💰 Receipt Detective

A cashier at a boutique is tasked to verify the validity of a transaction using an RN (Reference Number). To do this, she manually creates a link using an RN and the last 8 digits of their account number.

Template Link:
https://apps.cbe.com.et:100/?id=<REFERENCE NUMBER><LAST 8 DIGITS>

Boutique's last 8 digits: 61108592
Example RN: FT24341HNN9T

Receipt Link:
https://apps.cbe.com.et:100/?id=FT24341HNN9T61108592

🥅 Goal: Given the account number of the boutique is always the same, let you take as an input the RN from a user and verify the transaction.

🐾 Steps:
- take RN as input from user
- use the RN and 8 last digits of the account number to build the receipt URL
- let your code download the PDF receipt using the URL
- load the PDF and obtain its contents as text (example here)
- extract useful information and do the verification

📅 Submissions: Sunday Morning, 2:00 LT

🪁 Send your submissions in the comments!

@WeeklyCoder | Week 59

🤚🖍 Wo wo wo! But can you paint?

Let's build a simple paint app this week. Much like MS Paint, let it allow to draw, erase, and save on a digital canvas.

🥅 Goal: create a program that allows users to draw on a canvas with the following features:
- brush Tool: Choose a shape (circle, square, triangle, or plus) to draw with.
- brush size: Offer finite options for brush sizes.
- color tool: Choose a color (could be random or via a color picker/input dialog).
- eraser tool: Erase parts of the drawing.
- clear canvas: An option to start fresh.

✏️ Recommended Learning:
- mouseX, mouseY, pmouseX, pmouseY
- mousePressed, mouseReleased, mouseDragged
- point (), line ()
- saveFrame ()

🪁 Submit your creations in the comments!

@WeeklyCoder | Week 60

✅ The To-Not-Do List

A "to-not-do list" is a list of things you want to avoid doing. Whether that's unhelpful habits or vices, the goal is to eliminate unproductive activities to free up time for what truly matters.

🤔 We're borrowing Charlie Munger's Inversion Thinking this week. Instead of asking how to succeed, ask how to fail and then avoid those pitfalls.

🥅 Goal: create a program that helps users manage their unproductive habits by tracking what they successfully avoided in a day

✏️ Example of a to-not-do list:
- binge Social Media for more than 30mins
- procrastinate — do not start that assignment
- stay up and wake up late
- hit snooze button when alarm goes off
- drink less than 2L water a day
- do not participate in WeeklyCoder

⚙️ Task: here

🔨 Usage: here

✏️ Recommended Learning:
- IntDict (Str - int pair — 1 check, 0 uncheck)
- input handling
- mouseClicked
- keyTyped

⚡️ Introduce streaks, badges, and progress indicators.

🪁 Submit your code in the comments!

@WeeklyCoder | Week 61

🎾 Let's bounce!

This week's challenge is a game that hardly needs a description. Watch and recreate!

✏️ Recommended Learning:
- variables, arithmetic & logical operators
- background, mouseClicked, functions

⚡️ Use APDE to make a real Android game from your Processing sketch!

🪁 Submit your code in the comments!

@WeeklyCoder | Week 62

🏎 Tap Snap

This week, let's see how quickly you can respond to a visual stimulus. The rule is simple, tap your screen the moment a shape appears.

🥅 Goal:
Create a game that measures and displays a player's reaction time after showing a shape on the screen for a random duration.

🎮 Game Flow:
1. A random delay hides the shape
2. The shape appears on the screen
3. Player reacts by tapping their screen
4. The program records and displays the reaction time (best time & last time)

⚙️ Random Time Boundary: use 500ms (min time) - 3500ms (max time)

✏️ Recommended Learning:
- millis ()
- text (), textSize (), textAlign ()
- random ()
- casting
- if, mousePressed

⚡️ Bring the Thunder: here

🎁 Special gifts for any 3 who first recreate the game and set sub-200ms, sub-150ms, and sub-130ms reaction times! Only until Christmas!

🪁 Submit your code in the comments!

@WeeklyCoder | Week 63

🐍 Psst ...

How are we on week 64 without having made a snake game already? Beats me!

🥅 Goal: Recreate the classic Snake game.

✏️ Recommended Learning:
- Arrays or Lists
- PVector
- Loops
- keyPressed (), keyCode

🪁 Submit your code in the comments!

@WeeklyCoder | Week 64

🧩 It's Anagram time!

An anagram is a word, phrase, or name formed by rearranging the letters of another, such as "cinema" formed from "iceman."

🥅 Goal:
- Create a program that, given a word, finds all possible anagrams from a predefined list or dictionary.

🎮 Game Flow:
- user inputs a word
- the program searches through a dictionary for words that are anagrams of the input
- display all found anagrams or a message if none exist

⚙️ Words List: here [370,000 + words]

✏️ Recommended Learning:
- loadStrings (),
- .sort (),
- loops and nested loops,
- List

🪁 Submit your code in the comments!

@WeeklyCoder | Week 65

📞 DTMF Tones!

The Dual-Tone Multi-Frequency (DTMF) system is how phones dialers send signals to dial numbers.

These signals are commonly heard on telephone dial pads. Each tone is simply the sum of two sine waves — one from a low-frequency group and one from a high-frequency group.

🎵 Listen to a sample dial tone here.

🌐 Click here and interact with an online DMTF generator.

🥅 Goal: create a program that accepts a phone number as input and produces tones for each digit as if it were pressed on a physical phone keypad. Include pauses between tones for clarity.

🦶 Get started

⚙️ Recommended Learning:
- Array/ArrayList
- Minim Library — for sound generation using oscillators like Oscil
- PVector — for paired digits
- .toCharArray (), .indexOf (), str (), — for String manipulation
- delay () — add pauses between tones

👌 This is the first part of a two-part challenge for an epic project we'll complete next week. Can you guess what part 2 will be?

🪁 Submit your code in the comments!

@WeeklyCoder | Week 66

📞 DTMF Tones 2!

In the TV series Fringe (Season 1 Episode 19 - 36:00-36:44), Olivia hears dialing tones from an abduction's recording and uses an app to decode them into the phone number that was called. By tracing this number, she identifies the perpetrator, pushing the investigation forward.

Let's continue on last week's challenge and create a similar tool this time.

🎵 Listen to a sample dial tone here.

🥅 Goal: create a program that accepts dialing tones as an input (.wav file or other) and outputs the numbers decoded.

⚙️ Recommended Learning:
- Array/ArrayList
- Minim Library — for sound generation using oscillators like Oscil

🪁 Submit your code in the comments!

@WeeklyCoder | Week 67

🖥 It's your turn, again.

Let's have an open projects submission this week. What projects have you been working on since last time?

Whether that's a small one hour project or one that took weeks to finish, let you submit your best (max. of 3) projects here.

Share your works in the comments.

@WeeklyCoder | Week 68

🎧 M is for Music and L is for Lyrics

Let's use the Genius API to create a lyrics fetching project this week.

🥅 Goal: Create a program that, given the name of a song, fetches its lyrics and displays it.

⚙️ It takes < 1min to authorize Genius and obtain your Access Token. You may benefit from using the PY library lyricsgenius or you could just do HTTP.

🪁 Submit your code in the comments!

@WeeklyCoder | Week 69

📍 Near Ping

Case: After boarding the taxi and a few kilometers away, your friend calls to check if you bought the phone case they asked for while you were near the market—🤦‍♀️, you forgot, and now you feel bad. If only something had reminded you when you were near the phone center!

We’re re-revisiting the Haversine formula to calculate the distance between two points on Earth’s surface using latitude and longitude coordinates.

🥅 Goal:
To build an app that allows users to add reminders tied to specific locations (lat & lng) and reminders them when their current location is within 1 kilometer of a reminder’s location.

To keep it simple, store your data in a local file where each reminder has a task (string) and coordinates (latitude, longitude as floats).

🐾 Steps:
- Allow user to enter reminders and store them (e.g., task, latitude, longitude)
- Let user enter their current location
- Check current location against all reminders and display tasks if within 1 km.

➕ Testing coordinates:
Reminder: Buy phone case
Shop: 9.020274156181737, 38.801150775048335
Your Location: 9.020383152979795, 38.800234352160246

✏️ Recommended Learning:
- Haversine Formula
- asin(), sin(), cos()
- sqrt(), pow(), radians()
- lists, dictionaries

⚡️ Bring the thunder!
As with many of the challenges here, nothing's stopping you from making this a full-fledged mobile app.
- Fetch current location from device's GPS
- Push notifications when near a reminder spot
- Allow custom distance for nearness calculation
- Use your friend's live location so that you don't unknowingly pass by a friend you've been meaning to meet next time

🪁 Send your submissions in the comments!

@WeeklyCoder | Week 70

🌔 What did the Moon look like on your birthday?

The Moon cycles through phases—new, waxing, full, and waning—each altering its glow and shadow over about 29.5 days.

With the AstronomyAPI, you can reveal the Moon’s appearance for any specific day and location.

🥅 Goal: Given a date (YYYY-MM-DD) and coordinates (LAT, LNG), write a program to fetch and display the Moon’s image for that moment.

⚙️ Sign up (takes < 2 minutes) to create your Application and get its ID and Secret—check this guide for details.

✏️ Recommended Learning:
- http.requests
- java.util.base64
- JSONObject, .setString (), .setJSONObject (), .getJSONObject ()
- loadImage (), image ()

🪁 Submit your code in the comments!

@WeeklyCoder | Week 71

👟 Kids' Shoe Fit Finder

Kids’ feet grow fast—up to 1-2 sizes a year—making online shoe shopping a guessing game, with over 30% of returns due to fit issues.

To help with this, let's make a program where parents input their child’s age and foot length (cm) and get instant US, UK, and EU sizes.

We'll use Adidas's Kids Shoes Size Chart as a reference.

🥅 Goal: Given age of a child and their foot length (cm), write a program to output shoe size (in US, UK, and EU).

✏️ Recommended Learning:
- arrays
- selection statements
- logical & relational operators
- loadJSONObject, JSONObject, JSON

🪁 Submit your code in the comments!

@WeeklyCoder | Week 72

🥧 Happy Pi Day!

Let's return to visual coding challenges and tackle Circle Packing this week.

In geometry, circle packing is the study of the arrangement of circles (of equal or varying sizes) on a given surface such that no overlapping occurs and so that all circles touch one another.

There are different variations of CP. What kind would you come up with? Excited to see.

✏️ Recommended Learning:
- random (), translate (), circle ()
- PI, TWO_PI
- constrain (), cos (), sin (), dist ()
- List, class, functions, methods

🪁 Submit your code in the comments!

@WeeklyCoder | Week 73

⌨️ Case Shifter

What do you do to fix the casing of an already written text? Probably rewrite it properly. This wastes time when you need it polished fast.

To tackle this, let’s build a program where you highlight text, press the Shift key, and cycle through lowercase, uppercase, or title case like in this video.

🥅 Goal: Given highlighted text, write a program to cycle through case options and replace the highlighted text.

✏️ Recommended Learning:
- .lower(), .upper(), .title()
- conditionals & loops
- libraries: pyperclip, keyboard

🪁 Submit your code in the comments!

@WeeklyCoder | Week 74

⌨️ Withholding Calculator

Better late than never — this week 🙈

It's not rare that you find tools that apply for other countries but none exist for Ethiopian contexts. Such is the case with this week's challenge.

When dealing with financial transactions, manually calculating VAT and withholding tax can be tedious and error-prone.

This week, let’s create a program that takes a post-VAT or pre-VAT price, calculates the pre-VAT/post-VAT amount, and applies withholding tax if thresholds are met (10,000 for products, 3,000 for services), displaying then both the net payable amount and the withheld amount.

🥅 Goal: Given a price, provide selection for pre/post VAT and product/service options. Then calculate the post/pre VAT, withholding amount and net amount. See example calculation here or make a copy of this Sheets template.

✏️ Recommended Learning:
- arithmetic operators
- selection statements (if/else statements)
- functions for reusability

🪁 Submit your code in the comments!

@WeeklyCoder | Week 75

🕰 Pendulum Swings

In many scientific and engineering scenarios, especially when dealing with larger swings, the basic formula for a pendulum's period isn't accurate enough. This week, let's use a more precise calculation that takes into account the initial angle of release.

🥅 Goal: Create a program that calculates the period of a simple pendulum, incorporating a correction for large initial angles using the expansion series for the complete elliptic integral of the first kind (K(k)).

The program should take the pendulum's length and the initial release angle as input and output the more accurate period.

Here's the formula for K(k) we'll use.

✏️ Recommended Learning:
- Arithmetic operators
- Math functions (sqrt, sin, pow)
- Loops
- Functions

🪁 Submit your code in the comments!

@WeeklyCoder | Week 76

🎮 It's Brick Breaker time!

The Brick Game is a dedicated handheld game that displays games in 10 x 20 grid screen. It was popularized in the early 1990s after being introduced in China in 1989.

🥅 Goal: Create a mini clone of the game Block Breaker but in the theme of Brick Games.

You may build on top of this barebones.
Grab a fitting font from here.
Download the Android app from here.

✏️ Recommended Learning:
- text, rectMode
- keyPressed, mousePressed
- loops, selection statements
- functions

🪁 Submit your code in the comments!

@WeeklyCoder | Week 77

🤖 It's Machine Learning time!

Let's get a glimpse of the world of computer vision this week — through a practical application with a problem that hits close to home.

Manually cropping faces from photos using photo editing software is time-consuming. The task this week is, to automate this process using machine learning-based face detection to produce square, face-centered images for an ID-making software.

⚙️ Task breakdown:
- Detect faces in each photo using OpenCV
- Crop each face into a square image, ensuring the face is centered with a padding
- Output square images suitable for ID-making software

This streamlines ID photo preparation, saving time and ensuring consistent output.

🎒 Resources:
- OpenCV for Processing
- Get started with this code

✏️ Recommended Learning:
- loadImage (), image (), save ()
- mask (), copy (), PGraphics

⚡️ Bring the Thunder!
- support for slightly rotated photos
- support for mass photo processing

🪁 Submit your code in the comments!

@WeeklyCoder | Week 78