ESP32 survival guide

Working with ESP32 WROVER (camera enabled)


wrover_example.jpg

I decided to try an alternative to ESP32 cam boards which are limited in functionality due to all pins except 13 being reserved for the camera. The ESP2 WROVER boards, although less popular, offers certain advantages:

  • no need for an interface board or UART upload board
  • many more pins to use for motion sensors or other similar triggers
  • can be used as a standard ESP32 controller for other projects if needed
  • can be used with a slightly modified but otherwise standard ESP32 case

disadvantages:

  • lack of a flash LED (could add your own and possibly much brighter)
  • no memory card slot
  • no ability to add an external antenna

It took some time to solve a couple of issues I ran into. At first I assumed I had received bad hardware, but it turned out the setting in my Arduino IDE were simply wrong. Also I had the wrong camera type selected.

First of all, the cameras that ship with ESP32 Wrover boards are NOT the same ones we get with ESP32 cam boards.  Although both are technically  OV2640 cameras, I was not able to get those shipped with ESP32 cameras to work with my ESP32 WROOM.

screen.jpg

In my code I had to switch from:

#define CAMERA_MODEL_AI_THINKER

to:

#define CAMERA_MODEL_WROVER_KIT // Has PSRAM

Additionally, when uploading using the ESP32 WROVER Module, I was getting this error:

esp32 Sketch uses 1509765 bytes (115%) of program storage space. Maximum is 1310720 bytes.

This was fixed by setting the Partition Scheme in the arduino IDE to "huge" (see screen below)

2024-04-10_22-54.png

With these changes I was able to get the ESP32 WROVER and camera to work propery. 

See also: https://randomnerdtutorials.com/getting-started-freenove-esp32-wrover-cam/

creating graphics for monochrome lcd displays

 

 

See:  https://homelab.impressto.ca/image2hex.php

 

Remotely control an esp32 with a built-in web server and clourflare

 

cloudflared tunnel  create tunnel-name
cloudflared tunnel route dns tunnel-name tunnel.example.com
cloudflared tunnel run --url http://localhost:5467  tunnel-name

 

Update /etc/cloudflared/config.yml and add an entry: 

  - hostname: leds.impressto.ca
    service: http://192.168.0.192:80   

 

 

Pong Game - Introduction to ESP32

A fun pong game for the TTGO T-Display with sound effects. Choose your sound module:

The board

What You'll Learn

What You Need

Hardware

Choose one sound module:

Module Pros Cons
DFPlayer Mini Different sound per event, SD card holds many tracks Needs SD card and MP3 files
ISD1820 No SD card needed, record your own voice/sound Only one sound, no volume control

Software

How to Play

Onboard Buttons

  1. Left Button (GPIO 0) - Move paddle LEFT
  2. Right Button (GPIO 35) - Move paddle RIGHT

External Buttons (Optional)

You can add your own buttons for a better gaming experience!

Wiring external buttons:

Button leg 1 -----> GPIO pin (25 or 13)
Button leg 2 -----> GND

No resistor needed - the ESP32 has internal pull-up resistors!

Gameplay

Getting Started

Step 1: Upload the Code

  1. Connect your T-Display to your computer with a USB cable
  2. Open this folder in VS Code
  3. Click the PlatformIO: Upload button (→ arrow at the bottom)
  4. Wait for it to finish - the game will start automatically!

Step 2: Play the Game First!

Before wiring anything, play the game to understand when events happen:

Wiring Up Sound!

Pick one sound module and follow its wiring guide below. Then set the matching option in config.h.

Option A: DFPlayer Mini

The DFPlayer Mini plays MP3 files from a micro SD card. You can assign a different sound to each game event.

Wiring

T-Display          DFPlayer Mini
---------          -------------
GPIO 17 (TX) ----> RX  (through 1K resistor recommended)
GPIO 21 (RX) <---- TX
GPIO 22      <---- BUSY  (optional — detects when playing)
GND          ----> GND
5V           ----> VCC
                   SPK1 ----> Speaker (+)
                   SPK2 ----> Speaker (-)

Note: Use 5V for louder output. The 1K resistor on TX protects the DFPlayer's RX pin.

Setting Up Sound Files

  1. Format a micro SD card as FAT32
  2. Create a folder named mp3 in the root
  3. Name your sound files: 0001.mp3, 0002.mp3, 0003.mp3, etc.
  4. Insert the SD card into the DFPlayer
File Event
0001.mp3 Score milestone award (every 5 points by default)
0002.mp3 Paddle hit (regular)
0003.mp3 Score lost

Enable in config.h

#define DFPLAYER_ENABLED   1    // Enable DFPlayer
#define ISD1820_ENABLED    0    // Disable ISD1820

Option B: ISD1820 Voice Record Playback Module

The ISD1820 is the simplest way to add sound. It stores one recorded sound directly on the chip — no SD card, no MP3 files. Just record your voice or a sound effect by holding the REC button, and the ESP32 will trigger it during the game.

Recording Your Sound

  1. Power the ISD1820 (3.3V or 5V)
  2. Hold the REC button on the module and speak or make a sound into the microphone
  3. Release REC when done — the sound is saved permanently, even without power
  4. Press the PLAY button on the module to hear it back before wiring to the ESP32

Wiring

T-Display          ISD1820
---------          -------
GPIO 15      ----> P-E  (Play Edge-triggered)
GND          ----> GND
3.3V or 5V   ----> VCC
                   SP+  ----> Speaker (+)
                   SP-  ----> Speaker (-)

Important: Connect to the P-E pin (Play Edge), NOT the P-L pin. P-E plays the sound once when the pin goes HIGH, which is what we want.

Enable in config.h

#define DFPLAYER_ENABLED            0    // Disable DFPlayer
#define ISD1820_ENABLED             1    // Enable ISD1820
#define ISD1820_TRIGGER_PADDLE_HIT  1    // Play on paddle hit (1=yes, 0=no)
#define ISD1820_TRIGGER_SCORE_LOST  1    // Play on score lost (1=yes, 0=no)

No Sound Module?

That's fine too — just disable both in config.h:

#define DFPLAYER_ENABLED   0
#define ISD1820_ENABLED    0

The game runs perfectly without any sound hardware attached.

Game Events

Event When Does It Trigger? DFPlayer ISD1820
Wall Bounce Ball bounces off any wall ❌ ❌
Paddle Hit Ball hits your paddle ✅ regular sound ✅ (configurable)
Score Milestone Score reaches a multiple of 5 ✅ award sound ❌
Score Lost You miss the ball ✅ ✅ (configurable)

Customizing the Game

Open src/config.h to change settings:

// ---- DFPlayer ----
#define DFPLAYER_ENABLED   1     // 1 = enable, 0 = disable
#define DFPLAYER_TX_PIN    17
#define DFPLAYER_RX_PIN    21
#define DFPLAYER_VOLUME    10    // 0-30
#define TRACK_AWARD        1     // 0001.mp3 - plays at score milestones
#define TRACK_PADDLE_HIT   2     // 0002.mp3 - plays on regular paddle hit
#define TRACK_SCORE_LOST   3     // 0003.mp3 - plays on score lost
#define SCORE_MILESTONE_INTERVAL  5   // Award sound fires at 5, 10, 15, 20...

// ---- ISD1820 ----
#define ISD1820_ENABLED             0    // 1 = enable, 0 = disable
#define ISD1820_PLAY_PIN            15   // GPIO connected to P-E pin
#define ISD1820_TRIGGER_PADDLE_HIT  1    // 1 = trigger on paddle hit
#define ISD1820_TRIGGER_SCORE_LOST  1    // 1 = trigger on score lost

Other Fun Settings to Try

#define PADDLE_WIDTH     15    // Make paddle bigger = easier game
#define BALL_SPEED_START  3    // Higher number = slower ball
#define PADDLE_SPEED      2    // How fast paddle moves

// External button pins (set to -1 to disable)
#define EXT_BUTTON_DOWN  25    // External button - paddle left
#define EXT_BUTTON_UP    13    // External button - paddle right

Adding Your Own Event Code!

Want to customize what happens when game events occur? You can add your own custom code!

Where to Put Your Code

Open src/events.cpp - this is where all the event magic happens!

The file has 4 event functions you can modify:

void onWallBounce() {
  // This runs when the ball hits a wall
}

void onPaddleHit() {
  // This runs when you hit the ball
}

void onScoreGained() {
  // This runs when you score a point
}

void onScoreLost() {
  // This runs when you miss the ball
}

Project Files Overview

File What's Inside
src/main.cpp The game code (paddle, ball, score)
src/config.h Settings you can change (pins, speeds, sizes)
src/events.h List of event functions (don't change this)
src/events.cpp Your code goes here! Event implementations

T-Display Pinout

Here are the GPIO pins used in this project:

Pin Usage Notes
0 Left button Onboard button
13 External button Default: External LEFT button
15 ISD1820 P-E Trigger pin (when ISD1820 enabled)
17 DFPlayer TX Serial TX to DFPlayer RX (when DFPlayer enabled)
21 DFPlayer RX Serial RX from DFPlayer TX (when DFPlayer enabled)
22 DFPlayer BUSY Optional: detect when DFPlayer is playing
25 External button Default: External RIGHT button
26 Event pin Ball wall bounce
27 Event pin Ball paddle hit
32 Event pin Score gained
33 Event pin Score lost
35 Right button Onboard button (input only)

Troubleshooting

No sound from DFPlayer

No sound from ISD1820

Code won't upload

Game runs but no sound

Want to Learn More?

Features

Have fun learning electronics! 🚀