{"id":243033,"date":"2026-06-22T15:02:15","date_gmt":"2026-06-22T13:02:15","guid":{"rendered":"https:\/\/emariete.com\/co2-gadget-guia-salidas\/"},"modified":"2026-10-29T12:14:16","modified_gmt":"2026-10-29T11:14:16","slug":"co2-gadget-guide-to-outings","status":"publish","type":"post","link":"https:\/\/emariete.com\/en\/co2-gadget-guia-salidas\/","title":{"rendered":"Gadget CO\u2082 Output Guide: Buzzer, NeoPixel and Relays"},"content":{"rendered":"

Connecting an audible or visual alarm to your Gadget CO\u2082 monitor is straightforward: a piezoelectric buzzer, a NeoPixel LED strip or a relay to activate an extractor fan. The unified output system allows you to trigger any of these based on CO\u2082 thresholds with configurable hysteresis.<\/p>\n\n\n\n\n\n\n

\nDocumentation is currently being updated.<\/strong> We are currently reviewing and improving all our pages. You may come across some broken links or content that is still pending. If you spot anything that isn\u2019t working properly, please help us fix it at GitHub<\/a>.\n<\/div>\n\n\n\n\n\n
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Available departures<\/h2>\n\n\n
Departure<\/th>GPIO pins<\/th>Function<\/th><\/tr><\/thead>
Orange Relay<\/strong><\/td>GPIO 32 (depending on the board)<\/td>It is triggered when the orange level is reached<\/td><\/tr>
Red Relay<\/strong><\/td>GPIO 33 (depending on the board)<\/td>It is triggered when the red level is reached<\/td><\/tr>
NeoPixel<\/strong><\/td>GPIO 26 (depending on the board)<\/td>Configurable WS2812B LED strip<\/td><\/tr>
Buzzer<\/strong><\/td>GPIO 2 (depending on the board)<\/td>Passive buzzer with configurable tone and duration<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n

Relay mode vs LED mode<\/h2>\n\n\n

The orange and red outputs can operate in two modes: Relay<\/strong> (the orange outlet remains active even if the red one is activated, ideal for ventilation) or LED<\/strong> (the orange output switches off when the red one is activated). Configurable from Settings \u2192 Output Configuration \u2192 GPIO Outputs<\/strong>.<\/p>\n\n\n

NeoPixel (WS2812B)<\/h2>\n\n\n

Supports WS2812B addressable LED strips with the following type selection: NEOGRB, NEO<\/em>RGB, NEO_RGBW. Brightness adjustable from 0 to 255. Requires 5V (use a step-up converter if running on battery power).<\/p>\n\n\n

Buzzer<\/h2>\n\n\n

Configurable passive buzzer: pitch (300\u20132000 Hz), beep duration (50\u2013300 ms) and mode (OFF, once, every X seconds). It is automatically disabled within the menu to avoid causing a nuisance.<\/p>\n\n\n

Hysteresis<\/h2>\n\n\n

All departures have configurable hysteresis<\/strong> to prevent them from switching on and off continuously if the concentration fluctuates around the threshold.<\/p>\n\n\n

Notes<\/h2>\n\n\n