VL53L7CX Multizone ToF Sensor for Raspberry Pi Pico 2

A complete implementation of the VL53L7CX multizone Time-of-Flight sensor driver for the Raspberry Pi Pico 2, using the official STMicroelectronics driver adapted for the Pico SDK.

🎯 Features

• 8x8 Multizone Distance Sensing - 64 individual distance measurement zones
• Official ST Driver - Uses the professional STMicroelectronics VL53L7CX Ultra Lite Driver
• Pico 2 Compatible - Custom platform layer for Pico SDK integration
• Real-time Data Output - USB serial output with formatted distance data
• Complete Build System - CMake configuration for easy building

📁 Project Structure

pico2/
├── vl53l7cx_project/           # Main VL53L7CX project
│   ├── main_st_driver.c        # Working ST driver example
│   ├── platform_pico.h/c       # Pico 2 platform layer
│   ├── inc/                    # VL53L7CX API headers
│   ├── src/                    # VL53L7CX API source files
│   ├── CMakeLists.txt          # Build configuration
│   └── STSW-IMG036/           # Original ST driver files
├── main.c                      # Simple blink example
├── CMakeLists.txt              # Root build configuration
└── README.md                   # This file

🔧 Hardware Requirements

• Raspberry Pi Pico 2 (RP2350)
• VL53L7CX Sensor Module (Pololu or similar)
• I2C Connections:
  • SDA: GPIO 4
  • SCL: GPIO 5
  • VCC: 3.3V
  • GND: Ground
• Pull-up Resistors: 4.7kΩ on SDA and SCL lines

🚀 Quick Start

1. Prerequisites

• Raspberry Pi Pico SDK installed
• ARM GCC toolchain
• CMake 3.13+

2. Build the Project

cd vl53l7cx_project
./build.sh

Or manually:

cd vl53l7cx_project
rm -rf build
mkdir build && cd build
cmake .. -DPICO_BOARD=pico2 -DPICO_PLATFORM=rp2350-arm-s
make -j8

3. Program the Pico 2

1. Put Pico 2 in BOOTSEL mode
2. Drag and drop st_driver_example.uf2 to the mounted drive

4. View Output

Connect to serial monitor:

screen /dev/cu.usbmodem23101 115200

📊 Expected Output

VL53L7CX ST Driver Example for Pico 2
=====================================
I2C initialized on pins SDA=4, SCL=5
Checking if VL53L7CX sensor is alive...
VL53L7CX sensor detected!
Initializing VL53L7CX sensor...
VL53L7CX ULD ready ! (Version : VL53L7CX_2.0.0)
Setting sensor to 8x8 mode...
Sensor set to 8x8 mode successfully
Starting ranging...
Ranging started successfully!
Reading distance data from all zones (8x8 grid)...
Press Ctrl+C to stop

Measurement #1:
=== VL53L7CX Zone Distance Data (8x8 grid) ===
Zone distances in mm:
Row 0:  245  230  215  200  185  170  155  140
Row 1:  265  250  235  220  205  190  175  160
Row 2:  285  270  255  240  225  210  195  180
...

🔧 Technical Details

Platform Layer

The project includes a custom platform layer (platform_pico.h/c) that adapts the ST driver from STM32 HAL to Pico SDK:

• I2C Communication: Uses Pico SDK hardware_i2c functions
• Timing: Uses Pico SDK sleep_ms for delays
• Memory Management: Standard C library functions

Key Files

• main_st_driver.c - Complete working example using ST driver
• platform_pico.h/c - Pico 2 platform abstraction layer
• inc/vl53l7cx_api.h - ST VL53L7CX API (modified for Pico)
• src/vl53l7cx_api.c - ST VL53L7CX implementation

I2C Configuration

• Address: 0x29 (configured for your sensor)
• Speed: 400 kHz
• Pins: SDA=4, SCL=5

🛠️ Troubleshooting

Sensor Not Detected

1. Check I2C connections (SDA=4, SCL=5)
2. Verify 3.3V power supply
3. Ensure pull-up resistors are present
4. Check I2C address (should be 0x29)

Build Issues

1. Ensure Pico SDK is properly installed
2. Check CMake version (3.13+)
3. Verify ARM GCC toolchain is available

No Serial Output

1. Wait 2 seconds after programming for USB initialization
2. Check USB cable connection
3. Verify correct serial port (/dev/cu.usbmodem23101)

📚 Additional Examples

The project includes several example programs:

• main_st_driver.c - Full ST driver example (recommended)
• vl53l7cx_driver.c - Custom driver implementation
• test_serial.c - Serial communication test
• simple_blink.c - Basic LED blink test

📄 License

This project includes the official STMicroelectronics VL53L7CX driver, which is licensed under ST's terms. See LICENSE.txt files for details.

🎉 Success!

If you see the 8x8 distance grid output, congratulations! You have successfully implemented a professional-grade multizone ToF sensor system with your Pico 2.

🔗 References

• STMicroelectronics VL53L7CX Datasheet
• Raspberry Pi Pico 2 Documentation
• Pico SDK Documentation