Servo 2 Click

How does it work?

Servo 2 Click is based on the TLC59401, a 16-channel LED driver from Texas Instruments designed to control multiple outputs using a high-precision constant-current sink architecture. Each of the 16 channels features an individually programmable 12-bit grayscale PWM control, allowing for 4096 levels of pulse width adjustment per output. This level of control is accessible via a serial interface, ensuring flexible and accurate operation across all channels. The maximum output current for each channel is defined by a single external resistor, which simplifies configuration. On the Servo 2 Click, this resistor is set to 330Ω (R7), resulting in a maximum current of approximately 120mA per channel. This makes the board well-suited not only for precise servo motor control but also for driving high-current LEDs in secondary applications, including monocolor, multicolor, and full-color LED displays, signboards, and back-lighting systems where accurate brightness control and current regulation are essential.

This Click board™ establishes communication with the host MCU via a 4-wire SPI interface with a maximum clock frequency of 30MHz, ensuring reliable and high-speed data transfer. Beyond the SPI pins, the board includes additional control and status lines that enhance its functionality. The BLK pin is used to blank all outputs simultaneously – when set HIGH, all output channels are disabled and the internal grayscale counter is reset. When driven LOW, the outputs resume operation under the control of the internal PWM grayscale engine. The design also supports the parallel configuration of multiple output channels to increase total current-driving capability.

The supply voltage for the connected loads is provided through the VEXT terminal, which distributes the same voltage to all output channels. This voltage can go up to a maximum of 17V, making the board compatible with a wide range of connected devices, including servo motors and LEDs. Additionally, the ERR pin provides essential fault indication through two integrated monitoring features: LED open detection (LOD), which flags disconnected or broken LEDs, and the thermal error flag (TEF), which signals an over-temperature condition.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC 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.

Specifications

Pinout diagram

This table shows how the pinout on Servo 2 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Output Channel Control	BLK	1	AN	PWM	16	GSC	Grayscale PWM control
ID SEL	RST	2	RST	INT	15	ERR	Error Detection
SPI Select / ID COMM	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Servo 2 Click electrical specifications

Software Support

Servo 2 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 Servo 2 Click board for controlling the angle of servo motors. The board is capable of driving multiple servos, and the example illustrates how to change the angle of all connected servos simultaneously within a defined range.

Key Functions

• servo2_cfg_setup Config Object Initialization function.
• servo2_init Initialization function.
• servo2_set_angle This function sets the servo angle for a specific channel or all channels.
• servo2_update_output This function updates the PWM output values for all channels by writing them to the device.
• servo2_set_channel_pwm This function sets the PWM output for a specific channel or all channels.

Application Init

Initializes the logger module and configures the Servo 2 Click board. The PWM communication is established, and the device is prepared for controlling the servos.

Application Task

Gradually changes the angle of all connected servo motors from a minimum to a maximum value, and then back to the minimum, creating a sweeping motion. The current angle is logged during each update.

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.