🔌 RSL10-Arduino I2C Communication

Reliable bidirectional I2C communication between RSL10 (master) and Arduino (slave) using software I2C bit-bang implementation.

Embedded systems • Low-level protocols • 3.3V compatible • 90%+ success rate

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📋 Overview

This project implements reliable I2C communication between an ON Semiconductor RSL10-002GEVB (master) and Arduino Nano (slave). The RSL10 uses a software I2C bit-bang implementation, allowing flexible GPIO selection and reliable communication at 30-40 kHz.

🎯 Key Features

Feature	Description
🔧 Software I2C	Bit-bang implementation on RSL10 GPIO
⚙️ Hardware I2C	Native Wire library on Arduino
↔️ Bidirectional	Data transfer with acknowledgment
⚡ 3.3V Logic	Direct connection without level shifters
🔄 Error Handling	Retry logic and status codes
✅ 90%+ Success	Tested and verified reliability

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🏗️ System Architecture

sequenceDiagram
    participant RSL10 as RSL10 (Master)
    participant I2C as I2C Bus
    participant Arduino as Arduino (Slave)

    Note over RSL10,Arduino: Address: 0x55

    loop Communication Cycle
        RSL10->>I2C: START condition
        RSL10->>I2C: Send address + W (0xAA)
        I2C->>Arduino: Address match
        Arduino-->>I2C: ACK
        RSL10->>I2C: Send data byte
        Arduino-->>I2C: ACK
        RSL10->>I2C: STOP condition
        
        Note over Arduino: Process: data + 1
        
        RSL10->>I2C: START condition
        RSL10->>I2C: Send address + R (0xAB)
        Arduino-->>I2C: ACK + response byte
        RSL10->>I2C: NACK + STOP
        
        Note over RSL10: Verify: response == data + 1
    end

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🛠️ Hardware Requirements

Components

Component	Description	Quantity
RSL10-002GEVB	ON Semiconductor dev board	1
Arduino Nano	3.3V or 5V with level shifting	1
Resistors	2.7kΩ for I2C pull-ups	2
Jumper Wires	Male-to-male	4+
Breadboard	For prototyping	1

Pin Connections

RSL10 Pin	Signal	Arduino Pin	Notes
3.3V	VCC	3.3V	⚠️ Use 3.3V only
GND	Ground	GND	Common ground
DIO2	SDA	A4	+ 2.7kΩ pull-up
DIO3	SCL	A5	+ 2.7kΩ pull-up

Wiring Diagram

┌─────────────────────────────────────────────────────────────────┐
│                        I2C BUS WIRING                           │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│    RSL10-002GEVB                         Arduino Nano           │
│    ┌──────────┐                          ┌──────────┐           │
│    │      3.3V├────────────────────────────┤3.3V      │           │
│    │          │                          │          │           │
│    │     DIO2 ├────┬───────────────────┬───┤A4 (SDA) │           │
│    │    (SDA) │    │                   │   │          │           │
│    │          │   ┌┴┐                  │   │          │           │
│    │          │   │ │ 2.7kΩ            │   │          │           │
│    │          │   └┬┘                  │   │          │           │
│    │          │    └───── 3.3V ────────┘   │          │           │
│    │          │                            │          │           │
│    │     DIO3 ├────┬───────────────────┬───┤A5 (SCL) │           │
│    │    (SCL) │    │                   │   │          │           │
│    │          │   ┌┴┐                  │   │          │           │
│    │          │   │ │ 2.7kΩ            │   │          │           │
│    │          │   └┬┘                  │   │          │           │
│    │          │    └───── 3.3V ────────┘   │          │           │
│    │          │                            │          │           │
│    │      GND ├────────────────────────────┤GND       │           │
│    └──────────┘                          └──────────┘           │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

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⚠️ Logic Level Warning

🔴 CRITICAL: Voltage mismatch can damage RSL10!

Configuration	Status
Arduino powered by RSL10 3.3V	✅ Safe
Arduino USB + RSL10 connected	❌ Dangerous
Using level shifter (3.3V ↔ 5V)	✅ Safe
3.3V Arduino variant	✅ Safe

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🚀 Quick Start

1️⃣ Clone Repository

git clone https://github.com/surbalo1/RSL10-Arduino-I2C-Communication.git
cd RSL10-Arduino-I2C-Communication

2️⃣ Upload Arduino Code

# Open arduino_slave/arduino_i2c_slave.ino in Arduino IDE
# Select: Tools > Board > Arduino Nano
# Select: Tools > Port > (your port)
# Click Upload
# Disconnect USB after upload

3️⃣ Setup RSL10 Project

1. Import rsl10_master into Eclipse IDE
2. Build the project
3. Flash to RSL10 using J-Link

4️⃣ Wire Hardware

Follow the wiring diagram above with pull-up resistors.

5️⃣ Monitor Output

RSL10 (SEGGER RTT Viewer):

TX: 0x00 ✓ | RX: 0x01 ✓
[1] TX: 0x01 ✓ | RX: 0x02 ✓
--- Stats: Success=10, Fail=0 ---

Arduino (Serial Monitor @ 115200):

Listening on 0x55
RX: 0x00 (0)
TX: 0x01

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📁 Project Structure

RSL10-Arduino-I2C-Communication/
├── 📄 README.md              # Documentation
├── 📄 LICENSE                # MIT License
│
├── 📁 rsl10_master/          # RSL10 firmware
│   ├── include/              # Header files
│   │   └── i2c_hal.h         # I2C driver interface
│   └── source/               # Source files
│       ├── main.c            # Main application
│       └── i2c_hal.c         # Software I2C implementation
│
├── 📁 arduino_slave/         # Arduino firmware
│   └── arduino_i2c_slave.ino # I2C slave implementation
│
└── 📁 docs/                  # Additional documentation
    ├── wiring_guide.md       # Detailed wiring instructions
    └── troubleshooting.md    # Common issues & solutions

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⚙️ How It Works

Communication Flow

1. RSL10 (Master) sends a byte to Arduino at address 0x55
2. Arduino (Slave) increments the byte and stores response
3. RSL10 reads back the response
4. RSL10 verifies: response == original + 1

Technical Details

Parameter	Value
Slave Address	0x55
I2C Speed	~30-40 kHz
Implementation	Software bit-bang (RSL10)
Read/Write Delay	100ms recommended

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📊 Performance

Metric	Value
I2C Clock	30-40 kHz
Success Rate	90%+ after initial sync
Recommended Delay	100ms between transactions
Wire Length	<20cm recommended

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🔧 Configuration

Adjust I2C Speed

In i2c_hal.c:

#define I2C_DELAY 250  // Higher = slower, more reliable

Change Slave Address

File	Line
Arduino	#define SLAVE_ADDRESS 0x55
RSL10	#define ARDUINO_ADDR 0x55

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🛠️ Development Environment

Tool	Purpose
Eclipse IDE	RSL10 development
RSL10 SDK	ON Semiconductor libraries
J-Link	Debugging & flashing
SEGGER RTT	Debug output
Arduino IDE	Arduino programming

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🐛 Troubleshooting

Issue	Solution
No communication	Check wiring, pull-ups, common ground
Intermittent failures	Increase I2C_DELAY, shorten wires
NACK on all addresses	Verify slave address matches
Noisy signal	Add 100nF capacitor near Arduino

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📄 License

MIT License - see LICENSE file.

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🙏 Acknowledgments

• ON Semiconductor RSL10 SDK
• Arduino Wire library
• Open-source I2C community

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