How to Perform UART HILS Test

1. Overview

Using the SerialPort Class in System.IO.Ports Namespace, you can perform serial communication from the COM port of your computer.
The HILS test can be performed by replacing satellite components with simulated components in S2E.
This document describes how to perform HILS Test with UART components.
- If you want to perform HILS Test with I2C components, refer to here.

2. How to build files for the HILS test

Currently, the HILS test is only available for Visual Studio users on Windows.
Serial port operations are written in Interface/HilsInOut/Ports/HilsUartPort.cpp in c++/cli language.
When users want to execute the HILS test, complete the following steps.
- Edit s2e-core/CMakeLists.txt
  - option(USE_HILS "Use HILS" OFF) -> option(USE_HILS "Use HILS" ON)
- build s2e-core
Note: Currently, breakpoints do not work if you build c++/cli and c++ files simultaneously.

3. Sample codes for UART communication

The supported version of this document
- Please confirm that the version of the documents and s2e-core is compatible.
Hardware Settings
- Set loopback connection of two USB-UART converters using two USB ports of your computer.
- Check the COM port number for each connection.
- This tutorial assumes the use of USB-COMi-SI, a USB-UART converter.
Software Settings
- s2e-core/src/Component/Abstract/ExpHils.cpp is an example of a simulation component for serial port communication.
- ExpHils is instantiated in s2e-core/src/Simulation/Spacecraft/SampleComponents.cpp.
- Uncomment as follows in s2e-core/src/Simulation/Spacecraft/SampleComponents.cpp.
```
// UART tutorial. Comment out when not in use.
exp_hils_uart_responder_ = new ExpHils(clock_gen, 1, obc_, 3, 9600, hils_port_manager_, 1);
exp_hils_uart_sender_ = new ExpHils(clock_gen, 0, obc_, 4, 9600, hils_port_manager_, 0);
```
```
delete exp_hils_uart_responder_;
delete exp_hils_uart_sender_;
```
  - Edit the constructor's argument based on the COM port number checked above.
    - The fourth argument of ExpHils constructor is COM port number.
- Uncomment as follows in s2e-core/src/Simulation/Spacecraft/SampleComponents.h.
```
ExpHils* exp_hils_uart_responder_;
ExpHils* exp_hils_uart_sender_;
```
- For the HILS test, edit the setting of simulation speed in s2e-core/data/SampleSat/ini/SampleSimBase.ini.
```
// Simulation speed. 0: as fast as possible, 1: real-time, >1: faster than real-time, <1: slower than real-time
SimulationSpeed = 1
```
Execution and Result
- There are two ExpHils components, a sender component and a responder component.
  - The sender component sends out a new message like ABC, BCD, ....
  - The responder component returns the message as received.
  - Data returned from the responder to the sender is output to the console.
- If the comment Error: the specified step_sec is too small for this computer. appears, set StepTimeSec in SampleSimBase.ini to a larger value.