# Wrong pin connection in Case 05 Water Level Alarming **URL:** \ **Category:** micro:bit\ **Created:** [August 24, 2026, 9:38pm UTC](https://forum.makecode.com/t/wrong-pin-connection-in-case-05-water-level-alarming/45561 "2026-08-24T21:38:47Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Meii](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@Meii](https://forum.makecode.com/u/Meii)\ **Post date:** [August 24, 2026, 9:38pm UTC](https://forum.makecode.com/t/wrong-pin-connection-in-case-05-water-level-alarming/45561/1 "2026-08-24T21:38:47Z")
I found a small problem in the Hardware connect part of Case 05 Water Level Alarming. In the picture, the **water level sensor and relay are connected to the wrong pins**. **Wrong:** Water level sensor → **P1** Relay → **P2** **Correct:** Water level sensor → **P2** Relay → **P1** I marked the wrong connection with a red circle in the picture below. This also matches the code in the tutorial. The code uses **P2** to read the water level sensor and **P1** to control the relay. After I changed the connections, the project worked correctly.I hope this can help fix the hardware connection picture in the tutorial! ![Screenshot 2026-08-22 at 7.24.23 PM](https://us1.discourse-cdn.com/flex020/uploads/makecode/original/3X/3/c/3c2e3acf9bd6703e43ac295e76dda41c0d5b7340.png) Tutorial: [https://wiki.elecfreaks.com/en/microbit/wisdom-life/microbit-smart-home-kit/smart\_home\_case\_05/](https://wiki.elecfreaks.com/en/microbit/wisdom-life/microbit-smart-home-kit/smart_home_case_05/) ---
**Author:** ![CoderBunnyGirl](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.makecode.com/coderbunnygirl/32/34875_2.png) [@CoderBunnyGirl](https://forum.makecode.com/u/CoderBunnyGirl)\ **Post date:** [August 24, 2026, 11:18pm UTC](https://forum.makecode.com/t/wrong-pin-connection-in-case-05-water-level-alarming/45561/2 "2026-08-24T23:18:38Z")
that makes sense