(x=0, y=180)
+        self._timelapse_submode_label = label.Label(
+            terminalio.FONT, text="SubM", color=0xFFFFFF,x=160, y=10, scale=2
+        )
         self._timelapse_rate_label = label.Label(
             terminalio.FONT, text="Time", color=0xFFFFFF,x=90, y=10, scale=2
         )
-        self._timelapse_rate_label.background_color = None
         self._timelapsestatus_label = label.Label(
             terminalio.FONT, text="Status", color=0xFFFFFF, x=0, y=10, scale=2
         )
-        self._timelapsestatus_label.background_color = None
         self._timelapsebar.append(self._timelapse_rate_label)
         self._timelapsebar.append(self._timelapsestatus_label)
+        self._timelapsebar.append(self._timelapse_submode_label)
 
         self.splash.append(self._topbar)
         self.splash.append(self._botbar)
@@ -371,6 +380,7 @@ def init_camera(self, init_autofocus=True) -> None:
         self.resolution = microcontroller.nvm[_NVM_RESOLUTION]
         self.mode = microcontroller.nvm[_NVM_MODE]
         self.timelapse_rate = microcontroller.nvm[_NVM_TIMELAPSE_RATE]
+        self.timelapse_submode = microcontroller.nvm[_NVM_TIMELAPSE_SUBMODE]
 
         if init_autofocus:
             self.autofocus_init()
@@ -599,6 +609,18 @@ def timelapse_rate(self, setting):
         self.display.refresh()
 
 
+    @property
+    def timelapse_submode(self):
+        """Get or set the power mode for timelapsing"""
+        return self._timelapse_submode
+
+    @timelapse_submode.setter
+    def timelapse_submode(self, setting):
+        setting = (setting + len(self.timelapse_submodes)) % len(self.timelapse_submodes)
+        self._timelapse_submode = setting
+        self._timelapse_submode_label.text = self.timelapse_submodes[self._timelapse_submode]
+        microcontroller.nvm[_NVM_TIMELAPSE_SUBMODE] = setting
+
     def init_display(self):
         """Initialize the TFT display"""
         # construct displayio by hand

examples/camera/code.py

@@ -38,16 +38,26 @@
         )
         pycam.blit(last_frame)
     elif pycam.mode_text == "LAPS":
-        pycam.blit(pycam.continuous_capture())
-        pycam._timelapse_rate_label.text = pycam._timelapse_rate_label.text
         if timelapse_remaining is None:
             pycam._timelapsestatus_label.text = "STOP"
         else:
             timelapse_remaining = timelapse_timestamp - time.time()
             pycam._timelapsestatus_label.text = f"{timelapse_remaining}s /    "
+        pycam._timelapse_rate_label.text = pycam._timelapse_rate_label.text
+        pycam._timelapse_submode_label.text = pycam._timelapse_submode_label.text
+
+        # only in high power mode do we continuously preview
+        if (timelapse_remaining is None) or (pycam._timelapse_submode_label.text == "HiPwr"):
+            pycam.blit(pycam.continuous_capture())
+        if pycam._timelapse_submode_label.text == "LowPwr" and (timelapse_remaining is not None):
+            pycam.display.brightness = 0.05
+        else:
+            pycam.display.brightness = 1
         pycam.display.refresh()
 
         if timelapse_remaining is not None and timelapse_remaining <= 0:
+            # no matter what, show what was just on the camera
+            pycam.blit(pycam.continuous_capture())
             #pycam.tone(200, 0.1) # uncomment to add a beep when a photo is taken
             try:
                 pycam.display_message("Snap!", color=0x0000FF)
@@ -59,6 +69,8 @@
                 pycam.display_message("Error\nNo SD Card", color=0xFF0000)
                 time.sleep(0.5)
             pycam.live_preview_mode()
+            pycam.display.refresh()
+            pycam.blit(pycam.continuous_capture())
             timelapse_timestamp = time.time() + pycam.timelapse_rates[pycam.timelapse_rate] + 1
     else:
         pycam.blit(pycam.continuous_capture())
@@ -206,6 +218,9 @@
         # pycam.set_resolution(pycam.resolutions[new_res])
     if pycam.select.fell:
         print("SEL")
+        if pycam.mode_text == "LAPS":
+            pycam.timelapse_submode += 1
+            pycam.display.refresh()
     if pycam.ok.fell:
         print("OK")
         if pycam.mode_text == "LAPS":