AP33772S Driver

A platform-agnostic Rust driver for the AP33772S USB Power Delivery (USB-PD) Sink Controller.

Features

Platform-agnostic: Built on embedded-hal traits for maximum compatibility
USB-PD Support: Full support for USB Power Delivery negotiation
SPR and EPR: Supports both Standard Power Range (SPR) and Extended Power Range (EPR) modes
Programmable Power: Support for Programmable Power Supply (PPS) and Adjustable Voltage Supply (AVS)
Protection Features: Built-in over-voltage, over-current, over-temperature, and under-voltage protection
no_std Compatible: Works in embedded environments without heap allocation (with alloc feature)

Supported Voltages

The AP33772S supports negotiation for the following standard voltages:

5V (USB-PD default)
9V
12V
15V
20V (and higher with EPR)

Custom voltages and currents are also supported through programmable PDOs.

Quick Start

Add this to your Cargo.toml:

[dependencies]
ap33772s-driver = "0.1"

For std environments, enable the std feature:

[dependencies]
ap33772s-driver = { version = "0.1", features = ["std"] }

Example Usage

use ap33772s_driver::{AP33772S, PDVoltage};

// Create driver instance
let mut pd_controller = AP33772S::new();

// Initialize the controller (requires I2C implementation)
pd_controller.init(&mut i2c)?;

// Request 12V from the USB-PD source
pd_controller.request_voltage(&mut i2c, PDVoltage::V12)?;

// Read current status
let status = pd_controller.get_status(&mut i2c)?;
println!("Voltage: {}mV, Current: {}mA", status.voltage_mv, status.current_ma);

// Request custom voltage/current (if supported by source)
pd_controller.request_custom_voltage(&mut i2c, 15000, 2000)?; // 15V, 2A

// Get available power capabilities
for pdo in pd_controller.get_pdo_list() {
    println!("PDO {}: {}mV, {}mA, {}mW", 
        pdo.pdo_index, pdo.voltage_mv, pdo.current_ma, pdo.max_power_mw);
}

Platform Integration

This driver uses the embedded-hal I2C traits, making it compatible with any platform that provides an I2C implementation. Here are examples for popular platforms:

ESP32 (esp-idf-hal)

use esp_idf_hal::i2c::*;
use ap33772s_driver::AP33772S;

// Set up I2C
let i2c_config = I2cConfig::new().baudrate(100.kHz().into());
let mut i2c = I2cDriver::new(peripherals.i2c0, sda_pin, scl_pin, &i2c_config)?;

// Use the driver
let mut pd_controller = AP33772S::new();
pd_controller.init(&mut i2c)?;

STM32 (stm32f4xx-hal)

use stm32f4xx_hal::i2c::I2c;
use ap33772s_driver::AP33772S;

let mut i2c = I2c::new(/* I2C peripheral setup */);
let mut pd_controller = AP33772S::new();
pd_controller.init(&mut i2c)?;

Raspberry Pi (rppal)

use rppal::i2c::I2c;
use ap33772s_driver::AP33772S;

let mut i2c = I2c::new()?;
let mut pd_controller = AP33772S::new();
pd_controller.init(&mut i2c)?;

Error Handling

The driver uses a comprehensive error type that wraps the underlying I2C errors:

match pd_controller.request_voltage(&mut i2c, PDVoltage::V12) {
    Ok(()) => println!("Voltage request successful"),
    Err(ap33772s_driver::Error::Timeout) => println!("PD negotiation timed out"),
    Err(ap33772s_driver::Error::NegotiationFailed) => println!("PD negotiation failed"),
    Err(ap33772s_driver::Error::ProtectionFault) => println!("Protection fault occurred"),
    Err(e) => println!("Other error: {:?}", e),
}

Register Map

The driver provides access to all AP33772S registers through constants:

Status and Control: REG_STATUS, REG_CONFIG, REG_SYSTEM
Measurements: REG_VOLTAGE, REG_CURRENT, REG_TEMP
Power Delivery: REG_VREQ, REG_IREQ, REG_PD_REQMSG
Source Capabilities: REG_SRCPDO, REG_SRC_SPR_PDO1..REG_SRC_EPR_PDO13

Protection Features

Configure the built-in protection features:

// Enable all protections
pd_controller.configure_protections(
    &mut i2c,
    true,  // Under-voltage protection
    true,  // Over-voltage protection  
    true,  // Over-current protection
    true,  // Over-temperature protection
    true   // De-rating function
)?;

Power Data Objects (PDOs)

The driver automatically enumerates all available PDOs from the connected source:

for pdo in pd_controller.get_pdo_list() {
    println!("PDO {}: {}V @ {}A ({}W) - {}", 
        pdo.pdo_index,
        pdo.voltage_mv as f32 / 1000.0,
        pdo.current_ma as f32 / 1000.0,
        pdo.max_power_mw as f32 / 1000.0,
        if pdo.is_fixed { "Fixed" } else { "Programmable" }
    );
}

Advanced Features

VOUT Control

Control the output voltage manually:

// Auto control (default)
pd_controller.set_vout_auto_control(&mut i2c)?;

// Force output off
pd_controller.force_vout_off(&mut i2c)?;

// Force output on
pd_controller.force_vout_on(&mut i2c)?;

Hard Reset

Perform a USB-PD hard reset:

pd_controller.hard_reset(&mut i2c)?;

Specifications

I2C Address: 0x52 (7-bit)
I2C Speed: Up to 400kHz
Supply Voltage: 3.3V or 5V
Temperature Range: -40°C to +85°C
USB-PD Compliance: USB-PD 3.1 compatible

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

ap33772s-driver 0.1.0