How Does The DC Motor 25 Click Board™ Work?
The DC Motor 25 Click Board™ is based on the A3908, a fully integrated low-voltage motor driver for DC motors from Allegro Microsystems. This Click board™ provides all the input and output capabilities necessary to drive DC motors (OUT terminal), alongside monitor diagnostic functions. The A3908 is rated for an operating voltage range compatible with both mikroBUS™ power rails and output currents up to 500mA, programmable via an external I2C-configurable digital potentiometer, the AD5171 from Analog Devices. The A3908 also has complete protection capabilities like thermal shutdown, undervoltage lockout, and crossover current (shoot-through) protection, allowing robust and reliable operation.
Logic pins labelled IN1 and IN2, routed on the default positions of RST and PWM pins of the mikroBUS socket, are provided to control the motor direction of rotation, brake, and standby modes. When both pins are in a high logic state, the A3908 goes into high-side brake mode, which turns on both source drivers. There is no protection during braking, so care must be taken to ensure that the peak current does not exceed the absolute maximum current.
Th DC Motor 25 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. However, the 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
| Type | Brushed |
| Applications | It can be used for robotic actuators and pumps, battery-powered toys and games, low-noise instrumentation systems, and more |
| On-board modules | A3908 - bidirectional DC motor driver from Allegro Microsystems |
| Key Features | Adjustable output current up to 500mA, driver control via logic pins, additional operational modes, internal protection, wide operating voltage range, low power consumption, and more |
| Interface | GPIO, I2C |
| Compatibility | mikroBUS |
| Click board size | S (28.6 x 25.4 mm) |
| Input Voltage | 3.3V or 5V |
PINOUT DIAGRAM
This table shows how the DC Motor 25 Click Board™ pinout 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 | IN2 | Driver Control 2 | |
| Driver Control 1 | IN1 | 2 | RST | INT | 15 | NC | |
| NC | 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
| Label | Name | Default | Description |
|---|---|---|---|
| LD1 | PWR | - | Power LED Indicator |
| JP1 | VCC SEL | Left | Power Voltage Level Selection 3V3/5V: Left position 3V3, Right position 5V |
DC MOTOR 25 CLICK ELECTRICAL SPECIFICATIONS
| Description | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage | 3.3 | - | 5 | V |
| Output Current | - | - | 500 | mA |