Tag: tiny2040

Number to Money counter with CircuitPython on Tiny2040

Phil’s working on some interactive electronics for a project, and he was asked to create a counter that could show how much money you could make from 20p recycling deposits using CircuitPython & a Tiny2040

Phil’s working on some interactive electronics for a project, and he was asked to create a counter that could show how much money you could make from 20p recycling deposits. The counter + button in a #circuitPython was easy to implement (see other “weekly project” posts for a “how to”) – But playing an MP3 file has become incredibly easy with CircuitPython, having the library / code built in to the system! so no need to add a new library or even extra electronics to your CircuitPython Powered Board of Choice! (We’ve been using the Raspberry Pi #Pico & the Pimoroni #Tiny2040 )

Below is a short video of the Tiny2040 + button + mono speaker counting up when the counter value is sent to a function that converts it to a list of MP3’s to play.

Tiny2040 + Button + Mono Speaker playing MP3s

Phil took a while to create an algorithm to create a “sentence” that stitches together the necessary files needed… using small MP3 files saved to the 8mb Tiny2040. The numbers 1 to 20 were recorded, then, 30, 40, 50, 60, 70, 80 & 90. Phil also created with a speech synthesiser, “pence”, “and”, “pound”, “pounds” – which can then create any number up to 999 (Thousands + were unnecessary at the moment!) When it reaches “£100” – a clip saying “you’ve made a lot of money, perhaps donate it to charity?” is spoken, then the counter resets !

The code below is Phil’s “Robust” programming… which works nicely, and can even cope with increments of 5p – but single counts break it (his “logic” should be improved – but the 5 / 10 / 20p increments work! 

# SPDX-FileCopyrightText: 2020 Jeff Epler for Adafruit Industries
# Custom Code by Philip Thompson / Digital Maker CIC
# SPDX-License-Identifier: MIT

"""CircuitPython Essentials Audio Out MP3 """
import board
import digitalio
from time import sleep

from audiomp3 import MP3Decoder

try:
    from audioio import AudioOut
except ImportError:
    try:
        from audiopwmio import PWMAudioOut as AudioOut
    except ImportError:
        pass  # not always supported by every board!

button = digitalio.DigitalInOut(board.GP0)
button.switch_to_input(pull=digitalio.Pull.DOWN)


audio = AudioOut(board.A0)
# You have to specify some mp3 file when creating the decoder
mp3 = open("none.mp3", "rb")
decoder = MP3Decoder(mp3)
decoder.file = mp3
audio.play(decoder)

# calculate money from number stuff

def convertArrayToString(a):
    return(' '.join(map(str, a)))

def last_digit(num):
    if 10 < num < 20:  # it's a teen!
        return [str(num)+".mp3"]
    else:
        last_digit_unsigned = abs(num) % 10
        return [str(num)+".mp3"] if last_digit_unsigned == 0 else [str(num)[0]+"0.mp3", "5.mp3"]

# used in making a sentence of the value of the number
ppp = ['pence.mp3']
lb = ['pound.mp3']
lbs = ['pounds.mp3']

def numToMoney(v):
    if v < 20:  # unique "quick returns"
        return([(str(v)+".mp3")] + ppp)
    elif (v > 9999):  # no one will make this much money from recycling!?
        return(["too_much.mp3"])
    elif (15 < v < 100):  # just pence
        return(last_digit(v) + ppp)
    else:
        tupV = str(v)
        if len(tupV) == 3:
            if (tupV[0] == "1"):
                lll = lb
            else:
                lll = lbs
                    
            if (tupV[1] + tupV[2] == "00"):  # flat £                
                return([tupV[0]+".mp3"] + lll)
            else:
                if tupV[1] != "0":  # not a "x pounds tens pence
                    return([tupV[0]+".mp3"] + lll + ["and.mp3"] + last_digit(int(tupV[1]+tupV[2]))+ppp)
                else:
                    return([tupV[0]+".mp3"] + lll + ["and.mp3"] + ["5.mp3"] + ppp)
        else:
            if (tupV[1] + tupV[2] + tupV[3] == "000"):  # flat £
                return([tupV[0]+"0.mp3"] + lbs)
            else:  # complicated number x pounds y (z) pence
                tA = tupV[0] + tupV[1]
                tB = tupV[2] + tupV[3]
                if (tB == "00"):
                    s = [tA+".mp3"] + lbs
                elif (tB == "05"):
                    s = [tA+".mp3"] + lbs + ["and.mp3"] + ["5.mp3"] + ppp
                else:
                    s = [tA+".mp3"] + lbs + ["and.mp3"] + last_digit(int(tB)) + ppp
                return(s)


# res = arr[::-1] #reversing using list slicing
def money(n):
    moneyArray = []
    moneyArray.extend(numToMoney(n))
    #print(moneyArray)
    for w in moneyArray:
        decoder.file = open(w, "rb")
        audio.play(decoder)
        #print("playing", w)
        while audio.playing:
            sleep(0.1)

counter = 0

while True:
    
    while audio.playing:
        pass
    
    if button.value:
        counter += 20
        money(counter)
        sleep(0.3)
        if counter > 9999:
            counter = 0
num_to_money for circuitPythonDownload

The Button is in Pin GP0 & the Speaker Signal Out is in pin A0 … you can’t get simpler! Amazing! MP3 files played with CircuitPython on a Tiny2040 – Done!

Tiny2040 + Old Valve + NeoPixel

Phil is working away on the “Oop Tree” on the Pico, but is getting into “slow progress” with getting to grips with the implementation of how the tree will be affected by various inputs (water, food, light).

So as a “quick show n tell” – he’s put together a quick project using a #pimoroni #tiny2040 microcontroller, again, running the latest version of #circuitPython. Having found a box of old blown Valves (Beautiful objects!) Phil thought he would try to convert them into a useful light, using an RGB led, a button and a sliding potentiometer.

Phil did wire up a classic 4 legged RGB led & got it working, but had some very neat, single “NeoPixels” from Ada Fruit lying around, so soldered some pins onto one & used that, as instead of needing 3 separate pins to control the Red Green & Blue pins, you can do that all through one pin on the NeoPixel. There’s even a handy library to help ease the controls of changing the light colours / intensity.

First, Phil wired the push button into a digital pin (GP7) + Ground, then added a sliding potentiometer (you need 3 connections for this input, a constant 3v, a ground connection, then your “reading” (analogue) connection (A3)). Lastly, phil connected the 3 wires (5v, Gnd + A0) to the NeoPixel. Because you can “chain” NeoPixels, be sure to use the “in” side of the NeoPixel. Phil then drilled a hole into the base of the old Valve, he did this outside (well ventilated) and wore a mask, just in case there are any nasty old chemicals inside the housing or valve itself.

The full code for Phil’s RGB Led can be found here and a wee explanation below:

This project uses a single pushbutton to “cycle through” different states the NeoPixel uses. There is a Dictionary (Dict) that keeps information for LED levels (a “Base” RGB colour + “mix” (potential new levels to be added to the base colour). Each Dict Key is a string that should make the values obvious! The last setting is to make the slider decide what colour the RGB led should be…

Using a few functions Phil wrote for previous projects, you can now pass two tuples (r,g,b) and add them together to return the “mixed” (r,g,b) value – and apply it to the NeoPixel with the simple library method “pixels[0] = (r,g,b)” and “pixels.show()” (to update the NeoPixel).

The slider affects the possible “maximum mix” value by first converting its raw value (130 to 65000+) to 0 & what ever the current maximum value is for that “mix” (stored in the dictionary) this is done for each value (r, g, b). So when the slider is at “0” the maximum possible random number is between 0 & 0 (no new colour added to the base colour!) the higher the slider goes, the more randomness for each Red, Green, Blue “mix” value is possible… so the light starts to flicker within the range of the “base + mix” values…

The Slide setting uses a “wheel” method from Ada Fruit, and we “just” need to map the slide value (again from 130 to 65000+) to 0 & 255. When the slider is moved, it takes its position & passes an RGB value to the Neopixel to cycle from Green to Green over the spectrum. Nice.