r/embedded•
jeyoung

[STM32] Is there a way to increase the maximum input voltage for LOW on a pin?

Tech question

I am trying to read signals from a DHT11 sensor. The low signals are not going low enough for the pin to read them as low. For example, the I/O characteristics say I should expect a Vil(max) of 1.74V, but the signal from DHT11 drops to 1.82V.

Is there a way to tell the MCU to consider 1.82V as the low on a particular pin?

Edit: Change supply to DHT to 3.3V and the LOW voltage is now ~2.5V as can be seen on the oscilloscope.

https://imgur.com/a/h2fhor8

Posted May 23, 2020, 11:58 AM UTC · edited

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