Olivier Mehani<p><strong>Water tank level sensor: 4–20mA current loop, ESPHome, and Home Assistant</strong></p><p><a href="https://blog.narf.ssji.net/2025/06/30/water-tank-level-sensor-4-20ma-current-loop-esphome-and-home-assistant/" rel="nofollow noopener noreferrer" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">blog.narf.ssji.net/2025/06/30/</span><span class="invisible">water-tank-level-sensor-4-20ma-current-loop-esphome-and-home-assistant/</span></a></p><p>Our house water comes from a rain water tank. I built an ESPHome device, based on an Olimex ESP32-PoE2, to interface a 4-20mA current-loop liquid pressure sensor, and keep track of the water level in Home Assistant.</p><p><a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://blog.narf.ssji.net/tag/clk_mode/" target="_blank">#clkMode</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://blog.narf.ssji.net/tag/electronics/" target="_blank">#electronics</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://blog.narf.ssji.net/tag/esphome/" target="_blank">#ESPHome</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://blog.narf.ssji.net/tag/homeassistant/" target="_blank">#HomeAssistant</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://blog.narf.ssji.net/tag/olimex-esp32-poe2/" target="_blank">#OlimexESP32PoE2</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://blog.narf.ssji.net/tag/water-tank-sensor/" target="_blank">#waterTankSensor</a></p>