Charger 29 Click

How does it work?

Charger 29 Click is based on the BQ25188, a highly integrated linear battery charger from Texas Instruments, optimized for extending battery life through its ultra-low quiescent current operation. This board is made for single-cell battery charging and power path management in low-power, space-constrained applications. It supports fast charging currents configurable from 5mA to 1A, making it suitable for various battery chemistries including Li-ion, Li-Polymer, and LiFePO4. The board allows a system load of up to 3A, thanks to the 55mΩ ON-resistance battery FET and advanced power path control, ensuring easy supply switching between input and battery sources.

Charger 29 Click is capable of operating from a wide input voltage range of 3V to 18V via the VEXT header, allowing battery-to-battery charging scenarios, while also supporting 5V input from the mikroBUS™ power rail. Input power source selection is easily managed using the VIN SEL jumper. The charger provides a regulated system output on the SYS header, adjustable from 4.4V to 5.5V, and also supports battery voltage tracking. The BQ25188 integrates intelligent battery temperature monitoring via the TS pin with configurable NTC thresholds, including full JEITA compliance, to ensure safe charging in wearable and portable devices.

Moreover, the board includes comprehensive protection mechanisms such as input overvoltage, battery short and overcurrent protection, thermal regulation and shutdown, and battery thermal fault detection. Its battery regulation voltage can be finely tuned with 0.5% accuracy in 10mV steps across a 3.6V to 4.65V range. Charger 29 Click is a highly adaptable and reliable power management solution, ideal for use in smart wearables, TWS headsets and charging cases, AR/VR glasses, retail automation systems, and building automation applications.

This Click board™ is designed in a unique format supporting the newly introduced MIKROE feature called "Click Snap." Unlike the standardized version of Click boards, this feature allows the main sensor/IC/module area to become movable by breaking the PCB, opening up many new possibilities for implementation. Thanks to the Snap feature, the BQ25188 can operate autonomously by accessing its signals directly on the pins marked 1-8. Additionally, the Snap part includes a specified and fixed screw hole position, enabling users to secure the Snap board in their desired location.

This Click board™ uses an I2C interface with clock speeds of up to 400kHz, ensuring fast communication with the host MCU. Beyond communication pins, this board is also equipped with an interrupt (INT) pin that signals fault interrupts, and a MR button to send interrupts to the host MCU as a button is pressed or to allow the application end user to reset the system.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VIO SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

Click Snap

Click Snap is an innovative feature of our standardized Click add-on boards, designed to bring greater flexibility and optimize your prototypes. By simply snapping the PCB along predefined lines, you can easily detach the main sensor/IC/module area, reducing the overall size, weight, and power consumption - ideal for the final phase of prototyping. For more details about Click Snap, visit the official page dedicated to this feature.

Specifications

Pinout diagram

This table shows how the pinout on Charger 29 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
	NC	2	RST	INT	15	INT	Interrupt
ID COMM	CS	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Charger 29 Click electrical specifications

Software Support

Charger 29 Click demo application is developed using the NECTO Studio, ensuring compatibility with mikroSDK's open-source libraries and tools. Designed for plug-and-play implementation and testing, the demo is fully compatible with all development, starter, and mikromedia boards featuring a mikroBUS™ socket.

Example Description

This example demonstrates the use of the Charger 29 Click board. The application initializes the device and periodically checks the charging status. The status is displayed over the UART terminal and reflects whether the battery is charging in constant current (CC) mode, constant voltage (CV) mode, fully charged, or not charging.

Key Functions

• charger29_cfg_setup This function initializes Click configuration structure to initial values.
• charger29_init This function initializes all necessary pins and peripherals used for this Click board.
• charger29_default_cfg This function executes a default configuration of Charger 29 Click board.
• charger29_enable_charging This function enables charging by clearing the charging disable bit.
• charger29_set_charging_current This function sets the charging current based on the specified value in milliamps.
• charger29_read_status This function reads the status and flag registers of the Charger 29 Click board.

Application Init

Initializes the logger and the Charger 29 Click driver and applies default configuration.

Application Task

Periodically reads and logs the charging status once per second.

Application Output

This Click board can be interfaced and monitored in two ways:

• Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
• UART Terminal - Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.

Additional Notes and Information

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.