An ESP32 ESP-IDF project in PlatformIO using an OV2640 camera to send a picture via MQTT to a broker on a push-button signal: A Doorbell.
This project uses an ESP32 Devkit 1 board and an OV2640 breakout board. Also a push-button is used to "ring the bell". The button is wired up so it's low-active and connected to D33 on the ESP32. In the default configuration the camera needs to be wired up as shown below:
| Interface | Camera PIN | ESP32 Pin | Code define |
|---|---|---|---|
| SCCB Clock | SIOC | 27 | CONFIG_SCL |
| SCCB Data | SIOD | 26 | CONFIG_SDA |
| System Clock | XCLK | 21 | CONFIG_XCLK |
| Vertical Sync | VSYNC | 25 | CONFIG_VSYNC |
| Horizontal Reference | HREF | 23 | CONFIG_HREF |
| Pixel Clock | PCLK | 22 | CONFIG_PCLK |
| Pixel Data Bit 0 | D2 | 4 | CONFIG_D0 |
| Pixel Data Bit 1 | D3 | 5 | CONFIG_D1 |
| Pixel Data Bit 2 | D4 | 18 | CONFIG_D2 |
| Pixel Data Bit 3 | D5 | 19 | CONFIG_D3 |
| Pixel Data Bit 4 | D6 | 36 (VP) | CONFIG_D4 |
| Pixel Data Bit 5 | D7 | 39 (VN) | CONFIG_D5 |
| Pixel Data Bit 6 | D8 | 34 | CONFIG_D6 |
| Pixel Data Bit 7 | D9 | 35 | CONFIG_D7 |
| Camera Reset | RET | 32 | CONFIG_RESET |
| Camera Power Down | PWDN | 100k Pulldown to Gnd | |
| Power Supply 3.3V | 3V3 | 3V3 | |
| Ground | GND | GND |
To display if someone ringed the door and show the image taken, take a look at https://github.com/Thomseeen/Summerschool.MQTT_Doorbell_Client.