From aada131d7494da706fccfecd7c35980f679a3d5d Mon Sep 17 00:00:00 2001
From: Harith <harith@a5labs.co>
Date: Wed, 22 Jan 2025 18:20:42 +0800
Subject: [PATCH] chore: add 2 bit adder community project

---
 community-projects/2-bit-adder/main.go | 168 +++++++++++++++++++++++++
 1 file changed, 168 insertions(+)
 create mode 100644 community-projects/2-bit-adder/main.go

diff --git a/community-projects/2-bit-adder/main.go b/community-projects/2-bit-adder/main.go
new file mode 100644
index 0000000..1fb2933
--- /dev/null
+++ b/community-projects/2-bit-adder/main.go
@@ -0,0 +1,168 @@
+package main
+
+import (
+	"machine"
+	"time"
+)
+
+// This Go program implements a simple 2-bit binary adder using Adruino microcontroller and LEDs.
+// The user interacts with the system via buttons and touch inputs to select two 2-bit binary numbers,
+// which are then added, with the result displayed on three LEDs.
+
+// Key Features:
+
+// Hardware Components:
+
+// LEDs (Red, Green, Blue): Used to represent numbers (0-7) as binary.
+// Buttons: For user input to cycle through states and confirm selections.
+// Touch Sensor: Used to increment the binary input values.
+
+// Program Flow:
+
+// Initialization: All LEDs are turned on to indicate readiness.
+
+// Input Capture:
+// First 2-bit operand (input1) is selected using the touch sensor.
+// After confirmation, the second operand (input2) is selected.
+// Addition Display: The sum of input1 and input2 is calculated and displayed on the LEDs.
+// Reset: Pressing the button resets the system to accept new inputs.
+
+// User Interaction:
+
+// Button presses and touch inputs guide the program through different states:
+// Selecting the first operand.
+// Selecting the second operand.
+// Displaying the sum.
+// Resetting the program for a new operation.
+
+// To run: tinygo flash -target=nano-rp2040 main.go
+
+var (
+	green  = machine.D12
+	red    = machine.D10
+	button = machine.D11
+	touch  = machine.D9
+	blue   = machine.D8
+)
+
+// numberToLED: Maps a number (0-7) to a binary LED representation.
+// red LED represents the least significant bit. blue LED represents
+// the most significant bit.
+func numberToLED(i uint8) {
+	if i == 0 { // 000
+		red.Low()
+		green.Low()
+		blue.Low()
+	} else if i == 1 { // 001
+		red.Low()
+		green.Low()
+		blue.High()
+	} else if i == 2 { // 010
+		red.Low()
+		green.High()
+		blue.Low()
+	} else if i == 3 { // 011
+		red.Low()
+		green.High()
+		blue.High()
+	} else if i == 4 { // 100
+		red.High()
+		green.Low()
+		blue.Low()
+	} else if i == 5 { // 101
+		red.High()
+		green.Low()
+		blue.High()
+	} else if i == 6 { // 110
+		red.High()
+		green.High()
+		blue.Low()
+	} else if i == 7 { // 111
+		red.High()
+		green.High()
+		blue.High()
+	}
+}
+
+func main() {
+	green.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	red.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	button.Configure(machine.PinConfig{Mode: machine.PinInputPulldown})
+	touch.Configure(machine.PinConfig{Mode: machine.PinInputPulldown})
+	blue.Configure(machine.PinConfig{Mode: machine.PinOutput})
+
+	var isFirstButtonPressed bool
+	var isSecondButtonPressed bool
+	var isThirdButtonPressed bool
+	var isFourthButtonPressed bool
+
+	var input1 uint8
+	var input2 uint8
+
+	for {
+		if !isFirstButtonPressed {
+			// initialize all three leds
+			red.High()
+			green.High()
+			blue.High()
+		}
+
+		if !isFirstButtonPressed && button.Get() {
+			isFirstButtonPressed = true
+			red.Low()
+			green.Low()
+			blue.Low()
+			time.Sleep(time.Millisecond * 500)
+		}
+
+		if isFirstButtonPressed && !isSecondButtonPressed {
+			if touch.Get() {
+				if input1 < 3 {
+					input1++
+				}
+				time.Sleep(time.Millisecond * 500)
+			}
+
+			if button.Get() {
+				isSecondButtonPressed = true
+				numberToLED(input1)
+				time.Sleep(time.Millisecond * 500)
+			}
+		}
+
+		if isSecondButtonPressed && !isThirdButtonPressed {
+			if touch.Get() {
+				if input2 < 3 {
+					input2++
+				}
+				time.Sleep(time.Millisecond * 500)
+			}
+
+			if button.Get() {
+				isThirdButtonPressed = true
+				numberToLED(input2)
+				time.Sleep(time.Millisecond * 500)
+			}
+		}
+
+		if isThirdButtonPressed && !isFourthButtonPressed {
+			if button.Get() {
+				isFourthButtonPressed = true
+				numberToLED(input1 + input2)
+				time.Sleep(time.Millisecond * 500)
+			}
+		}
+
+		if isFourthButtonPressed {
+			if button.Get() {
+				isFirstButtonPressed = false
+				isSecondButtonPressed = false
+				isThirdButtonPressed = false
+				isFourthButtonPressed = false
+				input1 = 0
+				input2 = 0
+				time.Sleep(time.Millisecond * 500)
+			}
+		}
+	}
+}