Badger OS: Add keepalive to fix #7.

Holding down a button, or pressing a button with the "right" timing would keep the Badger on, despite the 3v3 en pin being turned off.

This would result in abrupt power loss when the button is released, causing screen corruption.

badger_os/examples/badge.py

@@ -160,6 +160,10 @@ def draw_badge():
 draw_badge()
 
 while True:
+    # Sometimes a button press or hold will keep the system
+    # powered *through* HALT, so latch the power back on.
+    display.keepalive()
+
     if display.pressed(badger2040.BUTTON_A) or display.pressed(badger2040.BUTTON_B) or display.pressed(badger2040.BUTTON_C) or display.pressed(badger2040.BUTTON_UP) or display.pressed(badger2040.BUTTON_DOWN):
         badger_os.warning(display, "To change the text, connect Badger2040 to a PC, load up Thonny, and modify badge.txt")
         time.sleep(4)

badger_os/examples/ebook.py

@@ -189,6 +189,10 @@ def render_page():
     state["offsets"] = []
 
 while True:
+    # Sometimes a button press or hold will keep the system
+    # powered *through* HALT, so latch the power back on.
+    display.keepalive()
+
     # Was the next page button pressed?
     if display.pressed(badger2040.BUTTON_DOWN):
         state["current_page"] += 1

badger_os/examples/fonts.py

@@ -109,6 +109,10 @@ def draw_fonts():
 # ------------------------------
 
 while True:
+    # Sometimes a button press or hold will keep the system
+    # powered *through* HALT, so latch the power back on.
+    display.keepalive()
+
     if display.pressed(badger2040.BUTTON_UP):
         state["selected_font"] -= 1
         if state["selected_font"] < 0:

badger_os/examples/help.py

@@ -38,4 +38,5 @@
 # Call halt in a loop, on battery this switches off power.
 # On USB, the app will exit when A+C is pressed because the launcher picks that up.
 while True:
+    display.keepalive()
     display.halt()

badger_os/examples/image.py

@@ -90,6 +90,10 @@ def show_image(n):
 
 
 while True:
+    # Sometimes a button press or hold will keep the system
+    # powered *through* HALT, so latch the power back on.
+    display.keepalive()
+
     if display.pressed(badger2040.BUTTON_UP):
         if state["current_image"] > 0:
             state["current_image"] -= 1

badger_os/examples/info.py

@@ -41,4 +41,5 @@
 # Call halt in a loop, on battery this switches off power.
 # On USB, the app will exit when A+C is pressed because the launcher picks that up.
 while True:
+    display.keepalive()
     display.halt()

badger_os/examples/list.py

@@ -213,6 +213,10 @@ def draw_checkbox(x, y, size, background, foreground, thickness, tick, padding):
 # ------------------------------
 
 while True:
+    # Sometimes a button press or hold will keep the system
+    # powered *through* HALT, so latch the power back on.
+    display.keepalive()
+
     if len(list_items) > 0:
         if display.pressed(badger2040.BUTTON_A):
             if state["current_item"] > 0:

badger_os/examples/net_info.py

@@ -45,4 +45,5 @@
 # Call halt in a loop, on battery this switches off power.
 # On USB, the app will exit when A+C is pressed because the launcher picks that up.
 while True:
+    display.keepalive()
     display.halt()

badger_os/examples/news.py

@@ -176,8 +176,7 @@ def draw_page():
 
 draw_page()
 
-while 1:
-
+while True:
     changed = False
 
     if button_down.value():

badger_os/examples/qrgen.py

@@ -112,6 +112,10 @@ def draw_qr_file(n):
 changed = True
 
 while True:
+    # Sometimes a button press or hold will keep the system
+    # powered *through* HALT, so latch the power back on.
+    display.keepalive()
+
     if TOTAL_CODES > 1:
         if display.pressed(badger2040.BUTTON_UP):
             if state["current_qr"] > 0:

badger_os/examples/weather.py

@@ -103,4 +103,5 @@ def draw_page():
 # Call halt in a loop, on battery this switches off power.
 # On USB, the app will exit when A+C is pressed because the launcher picks that up.
 while True:
+    display.keepalive()
     display.halt()

badger_os/launcher.py

@@ -164,6 +164,10 @@ def button(pin):
 display.set_update_speed(badger2040.UPDATE_FAST)
 
 while True:
+    # Sometimes a button press or hold will keep the system
+    # powered *through* HALT, so latch the power back on.
+    display.keepalive()
+
     if display.pressed(badger2040.BUTTON_A):
         button(badger2040.BUTTON_A)
     if display.pressed(badger2040.BUTTON_B):

firmware/PIMORONI_BADGER2040/lib/badger2040.py

@@ -51,6 +51,9 @@
 
 WAKEUP_MASK = 0
 
+enable = machine.Pin(ENABLE_3V3, machine.Pin.OUT)
+enable.on()
+
 
 def is_wireless():
     return False
@@ -88,9 +91,12 @@ def system_speed(speed):
         pass
 
 
+def turn_on():
+    enable.on()
+
+
 def turn_off():
     time.sleep(0.05)
-    enable = machine.Pin(ENABLE_3V3, machine.Pin.OUT)
     enable.off()
     # Simulate an idle state on USB power by blocking
     # until a button event
@@ -150,6 +156,9 @@ def thickness(self, thickness):
     def halt(self):
         turn_off()
 
+    def keepalive(self):
+        turn_on()
+
     def pressed(self, button):
         return BUTTONS[button].value() == (0 if button == BUTTON_USER else 1) or pressed_to_wake_get_once(button)
 

firmware/PIMORONI_BADGER2040W/lib/badger2040.py

@@ -57,6 +57,9 @@
 i2c.writeto_mem(0x51, 0x00, b'\x00')  # ensure rtc is running (this should be default?)
 rtc.enable_timer_interrupt(False)
 
+enable = machine.Pin(ENABLE_3V3, machine.Pin.OUT)
+enable.on()
+
 
 def is_wireless():
     return True
@@ -92,9 +95,12 @@ def system_speed(speed):
         pass
 
 
+def turn_on():
+    enable.on()
+
+
 def turn_off():
     time.sleep(0.05)
-    enable = machine.Pin(ENABLE_3V3, machine.Pin.OUT)
     enable.off()
     # Simulate an idle state on USB power by blocking
     # until an RTC alarm or button event
@@ -187,6 +193,9 @@ def thickness(self, thickness):
     def halt(self):
         turn_off()
 
+    def keepalive(self):
+        turn_on()
+
     def pressed(self, button):
         return BUTTONS[button].value() == 1 or pressed_to_wake_get_once(button)