Elderly MP4 Player — Complete Build Guide

Raspberry Pi 4 + ESP32 Wireless Remote

0.1 Purpose

This guide walks you through building a simple, reliable MP4 video player designed for a senior (90+ years old) who needs the simplest possible experience:

• No menus. No remote to lose. No confusing interfaces.
• Press one button — something happens immediately.
• Large, color-coded physical buttons they can find by touch.
• Videos play automatically on the TV. YouTube favorites load with one red button.

The system has two physical pieces:

Piece	What it does	Where it lives
Raspberry Pi 4 box	Plays videos, runs the software, connects to the TV	Hidden behind the TV
ESP32 wireless remote	6 large buttons, battery powered, no wires	On the senior’s side table or armrest

Overall progress

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1 Part 1 — Raspberry Pi Box

Pi 4 Build — mounts behind TV

This section sets up the Pi, installs the software, wires the buttons, and mounts everything in the box.

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1.1 Step 1 — Prepare the microSD OS card

Parts needed: Pi 4 board, 32GB microSD card (item 4), your laptop or desktop PC

1.1.1 Tasks

• Download Raspberry Pi Imager from raspberrypi.com/software and install it on your laptop.
• Insert the 32GB microSD into your laptop’s card reader (or a USB adapter).
• Open Raspberry Pi Imager. Click Choose OS → Raspberry Pi OS (64-bit).
• Click Choose Storage → select your 32GB card.
• Click the gear icon (Advanced Options) before writing:
  • Set hostname: mpvplayer
  • Enable SSH: checked
  • Set username: pi and a password you will remember
  • Configure WiFi: enter your home WiFi name and password
  • Set locale / timezone to your region
• Click Write and wait for it to finish (~5 minutes).
• Remove the microSD card from your laptop safely.

TEST 1.1 — Card written correctly

• Insert the card back into your laptop after writing.
• You should see a drive called bootfs appear in Windows Explorer or Finder.
• If the drive appears, the card is ready. If Windows asks to format it, something went wrong — repeat the write.

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1.2 Step 2 — Assemble the Pi in its case

Parts needed: Pi 4 board (item 1), Pi case with fan (item 3), heatsinks (included with case), 32GB microSD

1.2.1 Tasks

• Peel the backing off the heatsinks and stick them onto the Pi’s chips (the case instructions show which chips — usually 3 heatsinks total).
• Seat the Pi board into the bottom half of the case — it clicks in.
• Connect the small fan connector to the Pi’s fan header pins (usually labeled FAN on the board, or GPIO pins 4 and 6).
• Snap the top of the case on.
• Insert the 32GB microSD card into the slot on the underside of the Pi (small slot, gold contacts face down, slides in with a gentle click).

TEST 2.1 — Physical assembly

• Gently press each heatsink — they should not slide.
• The microSD card should be seated flush — it should not wiggle.
• The case lid should close flat with no gaps.

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1.3 Step 3 — First boot and SSH connection

Parts needed: Pi in case, power supply (item 2), micro-HDMI cable (item 7), TV, your laptop on the same WiFi

1.3.1 Tasks

• Connect the micro-HDMI cable from the Pi’s HDMI0 port (the one closest to the USB-C power port) to your TV.
• Switch the TV input to the correct HDMI port.
• Plug the USB-C power supply into the Pi and into the wall.
• Watch the TV — you should see a rainbow screen briefly, then a desktop or terminal boot sequence.
• Wait ~60 seconds for the first boot to complete.
• On your laptop, open a terminal (Windows: PowerShell or Windows Terminal; Mac: Terminal).
• Type the following and press Enter:

ssh pi@mpvplayer.local

• Type yes when asked about fingerprint, then enter your password.
• You should see a prompt like pi@mpvplayer:~ $ — you are now connected.

TEST 3.1 — SSH works

At the SSH prompt, type:

hostname

Expected output: mpvplayer

Type:

ping -c 3 google.com

Expected output: 3 lines showing ping replies. This confirms WiFi and internet are working.

If SSH fails: Make sure your laptop is on the same WiFi network as the Pi. Try ssh pi@192.168.x.x using the Pi’s IP address instead (find it in your router’s connected devices list).

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1.4 Step 4 — Install software on the Pi

Parts needed: SSH connection from Step 3

1.4.1 Tasks

Run each command below one at a time in your SSH terminal. Wait for each to finish before running the next.

• Update the system:

sudo apt update && sudo apt upgrade -y

• Install mpv video player:

sudo apt install mpv -y

• Install Python Flask (for the remote server):

pip install flask --break-system-packages

• Install the GPIO library:

sudo apt install python3-rpi.gpio -y

• Set up the project folder structure:

mkdir -p ~/mp4player/A-Data/videos
mkdir -p ~/mp4player/B-Engines
mkdir -p ~/mp4player/C-Results
touch ~/mp4player/A-Data/youtube.txt

• Copy a test MP4 file to the Pi to verify playback works (from your laptop, in a separate terminal window):

scp /path/to/your/test-video.mp4 pi@mpvplayer.local:/home/pi/mp4player/A-Data/videos/

TEST 4.1 — mpv plays video on the TV

In your SSH session, run:

mpv --fs /home/pi/mp4player/A-Data/videos/test-video.mp4

Expected: video plays fullscreen on the TV. Press q to quit.

TEST 4.2 — Flask installed

python3 -c "import flask; print('Flask OK:', flask.__version__)"

Expected output: Flask OK: followed by a version number.

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1.5 Step 5 — Copy the Python scripts to the Pi

Parts needed: SSH connection, the two Python files from this project (remote_server.py)

1.5.1 Tasks

• From your laptop terminal, copy remote_server.py to the Pi:

scp remote_server.py pi@mpvplayer.local:/home/pi/mp4player/B-Engines/

• Back in your SSH session, test-run the server manually:

cd ~/mp4player/B-Engines
python3 remote_server.py

• Leave it running and open a browser on your laptop or phone.
• In the browser address bar, type (replace IP with your Pi’s IP):

http://mpvplayer.local:5000/cmd/play

• Confirm the video starts playing on the TV.
• Test each command URL in the browser:
  • http://mpvplayer.local:5000/cmd/next
  • http://mpvplayer.local:5000/cmd/prev
  • http://mpvplayer.local:5000/cmd/volup
  • http://mpvplayer.local:5000/cmd/voldown
• Press Ctrl+C in the SSH terminal to stop the test run.

TEST 5.1 — Each command works via browser

Each URL in the browser should return a small JSON response like:

{"paused": false, "status": "ok", "volume": 70}

And you should see/hear the corresponding action on the TV.

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1.6 Step 6 — Set up auto-start on boot

Parts needed: SSH connection

1.6.1 Tasks

• In your SSH session, create a systemd service file:

sudo nano /etc/systemd/system/mp4player.service

• Paste the following content exactly (use Ctrl+Shift+V to paste in the terminal):

[Unit]
Description=Elderly MP4 Player Server
After=network.target

[Service]
User=pi
WorkingDirectory=/home/pi/mp4player/B-Engines
ExecStart=/usr/bin/python3 /home/pi/mp4player/B-Engines/remote_server.py
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target

• Press Ctrl+X, then Y, then Enter to save and exit.
• Enable and start the service:

sudo systemctl daemon-reload
sudo systemctl enable mp4player.service
sudo systemctl start mp4player.service

• Check that the service is running:

sudo systemctl status mp4player.service

• Reboot the Pi to confirm it auto-starts:

sudo reboot

• Wait 60 seconds, then test in your browser:

http://mpvplayer.local:5000/

TEST 6.1 — Auto-start after reboot

After rebooting, open browser and go to:

http://mpvplayer.local:5000/

Expected: a simple page saying “MP4 Player Remote Server”. This confirms the server started automatically without you doing anything.

TEST 6.2 — Video plays on boot

If you have a video in A-Data/videos/, it should start playing on the TV automatically within ~30 seconds of powering on the Pi with no keyboard or mouse needed.

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1.7 Step 7 — Wire the 6 buttons to the Pi

Parts needed: 6 arcade buttons (items 8–11), female-to-female Dupont wires (item 13), Pi in case

1.7.1 GPIO wiring reference

Button	Color	Pi GPIO pin (BCM)	Also connect to
Play / Pause	GREEN	GPIO 17 (pin 11)	GND (pin 9)
Previous	BLUE	GPIO 27 (pin 13)	GND (pin 14)
Next	BLUE	GPIO 22 (pin 15)	GND (pin 20)
Vol Down	WHITE	GPIO 23 (pin 16)	GND (pin 25)
Vol Up	WHITE	GPIO 24 (pin 18)	GND (pin 20)
YouTube	RED	GPIO 25 (pin 22)	GND (pin 25)

Important: Each button has two terminals on the microswitch (the small black box clipped to the button). One terminal gets the GPIO wire, the other gets a GND wire. The orientation does not matter — either terminal can be either wire.

1.7.2 Tasks

• Before drilling, lay all 6 buttons on top of the box lid and mark hole positions in pencil — center the large green button, blue buttons left and right of it, white volume buttons below, red button off to one side with a gap.
• Drill 2.4 in (approx) holes at each marked position using the step drill bit. Drill slowly.
• Push each button through its hole from above and tighten the plastic ring nut from below (finger tight).
• For each button: push one Dupont female end onto one terminal, another Dupont female end onto the other terminal. Label or note which is signal vs GND.
• Route all wires out the back of the box through a small notch or hole.
• Connect each GPIO Dupont wire to the correct Pi GPIO pin as per the table above.
• Connect each GND Dupont wire to any GND pin on the Pi header.

TEST 7.1 — Each button triggers the correct action

With the Pi running, press each button one at a time and watch the TV:

• Green → video pauses / resumes
• Left Blue → goes to previous video
• Right Blue → goes to next video
• White (left) → volume decreases
• White (right) → volume increases
• Red → YouTube playlist starts

Check the log file to confirm button presses are registered:

ls ~/mp4player/C-Results/
cat ~/mp4player/C-Results/remote-server-*.txt | tail -20

You should see [DEBUG] Received command: lines for each button press.

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1.8 Step 8 — Mount Pi box behind the TV

Parts needed: Pi in assembled box, micro-HDMI cable, power supply, USB SD card reader (item 6), 128GB media microSD (item 5)

1.8.1 Tasks

• Stick 4 rubber feet to the bottom of the Pi case.
• Insert the 128GB media microSD into the USB SD card reader.
• Plug the USB SD card reader into one of the Pi’s USB ports.
• Connect the micro-HDMI cable to the Pi (HDMI0 port) and to the TV.
• Position the Pi box behind the TV — cable tie or velcro it to the TV stand or VESA mount if possible.
• Plug the power supply into the Pi and a nearby wall outlet.
• Copy your MP4 video files onto the 128GB media card. The simplest way is to put the media card in your laptop first, copy all files into a folder called videos, then put it back in the USB reader.
• Update remote_server.py so VIDEO_DIR points to the USB card mount path:

# Find the mount path of the USB card reader
lsblk
# It is usually something like /media/pi/YOURCARD/videos
# Update VIDEO_DIR in remote_server.py accordingly

TEST 8.1 — Full system test from power-on

1. Power off the Pi completely (unplug power).
2. Wait 10 seconds.
3. Plug power back in.
4. Watch the TV — within 60 seconds, the first video should start playing automatically.
5. No keyboard, no mouse, no login prompt — just video.

This is the final Pi build test. If this passes, the Pi box is complete.

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2 Part 2 — ESP32 Wireless Remote

ESP32 Build — handheld wireless remote

This section installs the Arduino IDE, programs the ESP32, wires the buttons, and assembles the handheld remote box.

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2.1 Step 9 — Install Arduino IDE on your laptop

Parts needed: Your laptop, USB-A to USB-C cable (item 24)

2.1.1 Tasks

• Download Arduino IDE 2.x from arduino.cc/en/software and install it.
• Open Arduino IDE.
• Go to File → Preferences.
• In the Additional boards manager URLs field, paste this URL:

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

• Click OK.
• Go to Tools → Board → Boards Manager.
• Search for esp32 and install esp32 by Espressif Systems (version 2.x or later). This takes ~2–3 minutes.
• Once installed, go to Tools → Board → ESP32 Arduino → ESP32 Dev Module.

TEST 9.1 — Board installed correctly

Go to Tools → Board — you should see “ESP32 Dev Module” listed and selected with a checkmark.

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2.2 Step 10 — Edit and upload the ESP32 sketch

Parts needed: ESP32 board, USB-A to USB-C cable (item 24), laptop with Arduino IDE

2.2.1 Tasks

• Open esp32_remote.ino in Arduino IDE (File → Open → browse to the file).
• Find the three lines marked EDIT near the top and fill them in:

const char* WIFI_SSID     = "YourWiFiName";      // your home WiFi network name
const char* WIFI_PASSWORD = "YourWiFiPassword";  // your home WiFi password
const char* PI_IP         = "192.168.x.x";       // your Pi's local IP address

Finding your Pi’s IP address: In your SSH session on the Pi, type hostname -I — it will show something like 192.168.1.50. Use that number.

• Connect the ESP32 to your laptop using the USB-C cable.
• In Arduino IDE go to Tools → Port and select the COM port that appeared when you plugged in the ESP32 (on Windows: COM3, COM4, etc.; on Mac: /dev/cu.usbserial-…).
• Click the Upload button (right-pointing arrow) and wait for “Done uploading” message (~30 seconds).
• Open Tools → Serial Monitor, set baud rate to 115200.
• Press the EN/Reset button on the ESP32 board.

TEST 10.1 — ESP32 connects to WiFi

In the Serial Monitor you should see:

[DEBUG] ESP32 Remote booting...
[DEBUG] Connecting to WiFi: YourWiFiName
.....
[DEBUG] Connected! ESP32 IP: 192.168.x.x

And the small LED on the ESP32 board should blink 3 times.

If you see dots continuing for more than 20 seconds without connecting, double-check the WiFi name and password (they are case-sensitive).

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2.3 Step 11 — Wire the 6 buttons to the ESP32

Parts needed: 6 arcade buttons (item 15), Dupont wires, ESP32 board, breadboard (item 23) for testing first

2.3.1 ESP32 button wiring reference

Button	Color	ESP32 GPIO pin	Also connect to
Play / Pause	GREEN	GPIO 13	GND
Previous	BLUE	GPIO 12	GND
Next	BLUE	GPIO 14	GND
Vol Down	WHITE	GPIO 27	GND
Vol Up	WHITE	GPIO 26	GND
YouTube	RED	GPIO 25	GND

Test on the breadboard first before putting anything in the box. Wire all 6 buttons on the breadboard, confirm each one works, then transfer to the final box.

2.3.2 Tasks

• Breadboard test first: wire all 6 buttons to the ESP32 on the breadboard using Dupont wires per the table above.
• Keep the ESP32 connected to your laptop via USB and open Serial Monitor.
• Press each button one by one and confirm the Serial Monitor shows the correct command being sent:

[DEBUG] Button: PLAY/PAUSE (GPIO 13)
[DEBUG] Sending: http://192.168.x.x:5000/cmd/play
[DEBUG] Response code: 200

• Confirm LED blinks once (success) for each button press.
• Once all 6 buttons work on the breadboard, proceed to the final box.
• Drill 2.4 in holes in the remote enclosure (item 18) for all 6 buttons using the step drill bit — same layout as the Pi button box.
• Mount buttons in the holes and tighten the plastic ring nuts.
• Wire buttons to ESP32 using Dupont wires per the table.

TEST 11.1 — All 6 buttons work wirelessly

With the Pi running and the remote wired, press each button and verify:

• Green → TV video pauses or resumes
• Left Blue → previous video plays on TV
• Right Blue → next video plays on TV
• Left White → volume decreases (watch OSD on TV)
• Right White → volume increases
• Red → YouTube starts playing

Range test: Walk to the far end of the room and press buttons — they should still work. WiFi range in a typical home is 30–50 ft through walls.

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2.4 Step 12 — Wire battery power and assemble remote box

Parts needed: 3×AA battery holder with switch (item 16), AA batteries (item 17), remote enclosure box (item 18), rubber feet (item 19)

2.4.1 Tasks

• Insert 3 AA batteries into the battery holder.
• Connect the battery holder red wire to the ESP32 VIN pin.
• Connect the battery holder black wire to any ESP32 GND pin.
• Flip the battery holder switch to OFF.
• Disconnect the USB cable from the ESP32.
• Flip the switch to ON — the LED on the ESP32 should blink 3 times indicating WiFi connected.
• Press the green button — the video on the TV should pause or resume.
• Fit the ESP32 board and battery holder inside the remote box — use a small strip of double-sided foam tape to hold them in place.
• Route all button wires neatly and close the box (drill a small hole for the battery switch to poke through the side).
• Stick 4 rubber feet to the bottom of the remote box.
• Print and laminate the button labels and stick them on top of the box next to each button.

TEST 12.1 — Battery power works

1. Turn the remote switch to ON.
2. LED blinks 3 times = connected.
3. Press every button — all 6 should work.
4. Turn switch to OFF — LED goes dark.
5. Turn back ON — blinks 3 times again within ~5 seconds.

TEST 12.2 — Fully wireless end-to-end test

1. Power off and unplug everything.
2. Plug the Pi back in — wait 60 seconds for boot.
3. Video starts playing on TV automatically.
4. Turn the remote switch ON.
5. Use only the remote buttons to control the player — no laptop, no keyboard, no phone.

If this test passes, the build is complete.

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3 Part 3 — Maintenance & Troubleshooting

3.1 Adding new videos

3.1.1 How to add new MP4 files

• Remove the 128GB media microSD from the USB card reader plugged into the Pi.
• Insert it into your laptop using a USB card reader.
• Copy new .mp4 files into the videos folder on the card.
• Eject the card safely and put it back in the Pi’s USB reader.
• Reboot the Pi — new videos will be picked up automatically.

3.2 Adding YouTube favorites

3.2.1 How to add YouTube URLs

• SSH into the Pi: ssh pi@mpvplayer.local
• Edit the YouTube file:

nano ~/mp4player/A-Data/youtube.txt

• Add one YouTube URL per line, for example:

https://www.youtube.com/watch?v=XXXXXXXXXXX
https://www.youtube.com/watch?v=YYYYYYYYYYY

• Press Ctrl+X, Y, Enter to save.
• Restart the player service:

sudo systemctl restart mp4player.service

3.3 Common problems

Problem	Most likely cause	Fix
TV shows no picture	Wrong HDMI input selected	Press TV’s INPUT button and cycle through inputs
Video does not start on boot	Service not running	SSH in and run sudo systemctl status mp4player.service
Remote button does nothing	WiFi disconnected	Check LED on ESP32 — if not lit, turn switch off/on
Remote LED blinks 2x on press	Pi server not reachable	Confirm Pi is powered on and IP address has not changed
No sound	TV volume or wrong audio output	Check TV volume; also try amixer set Master 80% via SSH
Video plays but is jerky	File format not H.264	Convert the video using HandBrake to H.264 MP4

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Build Complete — the senior can now enjoy their player with just 6 big buttons and no wires!