This is an updated version of an earlier post. The earlier post did not use classes. Here is the link to that post in case a slightly less functional non-class version is helpful.

This post is a walkthrough for having neopixels (individually addressable LEDs) flash in firefly patterns. The script uses circuitpython and uses three flash patterns from a National Park Service website. It should be very easy to add additional patterns as you see fit. The full script can be found here.

The current version of the script can easily accommodate an arbitrary number of lights, randomly assigning a firefly type to each one.

Here’s the full code:

#https://www.nps.gov/grsm/learn/nature/firefly-flash-patterns.htm

import board
import digitalio
import time
import neopixel
import random



#variables to hold the color that the LED will blink
neo_r = 255
neo_g = 255
neo_b = 0

# variable to hold the number of neopixels
number_of_lights = 10

#create the neopixel. auto_write=True avoids having to push changes (at the cost of speed, which probably doesn't matter here)
pixels = neopixel.NeoPixel(board.NEOPIXEL, number_of_lights, brightness = 0.1, auto_write=False)

# sets up the bug holder list, which holds all of the bug objects

bug_holder = []


# sets up the bug class

class Bug:
    def __init__(self, type, reset_time_input, light_number):
        self.type = type
        self.reset_time_input = reset_time_input
        self.light_number = light_number


#functions to turn light on and off
def on(light_num):
    pixels[light_num] = (neo_r, neo_g, neo_b)
    pixels.show()
def off(light_num):
    pixels[light_num] = (0, 0, 0)
    pixels.show()


#functions for the types of fireflies
def brimleyi(reset_time_input, light_number):
    #calculates how much time has passed since the new zero
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    # on flash
    if 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 15 <= time_from_zero <= 15.5:
        on(light_number)

    # reset (includes 10 seconds after second flash - 5 on the back end and 5 on the front end)
    elif time_from_zero > 20:
        off(light_number)
        reset_time = time.monotonic() + random.uniform(-3, 3)

    # all of the off times
    else:
        off(light_number)

    return reset_time

def macdermotti (reset_time_input, light_number):
    #calculates how much time has passed since the new zero
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    # on flash
    if 3 <= time_from_zero <= 3.5:
        on(light_number)
    elif 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 10 <= time_from_zero <= 10.5:
        on(light_number)
    elif 12 <= time_from_zero <= 12.5:
        on(light_number)

    elif time_from_zero > 14.5:
        off(light_number)
        reset_time = time.monotonic() + random.uniform(-3, 3)

    else:
        off(light_number)

    return reset_time

def carolinus(reset_time_input, light_number):
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    if 0 <= time_from_zero <= 0.5:
        on(light_number)
    elif 1 <= time_from_zero <= 1.5:
        on(light_number)
    elif 2 <= time_from_zero <= 2.5:
        on(light_number)
    elif 3 <= time_from_zero <= 3.5:
        on(light_number)
    elif 4 <= time_from_zero <= 4.5:
        on(light_number)
    elif 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 6 <= time_from_zero <= 6.5:
        on(light_number)

    elif time_from_zero >= 15:
        off(light_number)
        reset_time = time.monotonic()

    else:
        off(light_number)

    return reset_time


#create all of the light objects by appending a new light object to the list for each neopixel
#the first argument (random.randint(1, 3)) is used to assign a random number which corresponds to one of the ff functions
#if you start adding lots of those it might be worth using a universal variable

for i in range (0, number_of_lights):
    bug_holder.append(Bug(random.randint(1, 3), time.monotonic(), i))


while True:

    #iterates through all of the light objects in the bug_holder list
    #use the series of if statements to match the randomly assigned number to the types of fireflies

    for i in range (0, number_of_lights):
        if bug_holder[i].type == 1:
            bug_holder[i].reset_time_input = brimleyi(bug_holder[i].reset_time_input, i)
        elif bug_holder[i].type == 2:
            bug_holder[i].reset_time_input = macdermotti(bug_holder[i].reset_time_input, i)
        elif bug_holder[i].type == 3:
            bug_holder[i].reset_time_input = carolinus(bug_holder[i].reset_time_input, i)
        #this is just a catchall if there is some sort of error
        else:
            bug_holder[i].reset_time_input = brimleyi(bug_holder[i].reset_time_input, i)
            print("number error")


    #briefly pauses the loop to avoid crashing the USB bus. Also makes it easier to see what is happening.
    time.sleep(0.25)

At a high level, it creates a Bug class for each light, three functions (one for each type of firefly flash pattern) and then assigns that pattern to a light. The patterns are based on timing, so it uses the monotonic() function to keep track of time. There is not a real clock on microcontrollers, so monotonic() just counts up from the moment the board turns on.

#https://www.nps.gov/grsm/learn/nature/firefly-flash-patterns.htm

import board
import digitalio
import time
import neopixel
import random

The first part of the code imports the libraries used by the script.

#variables to hold the color that the LED will blink
neo_r = 255
neo_g = 255
neo_b = 0

The next part holds the color for the LED. The current color is yellow, although you could make it whatever you want. This script uses the same color for all of the lights, regardless of their pattern.

# variable to hold the number of neopixels
number_of_lights = 10

This variable holds the number of lights you are using. This makes it easy to change the number of lights you are controlling.

#create the neopixel. auto_write=True avoids having to push changes (at the cost of speed, which probably doesn't matter here)
pixels = neopixel.NeoPixel(board.NEOPIXEL, number_of_lights, brightness = 0.2, auto_write=False)

This line initializes the neopixels. I developed this on an Adafruit circuit playground board, so you may need to change this line depending on your setup. The other thing to point out here is that the brightness variable is set to 0.2. Neopixels are bright, so I toned things down during development. You might want to make them brighter for your final installation.

# sets up the bug holder list, which holds all of the bug objects

bug_holder = []

This creates the list to hold each individual instance of the bug light object. Holding them in a list makes it easy to address them as necessary.

# sets up the bug class

class Bug:
    def __init__(self, type, reset_time_input, light_number):
        self.type = type
        self.reset_time_input = reset_time_input
        self.light_number = light_number

This creates the Bug class. Each individual neopixel is an instantiation of a ‘Bug’. It has a type, which corresponds to the flash pattern it uses, a reset_time_input to keep track of time, and a light_number to assign it to a specific light. It is possible that the light_number is redundant because it also corresponds to its order in the list, but I’m still in baby step territory so I didn’t want to push it.

def on(light_num):
    pixels[light_num] = (neo_r, neo_g, neo_b)
    pixels.show()
def off(light_num):
    pixels[light_num] = (0, 0, 0)
    pixels.show()

These two little functions define the neopixel being on and being off. Each pattern function needs to turn lights on and off, so it was easier to define that behavior once and reuse it as a function.

def brimleyi(reset_time_input, light_number):
    #calculates how much time has passed since the new zero
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    # on flash
    if 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 15 <= time_from_zero <= 15.5:
        on(light_number)

    # reset (includes 10 seconds after second flash - 5 on the back end and 5 on the front end)
    elif time_from_zero > 20:
        off(light_number)
        reset_time = time.monotonic() + random.uniform(-3, 3)

    # all of the off times
    else:
        off(light_number)

    return reset_time

This is the first blinking function. It takes two arguments. The reset_time_input is the counter start time. The light_number is which neopixel it is controlling.

Without a real clock, all of the flash functions are controlled by a counter. You can think of the counter starting at 0 for the first loop (it doesn’t actually start a 0 the first time, but ignore that for a minute).

time_from_zero = time.monotonic() - reset_time_input figures out how long it has been since the start of the counter. In the example first loop, the reset_time_input would be 0. If it has been 2 seconds since the counter started counting, the time_from_zero would equal 2.

That value is then compared to a bunch of if statements that determine if the light is on or off. In this first function, the light goes on if the time_from_zero is between 5 and 5.5 seconds, and between 15 and 15.5 seconds. Because the default state of things is that the light is off, we only need if triggers for when the light needs to be on.

Once the time_from_zero exceeds 20 seconds, the counter resets. That reset is based on the current time (time.monotonic()) with a bit of random variation (random.uniform(-3, 3)) so that the different lights are not all in sync (the carolinus() function does not include this random variation because the carolinus bugs flash in unison).

As soon as the cycle is complete, it returns a new reset_time. Remember that there is only one counter on the board, and it just keeps counting up. The first time through the cycle, reset_time_input might be 0. The second time through, the cycle ‘starts’ closer to 20. Similarly, instead of being 2 the first time around, the time.monotonic() will be 22 the second time around. The time_from_zero function normalizes all of this, because 2-0, 22-20, and 82-80 are all the same value. That allows the function to keep working over time.

The macdermotti() and carolinus() functions work the same way. If you want to make a new function for a new pattern, just duplicate it, rename it, and change the if statements.

#create all of the light objects by appending a new light object to the list for each neopixel
#the first argument (random.randint(1, 3)) is used to assign a random number which corresponds to one of the ff functions
#if you start adding lots of those it might be worth using a universal variable

for i in range (0, number_of_lights):
    bug_holder.append(Bug(random.randint(1, 3), time.monotonic(), i))

Having done all of the setup work, this is where things start to actually happen. This loop creates as many Bug instances as necessary to match the number of lights you want to control. The first argument random.randint(1, 3) assigns an integer that corresponds to one of the three blink functions. The second argument time.monotonic() is the start time based on the board’s counter. The last argument i assigns the instance to a specific light.

while True:

    #iterates through all of the light objects in the bug_holder list
    #use the series of if statements to match the randomly assigned number to the types of fireflies

    for i in range (0, number_of_lights):
        if bug_holder[i].type == 1:
            bug_holder[i].reset_time_input = brimleyi(bug_holder[i].reset_time_input, i)
        elif bug_holder[i].type == 2:
            bug_holder[i].reset_time_input = macdermotti(bug_holder[i].reset_time_input, i)
        elif bug_holder[i].type == 3:
            bug_holder[i].reset_time_input = carolinus(bug_holder[i].reset_time_input, i)
        #this is just a catchall if there is some sort of error
        else:
            bug_holder[i].reset_time_input = brimleyi(bug_holder[i].reset_time_input, i)
            print("number error")

This is the loop that constantly checks each light to see if it should be on or off based on the pattern assigned to it. As it loops through each of the lights:

  for i in range (0, number_of_lights):

it looks to see which type of light it is. It then uses the type to decide which pattern function to use. The end of each function returns their ‘new’ reset time even if their state did not change, so these sections end by updating the reset time.

Now that all of the functions work, this while loop will just keep running them forever.

#briefly pauses the loop to avoid crashing the USB bus. Also makes it easier to see what is happening.
    time.sleep(0.25)

This last line just rests for 0.25 seconds. Before I added it, the looping was flooding the USB bus and creating all sorts of problems. Briefly pausing everything just makes it easier to work with.

header image: Case (Inrō) with Design of Fireflies in Flight and Climbing on Stone Baskets and Reeds at the Shore

Today I filed a petition to expand the scope of the current (expiring) rule about unlocking 3D printers. The full petition is here. That follows a petition I filed in July to simply renew the current rule. That renewal petition is here. The petitions are short because the substantive discussion will be reserved for the hearing phase.

In June I wrote that the purpose of this process was to continue to clarify that 3D printer manufacturers cannot use copyright law to prevent people from using third party 3D printer material.

If no one objects to the renewal request, the Copyright Office will recommend that it be renewed without any additional process. If someone does object, they Copyright Office will hold hearings to consider the renewal. Regardless of the status of the renewal petition, the Copyright Office will hold a hearing about the expansion. We should find out reasonably soon if the hearings will include the renewal as well as the expansion, a well as when the hearings will be.

As I explained in my earlier post, the purpose of the expansion is to renew qualifying language from the current rule that brings additional confusion instead of clarity. I hope that no one objects to the expansion, but you never know.

Finally, thank you to everyone who submitted information about printers that:

requires you to purchase printing material (filament, powder, resin, etc.) from the printer manufacturer (or approved vendor)

AND

uses something besides a microchip to verify the source of the material.

These examples will be incorporated into the more substantive filing that is made as part of the hearing phase. If you have an example that fits this criteria and have not already sent it in, it is not too late! Please email me at hello@michaelweinberg.org or dm me on twitter @mweinberg2D. Feel free to send me this information anonymously if you prefer.

Last month the Metropolitan Museum of Art announced a series of partnerships that brought famous works in the Met’s collections to limited edition items from a series of brand partners. This announcement may end up being one of the most important developments for museum open access this year (and it’s been a busy year for museum open access).

In 2017 the Met made all images of public domain works in its collection available under a Creative Commons Zero (CCO) license. As commenters quickly pointed out, this open access program means that none of the just-announced brand partners needed to partner with the Met in order to incorporate works from the Met’s collection into the products.

And yet, these brands still decided to enter into a formal partnership with the Met to put the Met’s collection on their products. In doing so, they validated an important path for open access success. These new partnerships show how the power of an institution’s brand can help it monetize an open access program.

A Recurring Open Access Question - Can it Make Money?

Many cultural institutions have revenue-related internal discussions when they are considering creating open access programs. While many people argue that open access should be a core part of the mission of cultural institutions regardless of its impact on revenue, it is clear that revenue implications are part of many institution’s evaluation of open access.

Oftentimes, the discussion is tied to concerns that open access will eliminate revenue that the institution currently receives from licensing its collection. Within this context, it is first important to remember that the role of revenue from image licensing is a disputed one. A Mellon Foundation study from 2004 suggests that many institutions actually lose money on licensing because the costs of operating the program exceed any revenues associated with it. Also, the idea of licensing works already in the public domain strikes many as problematic, if not illegitimate.

Nonetheless, it can be helpful for open access proponents to have a way to address revenue concerns related to open access programs. While there are a number of ways to approach this question, many of the easiest to conceptualize options rely on leveraging the institution’s brand. Unlike the works, which are made publicly available under an open access program, the institution maintains control over its brand even if the works they control are available to everyone.

As a result, while anyone can put The Unicorn Rests in the Garden on a tote bag, only BAGGU can tout their bags as being part of “A limited collection created in collaboration with the Metropolitan Museum of Art”. In many cases, that formal association with the institution’s brand is valuable.

How Will This Apply to Others?

Admittedly, not all cultural institutions have brands that are as prominent as the Met. However, there is likely to be a correlation between the amount of revenue an institution historically saw from image licensing and the value of that institution’s brand. That is what makes the brand licensing path an interesting one in the context of open access, and why these partnerships are especially interesting.

This program means that partnering with the Met because of its brand - as opposed to obtaining access to its collection - is interesting to a wide range of companies. Will it be successful enough to sustain their attention? Will success translate to institutions with brands that are not as strong as the Met’s? It is too early to say. Either way, it is encouraging to see the Met continue to show leadership with open access.

Feature image: A Goldsmith in His Shop by Petrus Christus

Update 10/11/20: I did figure out how to use classes to automatically scale this to n lights! Updated post is here.

This post is a walkthrough for having neopixels (individually addressable LEDs) flash in firefly patterns. The script uses circuitpython and uses three flash patterns from a National Park Service website. It should be very easy to add additional patterns as you see fit. The full script can be found here.

One quick note before getting started. The current version of the script has 90% of the functionality I want it to have. I have a strong suspicion that the last 10% will require a full rewrite and more complex code. I’m putting up this post with simple code for anyone who wants to avoid the more complex version (if it ever ends up existing).

Here’s the full code:

#https://www.nps.gov/grsm/learn/nature/firefly-flash-patterns.htm

import board
import digitalio
import time
import neopixel
import random



#variables to hold the color that the LED will blink
neo_r = 255
neo_g = 255
neo_b = 0

# variable to hold the number of neopixels
number_of_lights = 7

#create the neopixel. auto_write=True avoids having to push changes (at the cost of speed, which probably doesn't matter here)
pixels = neopixel.NeoPixel(board.NEOPIXEL, number_of_lights, brightness = 0.2, auto_write=False)

# automatically spins up the seed reset times for each light
reset_time_dict = {}

# sets the seeds to zero
for i in range(0, number_of_lights):
    var_name = 'resetTime' + str(i)
    reset_time_dict[var_name] = time.monotonic()


print(reset_time_dict)

def on(light_num):
    pixels[light_num] = (neo_r, neo_g, neo_b)
    pixels.show()
def off(light_num):
    pixels[light_num] = (0, 0, 0)
    pixels.show()

def brimleyi(reset_time_input, light_number):
    #calculates how much time has passed since the new zero
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    # on flash
    if 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 15 <= time_from_zero <= 15.5:
        on(light_number)

    # reset (includes 10 seconds after second flash - 5 on the back end and 5 on the front end)
    elif time_from_zero > 20:
        off(light_number)
        reset_time = time.monotonic() + random.uniform(-3, 3)

    # all of the off times
    else:
        off(light_number)

    return reset_time

def macdermotti (reset_time_input, light_number):
    #calculates how much time has passed since the new zero
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    # on flash
    if 3 <= time_from_zero <= 3.5:
        on(light_number)
    elif 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 10 <= time_from_zero <= 10.5:
        on(light_number)
    elif 12 <= time_from_zero <= 12.5:
        on(light_number)

    elif time_from_zero > 14.5:
        off(light_number)
        reset_time = time.monotonic() + random.uniform(-3, 3)

    else:
        off(light_number)

    return reset_time

def carolinus(reset_time_input, light_number):
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    if 0 <= time_from_zero <= 0.5:
        on(light_number)
    elif 1 <= time_from_zero <= 1.5:
        on(light_number)
    elif 2 <= time_from_zero <= 2.5:
        on(light_number)
    elif 3 <= time_from_zero <= 3.5:
        on(light_number)
    elif 4 <= time_from_zero <= 4.5:
        on(light_number)
    elif 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 6 <= time_from_zero <= 6.5:
        on(light_number)

    elif time_from_zero >= 15:
        off(light_number)
        reset_time = time.monotonic()

    else:
        off(light_number)

    return reset_time


while True:

    reset_time_dict["resetTime2"] = brimleyi(reset_time_dict["resetTime2"], 2)
    reset_time_dict["resetTime3"] = brimleyi(reset_time_dict["resetTime3"], 3)
    reset_time_dict["resetTime4"] = macdermotti(reset_time_dict["resetTime4"], 4)
    reset_time_dict["resetTime5"] = carolinus(reset_time_dict["resetTime5"], 5)
    reset_time_dict["resetTime6"] = carolinus(reset_time_dict["resetTime6"], 6)





    #briefly pauses the loop to avoid crashing the USB bus. Also makes it easier to see what is happening.
    time.sleep(0.25)

At a high level, it creates three functions (one for each type of firefly flash pattern) and then assigns that pattern to a light. The patterns are based on timing, so it uses the monotonic() function to keep track of time. There is not a real clock on microcontrollers, so monotonic() just counts up from the moment the board turns on.

#https://www.nps.gov/grsm/learn/nature/firefly-flash-patterns.htm

import board
import digitalio
import time
import neopixel
import random

The first part of the code imports the libraries used by the script.

#variables to hold the color that the LED will blink
neo_r = 255
neo_g = 255
neo_b = 0

The next part holds the color for the LED. The current color is yellow, although you could make it whatever you want. This script uses the same color for all of the lights, regardless of their pattern.

# variable to hold the number of neopixels
number_of_lights = 7

This variable holds the number of lights you are using. It is moderately useful to have this as a variable now, and likely very useful when the script is fully functional and can automatically populate n lights.

#create the neopixel. auto_write=True avoids having to push changes (at the cost of speed, which probably doesn't matter here)
pixels = neopixel.NeoPixel(board.NEOPIXEL, number_of_lights, brightness = 0.2, auto_write=False)

This line initializes the neopixels. I developed this on an Adafruit circuit playground board, so you may need to change this line depending on your setup. The other thing to point out here is that the brightness variable is set to 0.2. Neopixels are bright, so I toned things down during development. You might want to make them brighter for your final installation.

# automatically spins up the seed reset times for each light
reset_time_dict = {}

This creates a dictionary to hold the reset times for each light. Each light resets its timer at the end of a cycle, so you need a variable to hold the reset time for each individual light.

# sets the seeds to zero
for i in range(0, number_of_lights):
    var_name = 'resetTime' + str(i)
    reset_time_dict[var_name] = time.monotonic()

This automatically sets the reset time for each light, by iterating based on the number_of_lights variable from above.

print(reset_time_dict)

This print line was just for troubleshooting. I should probably just delete it.

def on(light_num):
    pixels[light_num] = (neo_r, neo_g, neo_b)
    pixels.show()
def off(light_num):
    pixels[light_num] = (0, 0, 0)
    pixels.show()

These two little functions define the neopixel being on and being off. Each pattern function needs to turn lights on and off, so it was easier to define that behavior once and reuse it as a function.

def brimleyi(reset_time_input, light_number):
    #calculates how much time has passed since the new zero
    time_from_zero = time.monotonic() - reset_time_input
    # creates the carry over reset_time variable so that it can be returned even if it is not updated in the last if statement
    reset_time = reset_time_input

    # on flash
    if 5 <= time_from_zero <= 5.5:
        on(light_number)
    elif 15 <= time_from_zero <= 15.5:
        on(light_number)

    # reset (includes 10 seconds after second flash - 5 on the back end and 5 on the front end)
    elif time_from_zero > 20:
        off(light_number)
        reset_time = time.monotonic() + random.uniform(-3, 3)

    # all of the off times
    else:
        off(light_number)

    return reset_time

This is the first blinking function. It takes two arguments. The reset_time_input is the counter start time. The light_number is which neopixel it is controlling.

Without a real clock, all of the flash functions are controlled by a counter. You can think of the counter starting at 0 for the first loop (it doesn’t actually start a 0 the first time, but ignore that for a minute).

time_from_zero = time.monotonic() - reset_time_input figures out how long it has been since the start of the counter. In the example first loop, the reset_time_input would be 0. If it has been 2 seconds since the counter started counting, the time_from_zero would equal 2.

That value is then compared to a bunch of if statements that determine if the light is on or off. In this first function, the light goes on if the time_from_zero is between 5 and 5.5 seconds, and between 15 and 15.5 seconds. Because the default state of things is that the light is off, we only need if triggers for when the light needs to be on.

Once the time_from_zero exceeds 20 seconds, the counter resets. That reset is based on the current time (time.monotonic()) with a bit of random variation (random.uniform(-3, 3)) so that the different lights are not all in sync (the carolinus() function does not include this random variation because the carolinus bugs flash in unison).

As soon as the cycle is complete, it returns a new reset_time. Remember that there is only one counter on the board, and it just keeps counting up. The first time through the cycle, reset_time_input might be 0. The second time through, the cycle ‘starts’ closer to 20. Similarly, instead of being 2 the first time around, the time.monotonic() will be 22 the second time around. The time_from_zero function normalizes all of this, because 2-0, 22-20, and 82-80 are all the same value. That allows the function to keep working over time.

The macdermotti() and carolinus() functions work the same way. If you want to make a new function for a new pattern, just duplicate it, rename it, and change the if statements.

while True:

    reset_time_dict["resetTime2"] = brimleyi(reset_time_dict["resetTime2"], 2)
    reset_time_dict["resetTime3"] = brimleyi(reset_time_dict["resetTime3"], 3)
    reset_time_dict["resetTime4"] = macdermotti(reset_time_dict["resetTime4"], 4)
    reset_time_dict["resetTime5"] = carolinus(reset_time_dict["resetTime5"], 5)
    reset_time_dict["resetTime6"] = carolinus(reset_time_dict["resetTime6"], 6)

Now that all of the functions work, this while loop will just keep running them forever.

reset_time_dict["resetTime2"] starts with the reset time for light #2 that we automatically generated at the top of the script. brimleyi(reset_time_dict["resetTime2"], 2) calls the brimleyi() function, using that reset time. Because the end of the functions all return their ‘new’ reset time (even if it was not updated that cycle), the reset time in the dictionary will always be the one you want to work with.

#briefly pauses the loop to avoid crashing the USB bus. Also makes it easier to see what is happening.
    time.sleep(0.25)

This last line just rests for 0.25 seconds. Before I added it, the looping was flooding the USB bus and creating all sorts of problems. Briefly pausing everything just makes it easier to work with.

At the top of this post I mentioned that the script did 90% of what I want it to do. The remaining 10% has to do with everything in the while loop.

You might have noticed that the reset times are automatically generated for each light at the start of the loop. However, you need to manually create an entry for every light in the while loop.

Ideally, this script would automatically create the entries for the lights in the while loop and randomly assign them a flash pattern. Unfortunately, I think doing so will probably require turning the pattern functions into classes. Or at least that’s what the Coding Train’s Nature of Code series has me thinking about these days.

Classes or no classes, I still haven’t figure out how to fully automate things yet. Once I do, I’ll post some updated code. Until then, hopefully this is useful to someone else.

header image: Case (Inrō) with Design of Fireflies in Flight and Climbing on Stone Baskets and Reeds at the Shore

This post originally appeared on the Engelberg Center blog.

We anticipate being able to support Glam3D.org, our newly launched site focusing on creating Open Access 3D cultural resources, well into the future. Nonetheless, we also recognize that technology evolves, priorities change, and that there may be a day where the site is no longer viable. As a result, we have taken steps to make it easier to preserve the site if and when it is no longer active.

In many situations, planning to preserve digital resources can be an elaborate task. Sites built on complex content management systems (CMS) relying on proprietary software can simply disappear. Even the most ubiquitous technologies can fade over time (see, for example, attempts to preserve flash-based web media now that flash is no longer actively supported). Although organizations like the Internet Archive work hard to preserve some digital resources, even their powers have limits.

This makes it important to build digital preservation planning into the structure of a site from the beginning. While it is impossible to anticipate every eventuality, it is possible to follow best practices that help maximize the chance that the resource will be accessible well into the future.

Ease of preservation was one of the reasons we decided to build Glam3D.org with the Jekyll framework. Jekyll uses a static site approach. Among other things, that means that there is no traditional backend (such as wordpress or drupal) holding all of the content in a format that is inaccessible to the site’s visitors. Instead, Jekyll uses markdown files - which are human-readable text files - to make each page of the site. It draws images from a folder that is helpfully called “images”.

This approach makes sure that the heart of the site - the text, images, links, and structure - are simply a series of text files, images, and folders that are easy to navigate. Furthermore, all of the files are publicly available (and freely licensed) on the Engelberg Center github page. Anyone can go to the github repo and download all of the files required to make the site. The repo also contains all of the prior versions of the site.

Jekyll itself is open source software. That makes it easy for someone to reproduce the entire site by downloading Jekyll, downloading our repo, and just putting them together. It also means that someone attempting to reproduce the site well in the future will be able to find the version of Jekyll we used to build the site today and modify it to work on whatever computers they have access to.

As part of our digital preservation efforts, we will use Conifer, a web archiving tool by Rhizome, to collect and capture the interactivity of navigating the site as dynamic web content. At moments of substantive updates, we plan to create screen capture tutorials with commentary to provide users of the site an overview of the components. These videos, hosted on the publication site with a Creative Commons Attribution 4.0 license, will also serve as another means to preserve the publication.

Preservation is an evolving practice, so please contact us with your recommendations about other forms of preservation that we should consider.