Digital Out

Hardware

The AutomatePro comes with 12x digital outputs for controlling external systems from small solenoids to LEDs or small DC motors. There are two different digital outputs available, one is setup as a highside output (DO_H_0x) which PWMs the onboard 12V as an output. The second is a Lowside sink (DO_L_0x) which sinks upto 36V with the first four being PWM controllable and

Connector Pinout

Connector

Development Breakout Board

Digital Output Highside (DO_H_x) Specifications

There are 6x highside digital outputs with all 6 being PWM controllable switches.

Parameter	Value
Output Voltage (Onstate)	+12V (from on-board 12V)
Drive Current	500mA
PWM Controllable	All (DO_H_01 - DO_H_06)
PWM Switching Frequency	500Hz
Number of Outputs	6

Digital Output Lowside (DO_L_x) Specifications

There are 6x lowside digital outputs the first four are PWM controllable while the final two are binary on/off switches.

Parameter	Value
Onstate	Sinks up to 36V
Drive Current	500mA
PWM Controllable	DO_L_01 DO_L_02 DO_L_03 DO_L_04 D0_L_05 & DO_L_06 are On/Off switches
PWM Switching Frequency	10Hz
Number of Inputs	6

ROS API

Subscribers

Topic	Type	Description
/io/digital_out	automatepro_interfaces/msg/DigitalOut	Publish the desired digital out states to this topic. AutomatePro supports 12 digital out pins (6 High Side and 6 Low Side). Each input pin is referred to as DIGITAL_OUT_H_XX or DIGITAL_OUT_L_XX, where H/L refer to High Side/Low Side, XX is the pin number, ranging from 01 to 06. d_out_pin_id: DataType: uint8 (Use ENUM constants defined in msg definiton. DigitalOut.DIGITAL_OUT_H_XX: 01-06 DigitalOut.DIGITAL_OUT_L_XX: 01-06) duty_cycle_percent: DataType: uint8 Min: 0 in percentage % Max: 100 in percentage % Response Rate: 200 ms

Example

Example code snippets toggles the duty cycle of Digital Out 01 by publishing to the /io/digital_out topic.

Python

import rclpy
from rclpy.node import Node
from automatepro_interfaces.msg import DigitalOut

class DigitalOutPublisher(Node):

    def __init__(self):
        super().__init__('digital_out_publisher')
        self.publisher_ = self.create_publisher(DigitalOut, '/io/digital_out', 10)
        self.timer = self.create_timer(1.0, self.timer_callback)  # 1s
        self.duty_cycle_sequence = [0, 50, 100, 50]
        self.sequence_index = 0

    def timer_callback(self):
        msg = DigitalOut()
        msg.d_out_pin_id = DigitalOut.DIGITAL_OUT_H_01 # Digital Out High Side Pin 01
        msg.duty_cycle_percent = self.duty_cycle_sequence[self.sequence_index] # Duty Cycle:  0%, 50%, 100%, 50%
                                                                               # 0% - OFF, 100% - ON 
        self.publisher_.publish(msg)
        self.get_logger().info('Publishing: "%s"' % msg)
        self.sequence_index = (self.sequence_index + 1) % len(self.duty_cycle_sequence)

def main(args=None):
    rclpy.init(args=args)
    node = DigitalOutPublisher()
    rclpy.spin(node)
    node.destroy_node()
    rclpy.shutdown()

if __name__ == '__main__':
    main()

Run the node using the following command:

ros2 run automatepro_python_tutorials digital_out_node

C++

#include <vector>
#include <rclcpp/rclcpp.hpp>
#include <automatepro_interfaces/msg/digital_out.hpp>

class DigitalOutPublisher : public rclcpp::Node
{
public:
    DigitalOutPublisher()
        : Node("digital_out_publisher"),
          duty_cycle_sequence_{0, 50, 100, 50},
          sequence_index_(0)
    {
        publisher_ = this->create_publisher<automatepro_interfaces::msg::DigitalOut>("/io/digital_out", 10);
        timer_ = this->create_wall_timer(
            std::chrono::seconds(1),
            std::bind(&DigitalOutPublisher::timer_callback, this));
    }

private:
    void timer_callback()
    {
        auto msg = automatepro_interfaces::msg::DigitalOut();
        msg.d_out_pin_id = automatepro_interfaces::msg::DigitalOut::DIGITAL_OUT_H_01; // Digital Out High Side Pin 01
        msg.duty_cycle_percent = duty_cycle_sequence_[sequence_index_]; // Duty Cycle: 0%, 50%, 100%, 50%
                                                                        // 0% - OFF, 100% - ON
        publisher_->publish(msg);
        RCLCPP_INFO(this->get_logger(), "Publishing: d_out_pin_id=%d, duty_cycle_percent=%d", msg.d_out_pin_id, msg.duty_cycle_percent);

        // Update the sequence index
        sequence_index_ = (sequence_index_ + 1) % duty_cycle_sequence_.size();
    }

    rclcpp::Publisher<automatepro_interfaces::msg::DigitalOut>::SharedPtr publisher_;
    rclcpp::TimerBase::SharedPtr timer_;
    std::vector<int> duty_cycle_sequence_;
    size_t sequence_index_;
};

int main(int argc, char *argv[])
{
    rclcpp::init(argc, argv);
    rclcpp::spin(std::make_shared<DigitalOutPublisher>());
    rclcpp::shutdown();
    return 0;
}

Run the node using the following command:

ros2 run automatepro_cpp_tutorials digital_out_node