Skip to content
Merged
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 6 additions & 1 deletion doc/reference.rst
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,12 @@ either to read voltage at ADC pin, or to read module supply voltage
(VCC).

To read external voltage applied to ADC pin, use ``analogRead(A0)``.
Input voltage range is 0 — 1.0V.
Input voltage range of bare ESP8266 is 0 — 1.0V, however some many
boards may implement voltage dividers. To be on the safe side, <1.0V
can be tested. If e.g. 0.5V delivers values around ~512, then maximum
voltage is very likely to be 1.0V and 3.3V may harm the ESP8266.
However values around ~150 indicates that the maximum voltage is
likely to be 3.3V.

To read VCC voltage, use ``ESP.getVcc()`` and ADC pin must be kept
unconnected. Additionally, the following line has to be added to the
Expand Down