diff --git a/micropython/examples/pico_lipo_shim/battery.py b/micropython/examples/pico_lipo_shim/battery.py new file mode 100644 index 00000000..0d6d5b7f --- /dev/null +++ b/micropython/examples/pico_lipo_shim/battery.py @@ -0,0 +1,47 @@ +# 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 + +# 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 as 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 # these are our 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: + voltage = vsys.read_u16() * conversion_factor + percentage = 100 * ((voltage - empty_battery) / (full_battery - empty_battery)) + if percentage > 100: + percentage = 100.00 + + # draws the battery + 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) + display.set_pen(0, 255, 0) + display.rectangle(5, 5, round(210 / 100 * percentage), 125) + + # adding 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) + else: # if not, display the battery stats + display.text('{:.2f}'.format(voltage) + "v", 15, 10, 240, 5) + display.text('{:.0f}%'.format(percentage), 15, 50, 240, 5) + + display.update() + utime.sleep(1)