ElectronicZoologyfield notes from the garage
Field Notes

The Guides

Step-by-step guides built on real hardware in the garage. Confirmed working means tested and verified. Untested means the code is written but not yet run on hardware.

Audio
MAX98357A I2S Series
Step 1 How to wire the MAX98357A I2S amp with ESP32 ✓ Confirmed Step 2 How to play audio from ESP32 with MAX98357A ✓ Confirmed Step 3 How to play multiple audio files from ESP32 with MAX98357A ✓ Confirmed Step 4 How to trigger audio sequences with a button on ESP32 with MAX98357A ⚙ WIP
How to play audio from ESP32 with PAM8403 ✓ Confirmed
Display
TFT_eSPI Library Tutorial
Step 1 How to set up TFT_eSPI with ESP32 ✓ Confirmed Step 2 How to use the ST7735 128x128 display with ESP32 ✓ Confirmed Step 3 How to use the ST7789 240x240 display with ESP32 ✓ Confirmed Step 4 How to configure the GC9A01 round display with TFT_eSPI ✓ Confirmed
How to use the GC9D01 160x160 round TFT display with ESP32 ⚙ WIP
GC9A01 Display Series
Step 1 How to wire the GC9A01 round display with ESP32 ✓ Confirmed Step 2 How to display custom images on the GC9A01 ✓ Confirmed Step 3 How to cycle images on the GC9A01 with batch conversion ✓ Confirmed
How to use the SSD1306 OLED display with ESP32 ✓ Confirmed
Interface
How to find your I2C address ✓ Confirmed
Memory
ESP32 Memory Series
ESP32 memory explained: flash, RAM, with PSRAM ✓ Confirmed Step 1 How ESP32 flash memory works ✓ Confirmed Step 2 How ESP32 RAM works ✓ Confirmed Step 3 How ESP32 PSRAM works ✓ Confirmed Step 4 Does ESP32 need PROGMEM? ✓ Confirmed Step 5 How to use ESP32 NVS for persistent storage ✓ Confirmed Step 6 How to log ESP32 boot count and uptime with LittleFS ✓ Confirmed Step 7 How to use LittleFS on ESP32 ✓ Confirmed Step 8 Compression - the Tardis treatment ⚠ Untested Step 9 Compression + PSRAM - the next dimension ⚠ Untested
How to keep a copy of your sketch in LittleFS ✓ Confirmed
Wireless
How to get your ESP32 MAC address ✓ Confirmed How to set a custom MAC address on ESP32 ✓ Confirmed
ESP-NOW Series
Step 1 How to use ESP-NOW to connect two ESP32s without a router ✓ Confirmed Step 2 How to build an ESP-NOW remote charger monitor with INA219 and OLED ⚙ WIP
Power
How to build an INA219 battery charger monitor with ESP32 and OLED ✓ Confirmed
Diagnostics
How to check a new ESP32 ✓ Confirmed