Voltage, amperage and power display using the ina219 i2c module w/ssd1306 128x64 screen

requires:

micropython version: >= v1.19.1-777-g129032941.uf2 due to the new bytearray.fromhex() function micropython ssd1306 library (only if using display)

other imports:

import time
from machine import I2C,Pin
import ssd1306
from micropython import const
from math import trunc

user configuration:

1. upload INA219.py to the lib location: /lib/INA219.py on the pico
2. configure the button PIN (default: GP16)
3. enter the mv_voltage bus resolution if different from the default (4 mV)
4. enter the max expected amperage (default 2.0)

code to configure in main.py if you want to display the results on an ssd1306 128x64 screen

button_pin = const(16)                #   <int> any GPIO pin on the rpico, the pin is kept low through a 100kΩ resistor and pulsed high to change display modes
...
mv_voltage_bus_resolution = const(4)  #   <int> change if different from 4 mV
max_expected_amperage = 2.0           #   <float> from 0.0 <--> 3.2 with the default 2.0