SPL-Meter

Sound Pressure Level meter for ESP-32 with MS5611 sensor and SSD1306 OLED.

First-time setup

1. Flash SPL-Meter.ino to your board and power it on.
2. Use single click to select the Config tab, then double click to enter it.
3. Inside Config, double click again to start WiFi setup.
4. The screen shows setup status, including hotspot SSID and AP IP while setup is running.
5. Connect your phone or computer to the device access point:
   • SSID: SPL-Meter
   • Password: password
6. The WiFiManager portal should open automatically.
7. Enter your local Wi-Fi credentials and save.
8. On success, the device shows a Setup complete indicator.

Button controls

• Single click: navigate through menu tabs.
• Double click on a menu tab: enter the selected tab.
• Config has separate screens:
  • Connected: shows WiFi details (double click does nothing).
  • Setup Idle: double click starts WiFi setup.
  • Setup Running: shows AP SSID/IP; single click cancels and turns off AP.
• During active WiFi setup, SPL sampling is paused to improve setup stability and reduce power spikes.
• WiFi setup auto-times out after 3 minutes if not completed.
• After successful WiFi setup, config portal exits and AP is turned off (STA-only mode).
• In Measure: single click goes back to menu, double click resets the meter (peak dB and frequency) to 0.
• In Power: single click goes back, double click turns the device OFF, triple click reboots.
• When device is OFF: screen turns off; hold the button for 3 seconds to power ON.
• Double click on Format: run format/reset immediately.

Connect after Wi-Fi setup

After local Wi-Fi is configured and connected:

1. Open the Config tab on the device.
2. Check the local IP address shown on screen.
3. From a phone/computer connected to the same Wi-Fi network, open that IP in a browser.
4. A live dashboard shows current SPL, peak SPL, current/peak frequency, SPL bar, plus auto-zoomed historical SPL and frequency charts.
5. Hover either chart to inspect the sample time, SPL value, and frequency value at that point.
6. Use the dashboard Reset Peaks button to reset peak dB/frequency without touching the device.

Change default AP credentials later

You can change the access point SSID and password in the WiFiManager portal fields:

• Access Point SSID
• Access Point Password

OTA update

This device is capable of OTA (Over-the-Air) firmware updates. When the WiFiManager config portal is active, use the Update page to upload new firmware over Wi-Fi.