MP2722 Driver Library

C/C++ platform-agnostic driver for the MP2722 (MPS) battery charger. Featuring I2C control and status monitoring, NVDC power path management and USB-C DRP management.

Features

• Customizable/Portable — Just provide an I2C interface and a log callback to setup the driver on your platform.
• Pre-set/Ready-to-use — Built-in I2C/logging setup for Arduino (Wire/Serial), ESP-IDF (i2c_master/esp_log), STM32 (HAL/UART) and Linux (i2c-dev/stderr), if you don't set it up yourself.
• Optional logging — Configurable log levels (DEBUG, INFO, WARN, ERROR or NONE) supporting a custom log callback.
• Fully fledged — Full status/fault readout: USB Type-C CC detection, legacy/non-standard USB detection, JEITA NTC, charger state, fault state, etc. You can refer to the register map for the complete list of available status and fault registers.
• Linux Compatible — out-of-the-box compatibility with any Linux i2c-dev enabled environment, which is standard on most PCs and SBCs (Raspberry Pi, BeagleBone). (/dev/i2c-X).

Quick Start

Supported platforms and setup requirements

Platform	I2C	Logging	Setup required
Arduino	Wire	Serial	Serial.begin() + Wire.begin()
ESP-IDF	i2c_master	ESP_LOGx	mp2722_platform_set_i2c_handle()
STM32 HAL	HAL_I2C_Mem_*	HAL_UART_Transmit	mp2722_platform_set_i2c_handle() + set_uart_handle()
Linux	/dev/i2c-1	stderr	mp2722_platform_set_i2c_bus("BUS_ADDRESS")
Windows/macOS	—	stderr	Provide your own wrappers
Other	—	—	Provide your own wrappers

Using the 'ready-to-go' supported platforms (Arduino, ESP-IDF, STM32CubeMX, Linux host)

For the ones that DON'T use I2C/UART handle or bus address (e.g., Arduino Wire):

#include "MP2722.h"

MP2722 pmic; // Declare the driver instance globally on supported platform

void pmic_init() // Call this after usual platform setup (Serial, Analog/Digital I/O, I2C, etc.)
{
   // (Optional) Enable built-in driver logging on supported platforms
   pmic.setLogCallback(MP2722_LogLevel::DEBUG);

   // All functions returns MP2722_Result::OK on success or other MP2722_Result on failure
   pmic.init(); // In a real application you should only proceed if this returns OK

   // Standard 3.7-4.2V 2100mAh Li-ion/Li-Po battery in ~0.5C charge rate.
   pmic.setChargeVoltage(4200); // mV = 4.2V @ CV (Constant Voltage) Phase - Basic config
   pmic.setChargeCurrent(1000); // mA = 1A @ CC (Constant Current) Phase - Basic config
   pmic.setCharging(true); // Enable charger (off by default as basic config is required)

   // Note: Hardware watchdog is active by default (40s). Ensure watchdogKick() is called in your main loop.
}

For the ones that DO use I2C/UART handle or bus address (e.g., ESP-IDF I2C Master, STM32 HAL, Linux host):

#include "MP2722.h"

MP2722 *pmic = nullptr; // Declare a pointer for the driver instance globally

void pmic_init() // Call after usual platform setup (Serial, Analog/Digital I/O, I2C, etc.)
{
   // Set the appropriate handles or bus address for your platform
   mp2722_platform_set_i2c_handle(i2c_device_handle); // Only if your platform uses I2C handle
   mp2722_platform_set_uart_handle(uart_device_handle); // Only if your platform uses UART handle
   mp2722_platform_set_i2c_bus("/dev/i2c-1"); // Only if you're on Linux, replace with your correct bus address

   // Now that the platform I2C/UART handle/bus is set, create the driver instance
   pmic = new MP2722();

   /// -- From now on actual driver usage remains the same, besides now dealing with a pointer ('->' not '.') --
   // pmic->setLogCallback(MP2722_LogLevel::DEBUG);

   // Note: Hardware watchdog is active by default (40s). Ensure watchdogKick() is called in your main loop.
}

Using manual platform implementation

#include "MP2722.h"

// Declare the driver instance globally providing custom wrappers for your platform's I2C read/write functions
MP2722 pmic({ your_i2c_write_function, your_i2c_read_function });

void pmic_init() // Call after usual platform setup (Serial, Analog/Digital I/O, I2C, etc.)
{
   // (Optional) Enable driver logging providing a custom wrapper for your platform's logging function
   pmic.setLogCallback(MP2722_LogLevel::DEBUG, your_log_function);

   /// -- Actual driver usage remains the same --
   // Note: Hardware watchdog is active by default (40s). Ensure watchdogKick() is called in your main loop.
}

Note: the I2C function pointers should match MP2722_I2C and the log MP2722_LogCallback signatures. For the I2C read/write both functions should return 0 on success and non-zero on failure. See the examples folder for complete implementation examples.

Watchdog Timer (heartbeat)

The MP2722 has a built-in watchdog timer that is enabled by default and has an expiration time of 40 seconds, requiring periodic "kicks" to prevent it from resetting the device. It is recommended watchdogKick() method should be called at least once every 30 seconds or less to keep the watchdog from expiring. You can call this in your main loop or set up a timer to call it at regular intervals. You can also disable the watchdog if you don't need it, but it's generally recommended to keep it enabled for safety in case of software crashes or unresponsive states.

// From your main application loop at a set interval of 30 seconds or less
pmic.watchdogKick(); // Reset the watchdog timer to prevent PMIC reset. You can also disable this.

Additional notes

• Some parameters such as trickle charge and pre-charge are automously handled by the IC, so unless you know you have a specific need, you don't have to worry about them. Simply set the CV/CC only and the IC will automatically manage appropriate charging phases. You can read the charger status (pmic.getChargerStatus()) to keep track of the details. And you can refer to the MP2722 datasheet to know more about the charging process and how the IC behaves.

• DRP/OTG boost mode (port can power devices) is enabled by default based on USB detection, automatically deactivating on low battery. But you can control both things manually if needed (see the API Reference for details).

Reading data

To read charger status, faults, etc. you can call getStatus() at any time:

// Declare a PowerStatus struct to hold the readout
PowerStatus status{};

// Call from your main app loop at some interval to monitor status/faults, etc.
pmic.getStatus(status); // or pmic->getStatus(status) if using pointer instance

// Do whatever with the status (log, update a LED or display, etc.)
switch (status.charger_status)
{
   case ChargerStatus::NOT_CHARGING:
      // Handle not charging state
      break;
   case ChargerStatus::CHARGE_DONE:
      // Handle charge done state
      break;
   default:
      // Handle charging state (pre-charge, fast charge, etc.)
      break;
}

Installation

PlatformIO

Add to your platformio.ini:

lib_deps =
    https://github.com/erikgs/MP2722-driver.git#main

PlatformIO auto-detects the library in the MP2722/ subfolder.

Arduino

Clone into your Arduino libraries folder:

cd ~/Arduino/libraries
git clone https://github.com/erikgs/mp2722-driver.git

Or in the Arduino IDE: Sketch → Include Library → Manage Libraries… → search "MP2722".

ESP-IDF Component

Move/copy or symlink mp2722/ inside components/ in your project, manually or using git submodule:

git submodule add https://github.com/erikgs/mp2722-driver.git components/driver_mp2722

STM32 or Other (CubeIDE / CMake)

Move/copy or symlink mp2722/ inside libs/ in your project, manually or using git submodule:

git submodule add https://github.com/erikgs/mp2722-driver.git libs/driver_mp2722

• Add MP2722.cpp and MP2722_platform.cpp to your source list
• Add the directory containing these files (libs/driver_mp2722/src/) to your compiler's include path

API Reference

Method	Description
setLogCallback(level, callback)	Set logging callback and max level (nullptr to disable)
init()	Probe device, apply safe defaults (charging off, IIN_MODE=follow-limit), enable buck, auto-OTG, auto-D+/D−, boost-stop-on-low
reset()	Reset all registers to defaults
setChargeVoltage(mv)	Set battery regulation voltage (3600–4600 mV, step 25 mV). Note: Values rounded down to nearest step.
setChargeCurrent(ma)	Set fast-charge current (80–5000 mA, step 80 mA). Note: Values rounded down to nearest step.
setInputCurrentLimit(ma)	Override input current limit (100–3200 mA, step 100 mA). Note: Values rounded down to nearest step.
setCharging(enable)	Enable/disable charging (requires voltage & current set first)
setBuck(enable)	Enable/disable buck converter
setBoost(enable)	Force enable/disable OTG boost
setAutoOTG(enable)	Enable/disable automatic OTG based on USB detection
setBoostStopOnBattLow(enable)	Latch-off boost on low battery vs. interrupt only
forceDpDmDetection()	Trigger immediate D+/D− source detection
setAutoDpDmDetection(enable)	Enable/disable automatic D+/D− detection
setStatAsAnalogIB(enable, charging_only=false)	Configure STAT pin as analog IB or digital LED
getStatus(status)	Read all status/fault registers into PowerStatus struct
watchdogKick()	Reset the hardware watchdog timer
enterShippingMode()	Disconnect battery (deep power off)

PowerStatus Structure

The getStatus(PowerStatus &status) method populates the following fields:

Field	Type	Description
legacy_src_type	LegacyInputSrcType	Detected input source (USB SDP, DCP, CDP, etc.)
vin_good	bool	Input source is valid
charger_status	ChargerStatus	Charging state (Not Charging, Pre-charge, Fast Charge, Done, etc.)
charger_fault	ChargerFault	Fault type (None, Input OVP, Thermal Shutdown, Timer Expired, Battery OVP)
boost_fault	BoostFault	Boost mode fault (Overload, OVP, OTP, Battery Low)
fault_battery	bool	Battery missing or connection fault
fault_ntc	bool	NTC thermistor missing or fault
ntc1_state	NTCState	JEITA state for NTC1 (Normal, Warm, Cool, Cold, Hot)
cc1_snk_stat / cc2_snk_stat	CCSinkStatus	USB-C CC1/CC2 sink detection (vRa, vRd-USB, vRd-1.5A, vRd-3.0A)
cc1_src_stat / cc2_src_stat	CCSourceStatus	USB-C CC1/CC2 source detection (vOpen, vRd, vRa)
batt_low_stat	bool	Battery voltage is below low threshold
thermal_regulation	bool	IC is throttling charge current due to heat
input_dpm_regulation	bool	IC is throttling charge current due to input voltage/current limit (VINDPM)

Error Handling

All methods return MP2722_Result:

Code	Meaning
OK	Success
FAIL	I2C communication error
INVALID_ARG	Parameter out of range
INVALID_STATE	Operation not allowed (e.g., charging before configuring parameters)
TIMEOUT	I2C timeout
NOT_FOUND	Device not responding

License

Apache-2.0 license Copyright © 2026 Erik Gimenes dos Santos