From d1e790793058126bbb95d1f775828693c07560c1 Mon Sep 17 00:00:00 2001 From: Petr Kejval Date: Mon, 6 Mar 2023 20:23:01 +0100 Subject: [PATCH] Update resistance.rst (#2725) * Update resistance.rst Spent many hours to figure it out why my NTC reading are incorrect. Found out that ADC readings must be multiplied by 3.3 because built-in voltage divider on ADC pin on some boards. * Update resistance.rst --- components/sensor/resistance.rst | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/components/sensor/resistance.rst b/components/sensor/resistance.rst index 21d42c2c4..cc6ce039e 100644 --- a/components/sensor/resistance.rst +++ b/components/sensor/resistance.rst @@ -44,6 +44,19 @@ is close to GND (DOWNSTREAM) or it is closer to VCC (UPSTREAM). id: source_sensor pin: A0 +Note: +------------------------ +Some boards like NodeMCUv2 needs to multiply ADC reading by 3.3 to provide accurate result because they have built-in voltage divider on ADC pin (https://arduino.stackexchange.com/a/71952) + +.. code-block:: yaml + + # Example source sensor: + - platform: adc + id: source_sensor + pin: A0 + filters: + - multiply: 3.3 + Configuration variables: ------------------------