Add Pimoroni Pico LiPo battery example

micropython/examples/pico_lipo_shim/battery.py

@@ -1,10 +1,15 @@
-# This example shows how to read the voltage from a lipo battery connected to a Raspberry Pi Pico via our Pico Lipo SHIM, and uses this reading to calculate how much charge is left in the battery.
+# This example shows how to read the voltage from a LiPo battery connected to a Raspberry Pi Pico via our Pico Lipo SHIM...
+# ...and uses this reading to calculate how much charge is left in the battery.
 # It then displays the info on the screen of Pico Display or Pico Explorer.
 # Remember to save this code as main.py on your Pico if you want it to run automatically!
 
 from machine import ADC, Pin
-import utime
-import picodisplay as display       # change "picodisplay" to "picoexplorer" if you're using a Pico Explorer
+import time
+
+# Uncomment one of these lines, depending on what display you have
+import picodisplay as display
+# import picodisplay2 as display
+# import picoexplorer as display
 
 # Set up and initialise display
 buf = bytearray(display.get_width() * display.get_height() * 2)
@@ -19,12 +24,13 @@ full_battery = 4.2                  # these are our reference voltages for a ful
 empty_battery = 2.8                 # the values could vary by battery size/manufacturer so you might need to adjust them
 
 while True:
+    # convert the raw ADC read into a voltage, and then a percentage
     voltage = vsys.read_u16() * conversion_factor
     percentage = 100 * ((voltage - empty_battery) / (full_battery - empty_battery))
     if percentage > 100:
         percentage = 100.00
 
-    # draws the battery
+    # draw the battery outline
     display.set_pen(0, 0, 0)
     display.clear()
     display.set_pen(190, 190, 190)
@@ -32,10 +38,12 @@ while True:
     display.rectangle(220, 40, 20, 55)
     display.set_pen(0, 0, 0)
     display.rectangle(3, 3, 214, 129)
+
+    # draw a green box for the battery level
     display.set_pen(0, 255, 0)
     display.rectangle(5, 5, round(210 / 100 * percentage), 125)
 
-    # adding text
+    # add text
     display.set_pen(255, 0, 0)
     if charging.value() == 1:         # if it's plugged into USB power...
         display.text("Charging!", 15, 55, 240, 4)
@@ -43,5 +51,10 @@ while True:
         display.text('{:.2f}'.format(voltage) + "v", 15, 10, 240, 5)
         display.text('{:.0f}%'.format(percentage), 15, 50, 240, 5)
 
+    # uncomment for low battery alarm (Pico Explorer only, you'll need to have GP0 and AUDIO connected with a jumper wire)
+    # display.set_audio_pin(0)
+    # if percentage < 5:               # if the battery is less than 5%
+    #     display.set_tone(262)        # then make an annoying noise
+
     display.update()
-    utime.sleep(1)
+    time.sleep(0.5)

micropython/examples/pimoroni_pico_lipo/battery.py

@@ -0,0 +1,62 @@
+# This example reads the voltage from a LiPo battery connected to Pimoroni Pico LiPo...
+# ...and uses this reading to calculate how much charge is left in the battery. 
+# It then displays the info on the screen of Pico Display or Pico Explorer.
+# With Pimoroni Pico LiPo, you can read the battery percentage while it's charging.
+# Save this code as main.py on your Pico if you want it to run automatically!
+
+from machine import ADC, Pin
+import time
+
+# Uncomment one of these lines, depending on what display you have
+import picodisplay as display
+# import picodisplay2 as display
+# import picoexplorer as display
+
+# Set up and initialise display
+buf = bytearray(display.get_width() * display.get_height() * 2)
+display.init(buf)
+display.set_backlight(0.8)          # comment out this line if you have a Pico Explorer, it doesn't have a controllable backlight
+
+vsys = ADC(29)                      # reads the system input voltage
+charging = Pin(24, Pin.IN)          # reading GP24 tells us whether or not USB power is connected
+conversion_factor = 3 * 3.3 / 65535
+
+full_battery = 4.2                  # reference voltages for a full/empty battery, in volts
+empty_battery = 2.8                 # the values could vary by battery size/manufacturer so you might need to adjust them
+
+while True:
+    # convert the raw ADC read into a voltage, and then a percentage
+    voltage = vsys.read_u16() * conversion_factor
+    percentage = 100 * ((voltage - empty_battery) / (full_battery - empty_battery))
+    if percentage > 100:
+        percentage = 100
+
+    # draw the battery outline
+    display.set_pen(0, 0, 0)
+    display.clear()
+    display.set_pen(190, 190, 190)
+    display.rectangle(0, 0, 220, 135)
+    display.rectangle(220, 40, 20, 55)
+    display.set_pen(0, 0, 0)
+    display.rectangle(3, 3, 214, 129)
+        
+    # draw a green box for the battery level
+    display.set_pen(0, 255, 0)
+    display.rectangle(5, 5, int((210 / 100) * percentage), 125)
+
+    # add text
+    display.set_pen(255, 0, 0)
+    if charging.value() == 1:         # if it's plugged into USB power...
+        display.text("Charging!", 15, 90, 240, 4)
+
+    display.text('{:.2f}'.format(voltage) + "v", 15, 10, 240, 5)
+    display.text('{:.0f}%'.format(percentage), 15, 50, 240, 5)
+
+    # uncomment for low battery alarm (Pico Explorer only, you'll need to have GP0 and AUDIO connected with a jumper wire)
+    # display.set_audio_pin(0)
+    # if percentage < 5:               # if the battery is less than 5%
+    #     display.set_tone(262)        # then make an annoying noise
+    
+    display.update()
+    time.sleep(0.5)
+