### Download and Install piSignage

Source: https://docs.pisignage.com/doc/setup/custom-hardware

Downloads the software package, sets necessary permissions, and runs the installation script.

```bash
wget https://pisignage.com/releases/pi-image-p2-v20.zip
```

```bash
unzip -o pi-image-p2-v20.zip
cp player2/build-scripts/install-pisignage.sh .
chmod +x install-pisignage.sh
chmod +x -R player2/build-scripts
chmod +x -R player2/shell-scripts
```

```bash
./install-pisignage.sh
```

```bash
sudo apt update --fix-missing
```

--------------------------------

### Configure SSH Server

Source: https://docs.pisignage.com/doc/setup/custom-hardware

Commands to install, enable, and start the SSH service for remote terminal access.

```bash
sudo apt install openssh-server        # Install the SSH server
sudo systemctl enable ssh              # Enable SSH service at boot
sudo systemctl start ssh               # Start the SSH service (or use sudo systemctl restart ssh if needed)
```

--------------------------------

### Verify and Install Chromium

Source: https://docs.pisignage.com/doc/setup/custom-hardware

Checks for existing Chromium installations and installs the browser if missing.

```bash
which chromium-browser
which chromium
# If neither is present, install using the following steps:
sudo apt-get -y install chromium-browser
# If 'chromium-browser' package is not found:
sudo apt-get -y install chromium
cd /usr/bin
sudo ln -s chromium chromium-browser
```

--------------------------------

### Compile and Run Signal Example

Source: https://docs.pisignage.com/doc/playlists

Commands to compile the C signal handler and execute it.

```bash
gcc sigusr2_example.c -o sigusr2_example
```

```bash
./sigusr2_example
```

--------------------------------

### Manual Software Upgrade

Source: https://docs.pisignage.com/doc/setup/custom-hardware

Steps to manually upgrade the piSignage software using a zip file.

```bash
1. Copy the pi-image-p2-v14.zip to home directory /home/pi
2. unzip -o pi-image-p2-v14.zip
3. chmod +x -R player2/shell-scripts
```

--------------------------------

### Upgrade OS Packages

Source: https://docs.pisignage.com/doc/setup/custom-hardware

Updates the package list and performs a full system upgrade.

```bash
sudo apt update
sudo apt full-upgrade -y
```

--------------------------------

### Verify Hostname Configuration

Source: https://docs.pisignage.com/doc/setup/custom-hardware

Checks the system hostname and ensures it is mapped in the hosts file.

```bash
hostname
cat hostname
otherwise add the same
127.0.0.1 <hostname>
```

--------------------------------

### Configure User Permissions

Source: https://docs.pisignage.com/doc/setup/custom-hardware

Commands to add a user to the sudo group and configure passwordless sudo access.

```bash
su -
usermod -aG sudo pi
```

```bash
sudo visudo and add the following as last line
<username, for e.g. pi> ALL=(ALL) NOPASSWD:ALL
```

--------------------------------

### Run and Signal Python Process

Source: https://docs.pisignage.com/doc/playlists

Commands to execute the Python script and send the SIGUSR2 signal using the kill command.

```bash
python3 signal_handler.py
```

```bash
kill -SIGUSR2 <PID>
# or using the signal number (SIGUSR2 is typically 12)
kill -12 <PID>
```

--------------------------------

### Handle SIGUSR2 Signals in C

Source: https://docs.pisignage.com/doc/playlists

Uses sigaction to catch and handle SIGUSR2 signals in a C program.

```c
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>


void signal_handler(int signum) {  
    if (signum == SIGUSR2) {  
        printf("\nReceived SIGUSR2 signal!\n");  
        printf("Performing some action...\n");  
    }  
}


int main() {  
    struct sigaction sa;

// Zero out the structure
memset(&sa, 0, sizeof(sa));

// Set the handler function
sa.sa_handler = signal_handler;

// Install the signal handler for SIGUSR2
if (sigaction(SIGUSR2, &sa, NULL) == -1) {
    perror("sigaction");
    return 1;
}

printf("My PID is: %d\n", getpid());
printf("Waiting for SIGUSR2...\n");

// Keep the program running
while (1) {
    sleep(1);
}

return 0;
```

--------------------------------

### Handle SIGUSR2 in Python

Source: https://docs.pisignage.com/doc/playlists

Registers a signal handler for SIGUSR2 to perform custom actions when the signal is received.

```python
import os
import signal
import time


# Define the signal handler function


def receive_sigusr2(signal_number, frame):  
    print(f"\nReceived signal: {signal_number} (SIGUSR2)")  
    print("Performing custom action (e.g., reloading config, toggling a GPIO pin)...")


# Register the SIGUSR2 signal handler


signal.signal(signal.SIGUSR2, receive_sigusr2)


print(f"My PID is: {os.getpid()}")  
print("Waiting for SIGUSR2... (Press Ctrl+C to exit)")


# Keep the program running indefinitely


while True:  
    time.sleep(1)  
```