WiFi-controlled LED display solution with REST API, DHT22 sensor, and OTA updates for your home network.
+ The LED Matrix is a receiver β what you send to it is entirely up to you. + Here are some examples of how I use the displays across the apartment. +
-| Component | -Model / Type | -Features | -
|---|---|---|
| Microcontroller | -NodeMCU-32S ESP32 | -32-Bit Dual-Core 240MHz, WiFi + Bluetooth | -
| LED Display | -12Γ MAX7219 8x8 Module | -cascaded | -
| Sensor | -DHT22 (AM2302) | -Temperature Β±0.5Β°C, Humidity Β±2% | -
| Buzzer | -Passive Buzzer | -GPIO 16 PWM controlled via NPN transistor | -
| Power Supply | -USB-C oder externe 5V PSU | -5V for MAX7219, 3.3V internal for logic | -
LedMatrix Software V1.08 -NodeMCU-32S ESP32 (USB powered) - -POWER SUPPLY: - Micro USB βββ ESP32 (5V regulator generates 3.3V internal) - -SPI SIGNALS (MAX7219): - VIN 5V βββ MAX7219 VCC - GND βββ MAX7219 GND - GPIO 5 βββ MAX7219 CS (Chip Select) - GPIO 18 βββ MAX7219 CLK (Clock) - GPIO 23 βββ MAX7219 DIN (Data In) - Modul 1 DOUT β Modul 2 DIN β Modul 3 DIN - -DHT22 SENSOR: - GPIO 27 βββ DHT22 Data - 3V3 βββ DHT22 VCC - GND βββ DHT22 GND - -BUZZER: - GPIO 16 βββ Buzzer Control (via transistor) - GPIO 16 ββ1kΞ©ββ NPN Transistor BASE - NPN Transistor COLLECTOR βββ Buzzer + - NPN Transistor EMITTER βββ GND - Buzzer - βββ GND (ESP32) - -ANALOG INPUTS (optional): - GPIO 34 βββ Analog Sensor 1 - GPIO 35 βββ Analog Sensor 2 - GPIO 36 βββ Analog Sensor 3+
Always-on clock and date display in each room
+Current temperature and conditions from indoor sensors
+Live temperature and humidity from the on-board DHT22 sensor
+Notifications like "washing machine done" triggered via MQTT
+Any text or scrolling message via the REST API
+- Here are photos of various LED Matrix installations in the home network. The systems show different colors and configurations. +
+ Six LED Matrix units are deployed across the apartment, each mounted in its respective room. + Every unit consists of an ESP32 board with cascaded MAX7219 LED modules and a DHT22 sensor, + connected via SPI. The displays are powered through micro-USB or directly via the 5V pins.
| Component | +Model / Type | +Features | +
|---|---|---|
| Microcontroller | +NodeMCU-32S ESP32 | +32-Bit Dual-Core 240MHz, WiFi + Bluetooth | +
| LED Display | +12Γ MAX7219 8x8 Module | +cascaded | +
| Sensor | +DHT22 (AM2302) | +Temperature Β±0.5Β°C, Humidity Β±2% | +
| Buzzer | +Passive Buzzer | +GPIO 16 PWM controlled via NPN transistor | +
| Power Supply | +Micro USB or direct 5V pin | +5V for MAX7219, 3.3V internal for logic | +
LedMatrix Software V1.08 +NodeMCU-32S ESP32 (USB powered) + +POWER SUPPLY: + Micro USB βββ ESP32 (5V regulator generates 3.3V internal) + or: 5V Pin βββ ESP32 5V (bypassing USB regulator) + +SPI SIGNALS (MAX7219): + VIN 5V βββ MAX7219 VCC + GND βββ MAX7219 GND + GPIO 5 βββ MAX7219 CS (Chip Select) + GPIO 18 βββ MAX7219 CLK (Clock) + GPIO 23 βββ MAX7219 DIN (Data In) + Modul 1 DOUT β Modul 2 DIN β Modul 3 DIN + +DHT22 SENSOR: + GPIO 27 βββ DHT22 Data + 3V3 βββ DHT22 VCC + GND βββ DHT22 GND + +BUZZER: + GPIO 16 βββ Buzzer Control (via transistor) + GPIO 16 ββ1kΞ©ββ NPN Transistor BASE + NPN Transistor COLLECTOR βββ Buzzer + + NPN Transistor EMITTER βββ GND + Buzzer - βββ GND (ESP32) + +ANALOG INPUTS (optional): + GPIO 34 βββ Analog Sensor 1 + GPIO 35 βββ Analog Sensor 2 + GPIO 36 βββ Analog Sensor 3+
GET /version Response: v1.08 (dht)
GET /sound/erledigt Plays positive tone sequence
GET /sound/warnung Plays warning tone sequence
GET /sound/abgeschlossen -Plays success tone sequence+Plays completed tone sequence
- The code has been thoroughly reviewed and classified as production-ready. -
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