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
28V (EPR)
36V (EPR)
40V (EPR)
48V (EPR)

The driver supports both Standard Power Range (SPR) and Extended Power Range (EPR) modes. 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 0.1.1