Wemos LOLIN32: Unterschied zwischen den Versionen

@@ Zeile 44: / Zeile 44: @@
 Unfortunately, no direct method of battery voltage measurement is built into the system.
-But it should be quite easy to implement such a thing: Use a voltage divider on the battery to get a 3.3V max. For a 4.2V cell, this can be achieved using a 27k and 100k resistor.
+But it should be quite easy to implement such a thing: Use a voltage divider on the battery to get a 1.1V max. For a 4.2V cell, this can be achieved using a 27k and 100k resistor.
+Note, that the ADC of the ESP32 is set to 1.1V range by default! You can use the attenuation but this is not available on every platform.
    ^  V_bat
    |
-   R1 = 27k
+   R1 = 100k
    |
    +----o ADC
    |
-   R2 = 100k
+   R2 = 27k
    |
   GND
-Now you can measure the voltage on the battery using the ADC. As the ADC is 12bit, you can get the actual voltage by multiplying the reading by ((27+100)/100) * 3.3 / 2**12, or in more general terms: ((R1 + R2) * V_ref) / (R2 * 2**Resolution).
+Now you can measure the voltage on the battery using the ADC. As the ADC is 12bit, you can get the actual voltage by multiplying the reading by ((27+100)/27) * 1.1 / 2**12, or in more general terms: ((R1 + R2) * V_ref) / (R2 * 2**Resolution).
 == Battery ==