Checking Communication and Reading Device Information
This tutorial shows how to verify communication with a PULSAR HRI actuator before running motion-control examples. It covers how to connect through a known serial port, check whether the adapter is available, connect to the actuator, identify it with the LED blink function, and read the full parameter set.
Requirements
Before running the example, make sure:
- the C++ API is built,
- the actuator is connected and reachable,
- the user has permission to access the communication device,
- the serial port is known and available.
Include files
The following headers are required for this example:
Connect to a known serial port
This example uses a fixed serial port instead of automatic port detection. Replace the port string with the device path used on your system.
const std::string port = "/dev/ttyACM0"; // Replace with your device port
PCP_over_USB adapter(port);
The example below uses a Linux-style device path. On other systems, the port name may look different.
Check that the adapter is connected
Use is_connected() to verify that the adapter is available before trying to communicate with the actuator.
if (!adapter.is_connected()) {
std::cerr << "Adapter not connected on port " << port << std::endl;
adapter.close();
throw std::runtime_error("Adapter connection failed");
}
Connect to the actuator
Create the actuator instance and connect to it. When connecting directly through USB, use address 0. If you are using CAN, replace it with the correct actuator PCP address.
constexpr int ACTUATOR_ADDRESS = 0;
PulsarActuator actuator(adapter, ACTUATOR_ADDRESS);
if (!actuator.connect()) {
std::cerr << "Actuator not responding at address "
<< ACTUATOR_ADDRESS << std::endl;
adapter.close();
throw std::runtime_error("Actuator connection failed");
}
std::cout << "Connected to actuator " << actuator.address()
<< " (model: " << actuator.model()
<< ", firmware: " << actuator.firmware_version()
<< ")"
<< std::endl;
Identify the actuator with the LED blink function
Use blink() to flash the actuator LED and confirm that you are communicating with the expected device.
Read the full parameter set
Use get_parameters_all() to retrieve the full set of parameters from the actuator.
auto params = actuator.get_parameters_all();
std::cout << "Read " << params.size() << " parameters" << std::endl;
This is useful for diagnostics, configuration inspection, and confirming that the actuator is responding correctly.
Disconnect and clean up
Disconnect the actuator and close the adapter when the check is finished.
Complete example
The following program is a complete example that can be copied into a .cpp file and compiled directly.
#include <pcp_api/pcp_api.hpp>
#include <iostream>
#include <stdexcept>
#include <string>
using namespace pcp_api;
int main()
{
PCP_over_USB* adapter_ptr = nullptr;
try {
constexpr int ACTUATOR_ADDRESS = 0;
const std::string port = "/dev/ttyACM0"; // Replace with your device port
PCP_over_USB adapter(port);
adapter_ptr = &adapter;
if (!adapter.is_connected()) {
std::cerr << "Adapter not connected on port " << port << std::endl;
adapter.close();
return 1;
}
PulsarActuator actuator(adapter, ACTUATOR_ADDRESS);
if (!actuator.connect()) {
std::cerr << "Actuator not responding at address "
<< ACTUATOR_ADDRESS << std::endl;
adapter.close();
return 1;
}
std::cout << "Connected to actuator " << actuator.address()
<< " (model: " << actuator.model()
<< ", firmware: " << actuator.firmware_version()
<< ")"
<< std::endl;
actuator.blink();
auto params = actuator.get_parameters_all();
std::cout << "Read " << params.size() << " parameters" << std::endl;
actuator.disconnect();
adapter.close();
}
catch (const std::exception& e) {
if (adapter_ptr != nullptr) {
try {
adapter_ptr->close();
} catch (...) {
}
}
std::cerr << "Fatal error: " << e.what() << std::endl;
return 1;
}
return 0;
}
Example build command
Adjust the include path, library path, and library names to match your build output.