Introduction
Programs created with MATRIX HAL allow you to directly access sensors and components on the MATRIX device through C++. This guide will show you how to create and run an LED demo in MATRIX HAL. The final result being a rainbow LED sequence.
Creating A Program
Making Your Project Directory
Use the following commands to create a folder to hold your MATRIX HAL projects, in the home directory ~/ of your MATRIX device.
cd ~/ mkdir matrix-hal-project cd matrix-hal-project
Create a file called app.cpp in your project folder, and paste the code below.
The following code turns the Everloop rainbow for 10 seconds.
/* * Everloop rainbow example */ ///////////////////////// // INCLUDE STATEMENTS // /////////////////////// // System calls #include <unistd.h> // Input/output streams and functions #include <iostream> // Included for sin() function. #include <cmath> // Interfaces with Everloop #include "matrix_hal/everloop.h" // Holds data for Everloop #include "matrix_hal/everloop_image.h" // Communicates with MATRIX device #include "matrix_hal/matrixio_bus.h" int main() { //////////////////// // INITIAL SETUP // ////////////////// // Create MatrixIOBus object for hardware communication matrix_hal::MatrixIOBus bus; // Initialize bus and exit program if error occurs if (!bus.Init()) return false; ///////////////// // MAIN SETUP // /////////////// // Holds the number of LEDs on MATRIX device int ledCount = bus.MatrixLeds(); // Create EverloopImage object, with size of ledCount matrix_hal::EverloopImage everloop_image(ledCount); // Create Everloop object matrix_hal::Everloop everloop; // Set everloop to use MatrixIOBus bus everloop.Setup(&bus); // Variables used for sine wave rainbow logic float counter = 0; const float freq = 0.375; // 10 sec loop for rainbow effect 250*40000 microsec = 10 sec for (int i = 0; i <= 250; i++) { // For each led in everloop_image.leds, set led value for (matrix_hal::LedValue &led : everloop_image.leds) { // Sine waves 120 degrees out of phase for rainbow led.red = (std::sin(freq * counter + (M_PI / 180 * 240)) * 155 + 100) / 10; led.green = (std::sin(freq * counter + (M_PI / 180 * 120)) * 155 + 100) / 10; led.blue = (std::sin(freq * counter + 0) * 155 + 100) / 10; // If MATRIX Creator, increment by 0.51 if (ledCount == 35) { counter = counter + 0.51; } // If MATRIX Voice, increment by 1.01 if (ledCount == 18) { counter = counter + 1.01; } } // Updates the LEDs everloop.Write(&everloop_image); // If i is 0 (first run) if (i == 0) { // Output everloop status to console std::cout << "Everloop set to rainbow for 10 seconds." << std::endl; } // If i is cleanly divisible by 25 if ((i % 25) == 0) { std::cout << "Time remaining (s) : " << 10 - (i / 25) << std::endl; } // Sleep for 40000 microseconds usleep(40000); } // Updates the Everloop on the MATRIX device everloop.Write(&everloop_image); // For each led in everloop_image.leds, set led value to 0 for (matrix_hal::LedValue &led : everloop_image.leds) { // Turn off Everloop led.red = 0; led.green = 0; led.blue = 0; led.white = 0; } // Updates the Everloop on the MATRIX device everloop.Write(&everloop_image); return 0; }
Compiling your Program
The command below will use g++ to link the libmatrix_creator_hal.so library file when compiling your program.
g++ -o app app.cpp -std=c++11 -lmatrix_creator_hal
Running your Program
Run the following command to start the demo program.
cd ~/matrix-hal-project
./app
Result
Next Steps
Now that everything is properly installed, view our function references to see what you can do with MATRIX HAL, or view the code examples.