Project 2: Simulated Indoor Lighting Circuit

🎯 Project Objectives

Build a light switch simulation that:

Uses a push button to toggle a light on/off
Controls a full-color LED to emit white light when "on"
Displays current switch status on screen

📋 Required Hardware

Component	Quantity	Connection
Steamania JoyKit V2	1	Main Controller
Push Button Module	1	Digital Input Pin
WS2812B Full-Color LED	1	On-board or External

🔧 Circuit Setup

Push Button: Connect to one of the digital input pins (e.g., DI0)
WS2812B LED: Use on-board LED or connect to dedicated pin

💡 Core Tasks

Task 1: Configure Button as Digital Input

Use opcode 0x10 to configure IO pins
Set appropriate pin as digital input

Task 2: Implement Toggle Logic

Detect button press (transition from HIGH to LOW or vice versa)
Toggle a state variable (0 = OFF, 1 = ON)
Implement debouncing to avoid false triggers

Task 3: Control LED State

Turn LED white (0xFFFFFF) when switch is ON
Turn LED off (0x000000) when switch is OFF

Task 4: Display Status

Show "ON" or "OFF" text on screen
Optionally display current state indicator

📝 Reference Solution

Program Code

C7 0001 0000  ; Enable WS2812B LED control
10 0025 00F0  ; Configure IO pins: 4 inputs (0-3), 4 outputs (4-7)
10 0020 0000  ; Initialize state variable R20 = 0 (OFF)
10 0021 0000  ; Initialize previous button state R21 = 0
10 0028 FFFF  ; Set foreground color to white (for text)
0E 0000 0010  ; Jump to main loop at line 010

; Main Loop - Start at line 010
14 0000 0000  ; Read digital inputs to R00
17 0000 0001  ; R00 = R00 AND 0x01 (check only DI0)
09 0000 0020  ; If R00 == R00 (button state), jump to line 020
                  ; Actually: compare with previous state in R21

0E 0000 0030  ; Jump to update display (no change detected)

; Button Press Detected - Toggle State
11 0022 0020  ; Copy current button state to R22 (temp storage)
12 0020 0001  ; Toggle R20: if 0 then 1, if 1 then 0 (simplified)
0E 0000 0030  ; Jump to update LED and display

; Update LED and Display - Line 030
04 0000 0040  ; If R00 (state) > 0, jump to turn LED on
E4 0000 0000  ; Turn LED OFF (black)
55 000A 0000  ; Display "OFF" at position (10, 0)
0E 0000 0050  ; Jump to end of loop

E4 00FF FFFF  ; Turn LED ON (white)
55 000A 0001  ; Display "ON" at position (10, 0)

; End of Loop - Line 050
11 0021 0000  ; Store current button state to R21 (previous)
02 0064 0000  ; Delay 100ms for debouncing
0E 0000 0010  ; Jump back to line 010 (main loop)

Improved Solution with Proper Toggle Logic

C7 0001 0000  ; Enable WS2812B LED control
10 0025 00F0  ; Configure IO: lower 4 bits as input, upper 4 as output
10 0020 0000  ; R20 = Light state (0=OFF, 1=ON)
10 0021 0001  ; R21 = Previous button state (1 = not pressed)
10 0028 FFFF  ; Set foreground color to white
0E 0000 0010  ; Jump to main loop

; Main Loop
14 0000 0000  ; Read DI to R00
17 0000 0001  ; R00 = R00 AND 0x01 (check DI0 only)
06 0001 0020  ; If R00 == 1 (button not pressed), jump to 020
06 0001 0050  ; If R00 == 1 (prev state also not pressed), jump to 050

; Button Pressed (transition from 1 to 0)
12 0020 0001  ; Toggle R20 (light state): 0→1 or 1→0
04 0000 0030  ; If R20 > 0 (light ON), jump to 030
E4 0000 0000  ; Turn LED OFF (black)
55 0A00 0000  ; Display "OFF"
0E 0000 0050  ; Jump to update previous state

0E 0000 0050  ; Button not pressed, skip toggle

E4 00FF FFFF  ; Turn LED ON (white)
55 0A00 0001  ; Display "ON"

11 0021 0000  ; R21 = R00 (store current button state)
02 0096 0000  ; Delay 150ms (debounce)
0E 0000 0010  ; Loop back to start

Simplified and Corrected Solution

000 C7 0001 0000  ; Enable WS2812B LED control
001 10 0025 00F0  ; Configure IO pins: bits 0-3 as input, 4-7 as output
002 10 0020 0000  ; R20 = Light state (0=OFF, 1=ON)
003 10 0028 FFFF  ; Set foreground color to white (for text display)
004 0E 0000 0010  ; Jump to main loop at line 010

; Main Loop - Check Button and Update State
010 14 0000 0000  ; Read digital inputs to R00
011 17 0000 0001  ; Mask to get only bit 0 (DI0): R00 = R00 AND 0x01
012 06 0001 0020  ; If DI0 == 1 (button NOT pressed), jump to 020 (skip)

; Button IS pressed (DI0 = 0)
013 12 0020 0001  ; Toggle R20: R20 = R20 + 1 (0→1, 1→2)
014 04 0001 0018  ; If R20 > 1, jump to 018 (reset to 0)
015 0E 0000 0019  ; Jump to update LED

018 10 0020 0000  ; R20 = 0 (reset state)

; Update LED Based on State
019 04 0000 001A  ; If R20 > 0 (ON), jump to 01A
01A E4 0000 0000  ; LED OFF (black)
01B 55 0A00 0000  ; Display "OFF" at (10, 0)
01C 0E 0000 001E  ; Jump to delay

01E E4 00FF FFFF  ; LED ON (white: R=255, G=255, B=255)
01F 55 0A00 0001  ; Display "ON" at (10, 0)

; Delay and Loop
020 02 0096 0000  ; Delay 150ms (debounce)
021 0E 0000 0010  ; Jump back to line 010

Final Optimized Solution (Recommended)

000 C7 0001 0000  ; Enable WS2812B LED control
001 10 0025 00F0  ; Configure IO: lower 4 pins as input
002 10 0020 0000  ; R20 = Light state (0=OFF, 1=ON)
003 10 0021 0001  ; R21 = Previous button state (1=released)
004 10 0028 FFFF  ; Set text color to white
005 0E 0000 0010  ; Jump to main loop

; Main Loop
010 14 0000 0000  ; Read DI to R00
011 17 0000 0001  ; R00 = R00 AND 0x01 (check DI0 only)
012 06 0001 0020  ; If button released (1), jump to 020
013 06 0001 0020  ; If previous also released, skip toggle

; Toggle state on button press
014 12 0020 0001  ; R20 = R20 + 1 (toggle)
015 04 0001 0017  ; If R20 > 1, jump to reset
016 0E 0000 0018  ; Jump to update

017 10 0020 0000  ; Reset: R20 = 0

; Update LED and display
018 04 0000 001A  ; If R20 > 0, turn LED on
019 E4 0000 0000  ; LED OFF
01A 55 0A00 0000  ; Display "OFF"
01B 0E 0000 001D  ; Jump to end

01C E4 00FF FFFF  ; LED ON (white)
01D 55 0A00 0001  ; Display "ON"

; End loop
01E 11 0021 0000  ; R21 = R00 (store button state)
01F 02 0096 0000  ; Delay 150ms (debounce)
020 0E 0000 0010  ; Loop back

🔍 Detailed Explanation

Initialization (Lines 000-005)

Line 000: C7 0001 0000

Enable WS2812B full-color LED control module
Required before using opcode 0xE4

Line 001: 10 0025 00F0

Configure IO pin directions
R25 = IO configuration register
00F0 = Binary 11110000 = Lower 4 pins as input, upper 4 as output

Line 002: 10 0020 0000

Initialize light state variable R20 to 0 (OFF)
R20 will toggle between 0 (OFF) and 1 (ON)

Line 003: 10 0021 0001

Initialize previous button state R21 to 1 (released)
Used for edge detection

Line 004: 10 0028 FFFF

Set foreground color to white (0xFFFF in RGB565)
Used for text display

Line 005: 0E 0000 0010

Jump to main loop at line 010

Button Detection and Toggle (Lines 010-017)

Line 010: 14 0000 0000

Read digital input values to R00
Each bit represents one DI pin status

Line 011: 17 0000 0001

R00 = R00 AND 0x01
Mask to check only DI0 (bit 0)
Result: R00 = 0 (pressed) or 1 (released)

Line 012: 06 0001 0020

If R00 == 1 (button released), jump to 020
Skip toggle logic when button not pressed

Line 013: 06 0001 0020

If previous state also released, skip
This creates edge detection (only toggle on press, not hold)

Line 014: 12 0020 0001

Toggle light state: R20 = R20 + 1
Alternates between 0 and 1

Line 015: 04 0001 0017

If R20 > 1, jump to reset line 017
Ensures R20 stays in range 0-1

Line 016: 0E 0000 0018

Jump to LED update section

Line 017: 10 0020 0000

Reset R20 to 0 (wraps around from 2 to 0)

LED Control (Lines 018-01D)

Line 018: 04 0000 001A

If R20 > 0 (light is ON), jump to 01A

Line 019: E4 0000 0000

Turn LED OFF
RGB = (0, 0, 0) = Black

Line 01A: 55 0A00 0000

Display "OFF" text at position (10, 0)
Value 0000 represents OFF state

Line 01B: 0E 0000 001E

Jump to end of loop

Line 01C: E4 00FF FFFF

Turn LED ON
RGB = (255, 255, 255) = White

Line 01D: 55 0A00 0001

Display "ON" text at position (10, 0)

Loop Management (Lines 01E-020)

Line 01E: 11 0021 0000

Store current button state to R21
R21 = R00 (save for next iteration)

Line 01F: 02 0096 0000

Delay 150 milliseconds
0096 = 150 in decimal
Provides debouncing to prevent false triggers

Line 020: 0E 0000 0010

Jump back to line 010
Creates infinite loop for continuous monitoring

🎨 State Transition Table

Current State	Button Press	New State	LED Action
OFF (0)	Pressed	ON (1)	Turn ON (White)
ON (1)	Pressed	OFF (0)	Turn OFF (Black)
OFF (0)	Not Pressed	OFF (0)	No change
ON (1)	Not Pressed	ON (1)	No change

🔍 Key Learning Points

Digital Input Reading: How to read button states from IO pins
Edge Detection: Detecting button press vs. button hold
Toggle Logic: Implementing on/off state machine
Debouncing: Preventing false triggers with delays
Conditional Control: Using comparisons for decision making
RGB Color: Setting LED colors for different states

🧪 Testing Checklist

Button is properly configured as digital input
LED turns on (white) when button is pressed
LED turns off when button is pressed again
Display shows correct "ON" or "OFF" status
Button debouncing works (no false triggers)
System responds reliably to repeated presses

💡 Extension Challenges

Add Dimming: Use button hold to adjust LED brightness
Multiple Colors: Cycle through different colors instead of just on/off
Dual Button System: Add separate on and off buttons
Auto-Off Timer: Automatically turn off after 5 minutes
Status Indicator: Add a second LED to show power status
Remote Control: Use infrared or Bluetooth for wireless control

🐛 Common Issues and Solutions

Issue 1: LED Flickers Rapidly

Cause: No debouncing or insufficient delay Solution: Increase delay time (line 01F) to 200-300ms

Issue 2: Button Doesn't Respond

Cause: Incorrect IO configuration Solution: Verify line 001 sets correct pins as input

Issue 3: LED Toggles Multiple Times

Cause: Button bounce or delay too short Solution: Increase debounce delay or add additional filtering

Issue 4: Display Shows Wrong Text

Cause: Incorrect state variable or comparison Solution: Check R20 value and comparison logic

Instructions Used in This Project

Opcode	Name	Description	Documentation Link
`0x02`	Delay	Set delay time in milliseconds	Delay
`0x04`	Greater Than Jump	Jump if R00 > immediate value	Conditional Jumps
`0x06`	Equal Jump	Jump if R00 == immediate value	Conditional Jumps
`0x0E`	Unconditional Jump	Jump to specified line	Unconditional Jump
`0x10`	Write Register	Write immediate value to register	Register Operations
`0x11`	Copy Register	Copy value from one register to another	Register Operations
`0x12`	Add Register	Add immediate value to register	Register Operations
`0x14`	Read DI	Read digital input pins to R00	Digital I/O
`0x17`	AND Register	Bitwise AND operation	Bitwise Operations
`0x55`	Display Text	Display register value on screen	Text Output
`0xCB`	Enable WS2812B	Enable LED control module	External Devices
`0xE4`	Set LED Color	Set RGB color for specific LED	Lights & Music

Additional Reference

IO Configuration Register (R25) - Pin direction control
Register Map - Complete register documentation
Instruction Set Summary - Full instruction set overview

🎯 Project Objectives​

📋 Required Hardware​

🔧 Circuit Setup​

💡 Core Tasks​

Task 1: Configure Button as Digital Input​

Task 2: Implement Toggle Logic​

Task 3: Control LED State​

Task 4: Display Status​

📝 Reference Solution​

Program Code​

Improved Solution with Proper Toggle Logic​

Simplified and Corrected Solution​

Final Optimized Solution (Recommended)​

🔍 Detailed Explanation​

Initialization (Lines 000-005)​

Button Detection and Toggle (Lines 010-017)​

LED Control (Lines 018-01D)​

Loop Management (Lines 01E-020)​

🎨 State Transition Table​

🔍 Key Learning Points​

🧪 Testing Checklist​

💡 Extension Challenges​

🐛 Common Issues and Solutions​

Issue 1: LED Flickers Rapidly​

Issue 2: Button Doesn't Respond​

Issue 3: LED Toggles Multiple Times​

Issue 4: Display Shows Wrong Text​

📚 Related Documentation​

Instructions Used in This Project​

Additional Reference​