# TinyS3 Helper Library
# MIT license; Copyright (c) 2022 Seon Rozenblum - Unexpected Maker
#
# Project home:
#   https://tinys3.io

# Import required libraries
from micropython import const
from machine import Pin, ADC
import time

# TinyS3 Hardware Pin Assignments

# Sense Pins
VBUS_SENSE = const(33)
VBAT_SENSE = const(10)

# RGB LED Pins
RGB_DATA = const(18)
RGB_PWR = const(17)

# SPI
SPI_MOSI = const(35)
SPI_MISO = const(37)
SPI_CLK = const(36)

# I2C
I2C_SDA = const(8)
I2C_SCL = const(9)


# Helper functions
def set_pixel_power(state):
    """Enable or Disable power to the onboard NeoPixel to either show colour, or to reduce power for deep sleep."""
    Pin(RGB_PWR, Pin.OUT).value(state)


def get_battery_voltage():
    """
    Returns the current battery voltage. If no battery is connected, returns 4.2V which is the charge voltage
    This is an approximation only, but useful to detect if the charge state of the battery is getting low.
    """
    adc = ADC(Pin(VBAT_SENSE))  # Assign the ADC pin to read
    adc.atten(ADC.ATTN_2_5DB)  # Needs 2.5DB attenuation for max voltage of 1.116V w/batt of 4.2V
    measuredvbat = adc.read()
    measuredvbat /= 3657  # Divide by 3657 as we are using 2.5dB attenuation, which is max input of 1.25V = 4095 counts
    measuredvbat *= 4.2  # Multiply by 4.2V, our max charge voltage for a 1S LiPo
    return round(measuredvbat, 2)


def get_vbus_present():
    """Detect if VBUS (5V) power source is present"""
    return Pin(VBUS_SENSE, Pin.IN).value() == 1


# NeoPixel rainbow colour wheel
def rgb_color_wheel(wheel_pos):
    """Color wheel to allow for cycling through the rainbow of RGB colors."""
    wheel_pos = wheel_pos % 255

    if wheel_pos < 85:
        return 255 - wheel_pos * 3, 0, wheel_pos * 3
    elif wheel_pos < 170:
        wheel_pos -= 85
        return 0, wheel_pos * 3, 255 - wheel_pos * 3
    else:
        wheel_pos -= 170
        return wheel_pos * 3, 255 - wheel_pos * 3, 0
