Photo-gate timer with CircuitPython

CircuitPython

CircuitPython is a flavor or port of MicroPython, by Adafruit Industries, to program any of hundreds of micro-controllers or single-board-computers with Python code. Changing the code on a board is simple: You copy a Python program file, and optionally libraries, to board that can be set to present itself to a computer as a USB drive. When you reset the board, it runs the file.

ESP32-S2 Reverse TFT Feather

The ESP32-S2 Reverse TFT Feather from Adafruit, https://www.adafruit.com/product/5345 , is an inexpensive development board with a WiFi capable

Code

import time
import board
import keypad
print("Photogate timer")

gates = (board.D1, board.D2)
#create empty list:
times = []
#track which gates have already been interrupted
passed = []
#interval is time in seconds to debounce button.
keys = keypad.Keys(gates, value_when_pressed=True, pull=True, interval=0.002)
while True:
    event=keys.events.get()
    if event:
        #print(event) #uncomment this to debug events
        #which gate was passed? event.key_number
        #if this is the first gate:
        if 0 == len(times):
            times.append(0.0)
            startTime = time.monotonic()
            #mark which gate has been passed
            passed.append(event.key_number)
            print(times)
        #else check if a gate not yet passed:
        elif 0 == passed.count(event.key_number):
            #Add the current time to the list
            times.append(time.monotonic() - startTime)
            passed.append(event.key_number)
            print(times)